Removed the Requirement to Install Python and NodeJS (Now Bundled with Borealis)

Dependencies/Python/Lib/asyncio/__init__.py

@@ -0,0 +1,47 @@
+"""The asyncio package, tracking PEP 3156."""
+
+# flake8: noqa
+
+import sys
+
+# This relies on each of the submodules having an __all__ variable.
+from .base_events import *
+from .coroutines import *
+from .events import *
+from .exceptions import *
+from .futures import *
+from .locks import *
+from .protocols import *
+from .runners import *
+from .queues import *
+from .streams import *
+from .subprocess import *
+from .tasks import *
+from .taskgroups import *
+from .timeouts import *
+from .threads import *
+from .transports import *
+
+__all__ = (base_events.__all__ +
+           coroutines.__all__ +
+           events.__all__ +
+           exceptions.__all__ +
+           futures.__all__ +
+           locks.__all__ +
+           protocols.__all__ +
+           runners.__all__ +
+           queues.__all__ +
+           streams.__all__ +
+           subprocess.__all__ +
+           tasks.__all__ +
+           taskgroups.__all__ +
+           threads.__all__ +
+           timeouts.__all__ +
+           transports.__all__)
+
+if sys.platform == 'win32':  # pragma: no cover
+    from .windows_events import *
+    __all__ += windows_events.__all__
+else:
+    from .unix_events import *  # pragma: no cover
+    __all__ += unix_events.__all__

Dependencies/Python/Lib/asyncio/__main__.py

@@ -0,0 +1,204 @@
+import ast
+import asyncio
+import concurrent.futures
+import contextvars
+import inspect
+import os
+import site
+import sys
+import threading
+import types
+import warnings
+
+from _colorize import can_colorize, ANSIColors  # type: ignore[import-not-found]
+from _pyrepl.console import InteractiveColoredConsole
+
+from . import futures
+
+
+class AsyncIOInteractiveConsole(InteractiveColoredConsole):
+
+    def __init__(self, locals, loop):
+        super().__init__(locals, filename="<stdin>")
+        self.compile.compiler.flags |= ast.PyCF_ALLOW_TOP_LEVEL_AWAIT
+
+        self.loop = loop
+        self.context = contextvars.copy_context()
+
+    def runcode(self, code):
+        global return_code
+        future = concurrent.futures.Future()
+
+        def callback():
+            global return_code
+            global repl_future
+            global keyboard_interrupted
+
+            repl_future = None
+            keyboard_interrupted = False
+
+            func = types.FunctionType(code, self.locals)
+            try:
+                coro = func()
+            except SystemExit as se:
+                return_code = se.code
+                self.loop.stop()
+                return
+            except KeyboardInterrupt as ex:
+                keyboard_interrupted = True
+                future.set_exception(ex)
+                return
+            except BaseException as ex:
+                future.set_exception(ex)
+                return
+
+            if not inspect.iscoroutine(coro):
+                future.set_result(coro)
+                return
+
+            try:
+                repl_future = self.loop.create_task(coro, context=self.context)
+                futures._chain_future(repl_future, future)
+            except BaseException as exc:
+                future.set_exception(exc)
+
+        loop.call_soon_threadsafe(callback, context=self.context)
+
+        try:
+            return future.result()
+        except SystemExit as se:
+            return_code = se.code
+            self.loop.stop()
+            return
+        except BaseException:
+            if keyboard_interrupted:
+                self.write("\nKeyboardInterrupt\n")
+            else:
+                self.showtraceback()
+            return self.STATEMENT_FAILED
+
+class REPLThread(threading.Thread):
+
+    def run(self):
+        global return_code
+
+        try:
+            banner = (
+                f'asyncio REPL {sys.version} on {sys.platform}\n'
+                f'Use "await" directly instead of "asyncio.run()".\n'
+                f'Type "help", "copyright", "credits" or "license" '
+                f'for more information.\n'
+            )
+
+            console.write(banner)
+
+            if startup_path := os.getenv("PYTHONSTARTUP"):
+                sys.audit("cpython.run_startup", startup_path)
+
+                import tokenize
+                with tokenize.open(startup_path) as f:
+                    startup_code = compile(f.read(), startup_path, "exec")
+                    exec(startup_code, console.locals)
+
+            ps1 = getattr(sys, "ps1", ">>> ")
+            if can_colorize() and CAN_USE_PYREPL:
+                ps1 = f"{ANSIColors.BOLD_MAGENTA}{ps1}{ANSIColors.RESET}"
+            console.write(f"{ps1}import asyncio\n")
+
+            if CAN_USE_PYREPL:
+                from _pyrepl.simple_interact import (
+                    run_multiline_interactive_console,
+                )
+                try:
+                    run_multiline_interactive_console(console)
+                except SystemExit:
+                    # expected via the `exit` and `quit` commands
+                    pass
+                except BaseException:
+                    # unexpected issue
+                    console.showtraceback()
+                    console.write("Internal error, ")
+                    return_code = 1
+            else:
+                console.interact(banner="", exitmsg="")
+        finally:
+            warnings.filterwarnings(
+                'ignore',
+                message=r'^coroutine .* was never awaited$',
+                category=RuntimeWarning)
+
+            loop.call_soon_threadsafe(loop.stop)
+
+    def interrupt(self) -> None:
+        if not CAN_USE_PYREPL:
+            return
+
+        from _pyrepl.simple_interact import _get_reader
+        r = _get_reader()
+        if r.threading_hook is not None:
+            r.threading_hook.add("")  # type: ignore
+
+
+if __name__ == '__main__':
+    sys.audit("cpython.run_stdin")
+
+    if os.getenv('PYTHON_BASIC_REPL'):
+        CAN_USE_PYREPL = False
+    else:
+        from _pyrepl.main import CAN_USE_PYREPL
+
+    return_code = 0
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+
+    repl_locals = {'asyncio': asyncio}
+    for key in {'__name__', '__package__',
+                '__loader__', '__spec__',
+                '__builtins__', '__file__'}:
+        repl_locals[key] = locals()[key]
+
+    console = AsyncIOInteractiveConsole(repl_locals, loop)
+
+    repl_future = None
+    keyboard_interrupted = False
+
+    try:
+        import readline  # NoQA
+    except ImportError:
+        readline = None
+
+    interactive_hook = getattr(sys, "__interactivehook__", None)
+
+    if interactive_hook is not None:
+        sys.audit("cpython.run_interactivehook", interactive_hook)
+        interactive_hook()
+
+    if interactive_hook is site.register_readline:
+        # Fix the completer function to use the interactive console locals
+        try:
+            import rlcompleter
+        except:
+            pass
+        else:
+            if readline is not None:
+                completer = rlcompleter.Completer(console.locals)
+                readline.set_completer(completer.complete)
+
+    repl_thread = REPLThread(name="Interactive thread")
+    repl_thread.daemon = True
+    repl_thread.start()
+
+    while True:
+        try:
+            loop.run_forever()
+        except KeyboardInterrupt:
+            keyboard_interrupted = True
+            if repl_future and not repl_future.done():
+                repl_future.cancel()
+            repl_thread.interrupt()
+            continue
+        else:
+            break
+
+    console.write('exiting asyncio REPL...\n')
+    sys.exit(return_code)

Dependencies/Python/Lib/asyncio/base_futures.py

@@ -0,0 +1,67 @@
+__all__ = ()
+
+import reprlib
+
+from . import format_helpers
+
+# States for Future.
+_PENDING = 'PENDING'
+_CANCELLED = 'CANCELLED'
+_FINISHED = 'FINISHED'
+
+
+def isfuture(obj):
+    """Check for a Future.
+
+    This returns True when obj is a Future instance or is advertising
+    itself as duck-type compatible by setting _asyncio_future_blocking.
+    See comment in Future for more details.
+    """
+    return (hasattr(obj.__class__, '_asyncio_future_blocking') and
+            obj._asyncio_future_blocking is not None)
+
+
+def _format_callbacks(cb):
+    """helper function for Future.__repr__"""
+    size = len(cb)
+    if not size:
+        cb = ''
+
+    def format_cb(callback):
+        return format_helpers._format_callback_source(callback, ())
+
+    if size == 1:
+        cb = format_cb(cb[0][0])
+    elif size == 2:
+        cb = '{}, {}'.format(format_cb(cb[0][0]), format_cb(cb[1][0]))
+    elif size > 2:
+        cb = '{}, <{} more>, {}'.format(format_cb(cb[0][0]),
+                                        size - 2,
+                                        format_cb(cb[-1][0]))
+    return f'cb=[{cb}]'
+
+
+def _future_repr_info(future):
+    # (Future) -> str
+    """helper function for Future.__repr__"""
+    info = [future._state.lower()]
+    if future._state == _FINISHED:
+        if future._exception is not None:
+            info.append(f'exception={future._exception!r}')
+        else:
+            # use reprlib to limit the length of the output, especially
+            # for very long strings
+            result = reprlib.repr(future._result)
+            info.append(f'result={result}')
+    if future._callbacks:
+        info.append(_format_callbacks(future._callbacks))
+    if future._source_traceback:
+        frame = future._source_traceback[-1]
+        info.append(f'created at {frame[0]}:{frame[1]}')
+    return info
+
+
+@reprlib.recursive_repr()
+def _future_repr(future):
+    info = ' '.join(_future_repr_info(future))
+    return f'<{future.__class__.__name__} {info}>'

Dependencies/Python/Lib/asyncio/base_subprocess.py

@@ -0,0 +1,303 @@
+import collections
+import subprocess
+import warnings
+import os
+import signal
+import sys
+
+from . import protocols
+from . import transports
+from .log import logger
+
+
+class BaseSubprocessTransport(transports.SubprocessTransport):
+
+    def __init__(self, loop, protocol, args, shell,
+                 stdin, stdout, stderr, bufsize,
+                 waiter=None, extra=None, **kwargs):
+        super().__init__(extra)
+        self._closed = False
+        self._protocol = protocol
+        self._loop = loop
+        self._proc = None
+        self._pid = None
+        self._returncode = None
+        self._exit_waiters = []
+        self._pending_calls = collections.deque()
+        self._pipes = {}
+        self._finished = False
+
+        if stdin == subprocess.PIPE:
+            self._pipes[0] = None
+        if stdout == subprocess.PIPE:
+            self._pipes[1] = None
+        if stderr == subprocess.PIPE:
+            self._pipes[2] = None
+
+        # Create the child process: set the _proc attribute
+        try:
+            self._start(args=args, shell=shell, stdin=stdin, stdout=stdout,
+                        stderr=stderr, bufsize=bufsize, **kwargs)
+        except:
+            self.close()
+            raise
+
+        self._pid = self._proc.pid
+        self._extra['subprocess'] = self._proc
+
+        if self._loop.get_debug():
+            if isinstance(args, (bytes, str)):
+                program = args
+            else:
+                program = args[0]
+            logger.debug('process %r created: pid %s',
+                         program, self._pid)
+
+        self._loop.create_task(self._connect_pipes(waiter))
+
+    def __repr__(self):
+        info = [self.__class__.__name__]
+        if self._closed:
+            info.append('closed')
+        if self._pid is not None:
+            info.append(f'pid={self._pid}')
+        if self._returncode is not None:
+            info.append(f'returncode={self._returncode}')
+        elif self._pid is not None:
+            info.append('running')
+        else:
+            info.append('not started')
+
+        stdin = self._pipes.get(0)
+        if stdin is not None:
+            info.append(f'stdin={stdin.pipe}')
+
+        stdout = self._pipes.get(1)
+        stderr = self._pipes.get(2)
+        if stdout is not None and stderr is stdout:
+            info.append(f'stdout=stderr={stdout.pipe}')
+        else:
+            if stdout is not None:
+                info.append(f'stdout={stdout.pipe}')
+            if stderr is not None:
+                info.append(f'stderr={stderr.pipe}')
+
+        return '<{}>'.format(' '.join(info))
+
+    def _start(self, args, shell, stdin, stdout, stderr, bufsize, **kwargs):
+        raise NotImplementedError
+
+    def set_protocol(self, protocol):
+        self._protocol = protocol
+
+    def get_protocol(self):
+        return self._protocol
+
+    def is_closing(self):
+        return self._closed
+
+    def close(self):
+        if self._closed:
+            return
+        self._closed = True
+
+        for proto in self._pipes.values():
+            if proto is None:
+                continue
+            proto.pipe.close()
+
+        if (self._proc is not None and
+                # has the child process finished?
+                self._returncode is None and
+                # the child process has finished, but the
+                # transport hasn't been notified yet?
+                self._proc.poll() is None):
+
+            if self._loop.get_debug():
+                logger.warning('Close running child process: kill %r', self)
+
+            try:
+                self._proc.kill()
+            except (ProcessLookupError, PermissionError):
+                # the process may have already exited or may be running setuid
+                pass
+
+            # Don't clear the _proc reference yet: _post_init() may still run
+
+    def __del__(self, _warn=warnings.warn):
+        if not self._closed:
+            _warn(f"unclosed transport {self!r}", ResourceWarning, source=self)
+            self.close()
+
+    def get_pid(self):
+        return self._pid
+
+    def get_returncode(self):
+        return self._returncode
+
+    def get_pipe_transport(self, fd):
+        if fd in self._pipes:
+            return self._pipes[fd].pipe
+        else:
+            return None
+
+    def _check_proc(self):
+        if self._proc is None:
+            raise ProcessLookupError()
+
+    if sys.platform == 'win32':
+        def send_signal(self, signal):
+            self._check_proc()
+            self._proc.send_signal(signal)
+
+        def terminate(self):
+            self._check_proc()
+            self._proc.terminate()
+
+        def kill(self):
+            self._check_proc()
+            self._proc.kill()
+    else:
+        def send_signal(self, signal):
+            self._check_proc()
+            try:
+                os.kill(self._proc.pid, signal)
+            except ProcessLookupError:
+                pass
+
+        def terminate(self):
+            self.send_signal(signal.SIGTERM)
+
+        def kill(self):
+            self.send_signal(signal.SIGKILL)
+
+    async def _connect_pipes(self, waiter):
+        try:
+            proc = self._proc
+            loop = self._loop
+
+            if proc.stdin is not None:
+                _, pipe = await loop.connect_write_pipe(
+                    lambda: WriteSubprocessPipeProto(self, 0),
+                    proc.stdin)
+                self._pipes[0] = pipe
+
+            if proc.stdout is not None:
+                _, pipe = await loop.connect_read_pipe(
+                    lambda: ReadSubprocessPipeProto(self, 1),
+                    proc.stdout)
+                self._pipes[1] = pipe
+
+            if proc.stderr is not None:
+                _, pipe = await loop.connect_read_pipe(
+                    lambda: ReadSubprocessPipeProto(self, 2),
+                    proc.stderr)
+                self._pipes[2] = pipe
+
+            assert self._pending_calls is not None
+
+            loop.call_soon(self._protocol.connection_made, self)
+            for callback, data in self._pending_calls:
+                loop.call_soon(callback, *data)
+            self._pending_calls = None
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as exc:
+            if waiter is not None and not waiter.cancelled():
+                waiter.set_exception(exc)
+        else:
+            if waiter is not None and not waiter.cancelled():
+                waiter.set_result(None)
+
+    def _call(self, cb, *data):
+        if self._pending_calls is not None:
+            self._pending_calls.append((cb, data))
+        else:
+            self._loop.call_soon(cb, *data)
+
+    def _pipe_connection_lost(self, fd, exc):
+        self._call(self._protocol.pipe_connection_lost, fd, exc)
+        self._try_finish()
+
+    def _pipe_data_received(self, fd, data):
+        self._call(self._protocol.pipe_data_received, fd, data)
+
+    def _process_exited(self, returncode):
+        assert returncode is not None, returncode
+        assert self._returncode is None, self._returncode
+        if self._loop.get_debug():
+            logger.info('%r exited with return code %r', self, returncode)
+        self._returncode = returncode
+        if self._proc.returncode is None:
+            # asyncio uses a child watcher: copy the status into the Popen
+            # object. On Python 3.6, it is required to avoid a ResourceWarning.
+            self._proc.returncode = returncode
+        self._call(self._protocol.process_exited)
+
+        self._try_finish()
+
+    async def _wait(self):
+        """Wait until the process exit and return the process return code.
+
+        This method is a coroutine."""
+        if self._returncode is not None:
+            return self._returncode
+
+        waiter = self._loop.create_future()
+        self._exit_waiters.append(waiter)
+        return await waiter
+
+    def _try_finish(self):
+        assert not self._finished
+        if self._returncode is None:
+            return
+        if all(p is not None and p.disconnected
+               for p in self._pipes.values()):
+            self._finished = True
+            self._call(self._call_connection_lost, None)
+
+    def _call_connection_lost(self, exc):
+        try:
+            self._protocol.connection_lost(exc)
+        finally:
+            # wake up futures waiting for wait()
+            for waiter in self._exit_waiters:
+                if not waiter.cancelled():
+                    waiter.set_result(self._returncode)
+            self._exit_waiters = None
+            self._loop = None
+            self._proc = None
+            self._protocol = None
+
+
+class WriteSubprocessPipeProto(protocols.BaseProtocol):
+
+    def __init__(self, proc, fd):
+        self.proc = proc
+        self.fd = fd
+        self.pipe = None
+        self.disconnected = False
+
+    def connection_made(self, transport):
+        self.pipe = transport
+
+    def __repr__(self):
+        return f'<{self.__class__.__name__} fd={self.fd} pipe={self.pipe!r}>'
+
+    def connection_lost(self, exc):
+        self.disconnected = True
+        self.proc._pipe_connection_lost(self.fd, exc)
+        self.proc = None
+
+    def pause_writing(self):
+        self.proc._protocol.pause_writing()
+
+    def resume_writing(self):
+        self.proc._protocol.resume_writing()
+
+
+class ReadSubprocessPipeProto(WriteSubprocessPipeProto,
+                              protocols.Protocol):
+
+    def data_received(self, data):
+        self.proc._pipe_data_received(self.fd, data)

Dependencies/Python/Lib/asyncio/base_tasks.py

@@ -0,0 +1,94 @@
+import linecache
+import reprlib
+import traceback
+
+from . import base_futures
+from . import coroutines
+
+
+def _task_repr_info(task):
+    info = base_futures._future_repr_info(task)
+
+    if task.cancelling() and not task.done():
+        # replace status
+        info[0] = 'cancelling'
+
+    info.insert(1, 'name=%r' % task.get_name())
+
+    if task._fut_waiter is not None:
+        info.insert(2, f'wait_for={task._fut_waiter!r}')
+
+    if task._coro:
+        coro = coroutines._format_coroutine(task._coro)
+        info.insert(2, f'coro=<{coro}>')
+
+    return info
+
+
+@reprlib.recursive_repr()
+def _task_repr(task):
+    info = ' '.join(_task_repr_info(task))
+    return f'<{task.__class__.__name__} {info}>'
+
+
+def _task_get_stack(task, limit):
+    frames = []
+    if hasattr(task._coro, 'cr_frame'):
+        # case 1: 'async def' coroutines
+        f = task._coro.cr_frame
+    elif hasattr(task._coro, 'gi_frame'):
+        # case 2: legacy coroutines
+        f = task._coro.gi_frame
+    elif hasattr(task._coro, 'ag_frame'):
+        # case 3: async generators
+        f = task._coro.ag_frame
+    else:
+        # case 4: unknown objects
+        f = None
+    if f is not None:
+        while f is not None:
+            if limit is not None:
+                if limit <= 0:
+                    break
+                limit -= 1
+            frames.append(f)
+            f = f.f_back
+        frames.reverse()
+    elif task._exception is not None:
+        tb = task._exception.__traceback__
+        while tb is not None:
+            if limit is not None:
+                if limit <= 0:
+                    break
+                limit -= 1
+            frames.append(tb.tb_frame)
+            tb = tb.tb_next
+    return frames
+
+
+def _task_print_stack(task, limit, file):
+    extracted_list = []
+    checked = set()
+    for f in task.get_stack(limit=limit):
+        lineno = f.f_lineno
+        co = f.f_code
+        filename = co.co_filename
+        name = co.co_name
+        if filename not in checked:
+            checked.add(filename)
+            linecache.checkcache(filename)
+        line = linecache.getline(filename, lineno, f.f_globals)
+        extracted_list.append((filename, lineno, name, line))
+
+    exc = task._exception
+    if not extracted_list:
+        print(f'No stack for {task!r}', file=file)
+    elif exc is not None:
+        print(f'Traceback for {task!r} (most recent call last):', file=file)
+    else:
+        print(f'Stack for {task!r} (most recent call last):', file=file)
+
+    traceback.print_list(extracted_list, file=file)
+    if exc is not None:
+        for line in traceback.format_exception_only(exc.__class__, exc):
+            print(line, file=file, end='')

Dependencies/Python/Lib/asyncio/constants.py

@@ -0,0 +1,41 @@
+# Contains code from https://github.com/MagicStack/uvloop/tree/v0.16.0
+# SPDX-License-Identifier: PSF-2.0 AND (MIT OR Apache-2.0)
+# SPDX-FileCopyrightText: Copyright (c) 2015-2021 MagicStack Inc.  http://magic.io
+
+import enum
+
+# After the connection is lost, log warnings after this many write()s.
+LOG_THRESHOLD_FOR_CONNLOST_WRITES = 5
+
+# Seconds to wait before retrying accept().
+ACCEPT_RETRY_DELAY = 1
+
+# Number of stack entries to capture in debug mode.
+# The larger the number, the slower the operation in debug mode
+# (see extract_stack() in format_helpers.py).
+DEBUG_STACK_DEPTH = 10
+
+# Number of seconds to wait for SSL handshake to complete
+# The default timeout matches that of Nginx.
+SSL_HANDSHAKE_TIMEOUT = 60.0
+
+# Number of seconds to wait for SSL shutdown to complete
+# The default timeout mimics lingering_time
+SSL_SHUTDOWN_TIMEOUT = 30.0
+
+# Used in sendfile fallback code.  We use fallback for platforms
+# that don't support sendfile, or for TLS connections.
+SENDFILE_FALLBACK_READBUFFER_SIZE = 1024 * 256
+
+FLOW_CONTROL_HIGH_WATER_SSL_READ = 256  # KiB
+FLOW_CONTROL_HIGH_WATER_SSL_WRITE = 512  # KiB
+
+# Default timeout for joining the threads in the threadpool
+THREAD_JOIN_TIMEOUT = 300
+
+# The enum should be here to break circular dependencies between
+# base_events and sslproto
+class _SendfileMode(enum.Enum):
+    UNSUPPORTED = enum.auto()
+    TRY_NATIVE = enum.auto()
+    FALLBACK = enum.auto()

Dependencies/Python/Lib/asyncio/coroutines.py

@@ -0,0 +1,109 @@
+__all__ = 'iscoroutinefunction', 'iscoroutine'
+
+import collections.abc
+import inspect
+import os
+import sys
+import types
+
+
+def _is_debug_mode():
+    # See: https://docs.python.org/3/library/asyncio-dev.html#asyncio-debug-mode.
+    return sys.flags.dev_mode or (not sys.flags.ignore_environment and
+                                  bool(os.environ.get('PYTHONASYNCIODEBUG')))
+
+
+# A marker for iscoroutinefunction.
+_is_coroutine = object()
+
+
+def iscoroutinefunction(func):
+    """Return True if func is a decorated coroutine function."""
+    return (inspect.iscoroutinefunction(func) or
+            getattr(func, '_is_coroutine', None) is _is_coroutine)
+
+
+# Prioritize native coroutine check to speed-up
+# asyncio.iscoroutine.
+_COROUTINE_TYPES = (types.CoroutineType, collections.abc.Coroutine)
+_iscoroutine_typecache = set()
+
+
+def iscoroutine(obj):
+    """Return True if obj is a coroutine object."""
+    if type(obj) in _iscoroutine_typecache:
+        return True
+
+    if isinstance(obj, _COROUTINE_TYPES):
+        # Just in case we don't want to cache more than 100
+        # positive types.  That shouldn't ever happen, unless
+        # someone stressing the system on purpose.
+        if len(_iscoroutine_typecache) < 100:
+            _iscoroutine_typecache.add(type(obj))
+        return True
+    else:
+        return False
+
+
+def _format_coroutine(coro):
+    assert iscoroutine(coro)
+
+    def get_name(coro):
+        # Coroutines compiled with Cython sometimes don't have
+        # proper __qualname__ or __name__.  While that is a bug
+        # in Cython, asyncio shouldn't crash with an AttributeError
+        # in its __repr__ functions.
+        if hasattr(coro, '__qualname__') and coro.__qualname__:
+            coro_name = coro.__qualname__
+        elif hasattr(coro, '__name__') and coro.__name__:
+            coro_name = coro.__name__
+        else:
+            # Stop masking Cython bugs, expose them in a friendly way.
+            coro_name = f'<{type(coro).__name__} without __name__>'
+        return f'{coro_name}()'
+
+    def is_running(coro):
+        try:
+            return coro.cr_running
+        except AttributeError:
+            try:
+                return coro.gi_running
+            except AttributeError:
+                return False
+
+    coro_code = None
+    if hasattr(coro, 'cr_code') and coro.cr_code:
+        coro_code = coro.cr_code
+    elif hasattr(coro, 'gi_code') and coro.gi_code:
+        coro_code = coro.gi_code
+
+    coro_name = get_name(coro)
+
+    if not coro_code:
+        # Built-in types might not have __qualname__ or __name__.
+        if is_running(coro):
+            return f'{coro_name} running'
+        else:
+            return coro_name
+
+    coro_frame = None
+    if hasattr(coro, 'gi_frame') and coro.gi_frame:
+        coro_frame = coro.gi_frame
+    elif hasattr(coro, 'cr_frame') and coro.cr_frame:
+        coro_frame = coro.cr_frame
+
+    # If Cython's coroutine has a fake code object without proper
+    # co_filename -- expose that.
+    filename = coro_code.co_filename or '<empty co_filename>'
+
+    lineno = 0
+
+    if coro_frame is not None:
+        lineno = coro_frame.f_lineno
+        coro_repr = f'{coro_name} running at {filename}:{lineno}'
+
+    else:
+        lineno = coro_code.co_firstlineno
+        coro_repr = f'{coro_name} done, defined at {filename}:{lineno}'
+
+    return coro_repr

Dependencies/Python/Lib/asyncio/events.py

@@ -0,0 +1,882 @@
+"""Event loop and event loop policy."""
+
+# Contains code from https://github.com/MagicStack/uvloop/tree/v0.16.0
+# SPDX-License-Identifier: PSF-2.0 AND (MIT OR Apache-2.0)
+# SPDX-FileCopyrightText: Copyright (c) 2015-2021 MagicStack Inc.  http://magic.io
+
+__all__ = (
+    'AbstractEventLoopPolicy',
+    'AbstractEventLoop', 'AbstractServer',
+    'Handle', 'TimerHandle',
+    'get_event_loop_policy', 'set_event_loop_policy',
+    'get_event_loop', 'set_event_loop', 'new_event_loop',
+    'get_child_watcher', 'set_child_watcher',
+    '_set_running_loop', 'get_running_loop',
+    '_get_running_loop',
+)
+
+import contextvars
+import os
+import signal
+import socket
+import subprocess
+import sys
+import threading
+
+from . import format_helpers
+
+
+class Handle:
+    """Object returned by callback registration methods."""
+
+    __slots__ = ('_callback', '_args', '_cancelled', '_loop',
+                 '_source_traceback', '_repr', '__weakref__',
+                 '_context')
+
+    def __init__(self, callback, args, loop, context=None):
+        if context is None:
+            context = contextvars.copy_context()
+        self._context = context
+        self._loop = loop
+        self._callback = callback
+        self._args = args
+        self._cancelled = False
+        self._repr = None
+        if self._loop.get_debug():
+            self._source_traceback = format_helpers.extract_stack(
+                sys._getframe(1))
+        else:
+            self._source_traceback = None
+
+    def _repr_info(self):
+        info = [self.__class__.__name__]
+        if self._cancelled:
+            info.append('cancelled')
+        if self._callback is not None:
+            info.append(format_helpers._format_callback_source(
+                self._callback, self._args,
+                debug=self._loop.get_debug()))
+        if self._source_traceback:
+            frame = self._source_traceback[-1]
+            info.append(f'created at {frame[0]}:{frame[1]}')
+        return info
+
+    def __repr__(self):
+        if self._repr is not None:
+            return self._repr
+        info = self._repr_info()
+        return '<{}>'.format(' '.join(info))
+
+    def get_context(self):
+        return self._context
+
+    def cancel(self):
+        if not self._cancelled:
+            self._cancelled = True
+            if self._loop.get_debug():
+                # Keep a representation in debug mode to keep callback and
+                # parameters. For example, to log the warning
+                # "Executing <Handle...> took 2.5 second"
+                self._repr = repr(self)
+            self._callback = None
+            self._args = None
+
+    def cancelled(self):
+        return self._cancelled
+
+    def _run(self):
+        try:
+            self._context.run(self._callback, *self._args)
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as exc:
+            cb = format_helpers._format_callback_source(
+                self._callback, self._args,
+                debug=self._loop.get_debug())
+            msg = f'Exception in callback {cb}'
+            context = {
+                'message': msg,
+                'exception': exc,
+                'handle': self,
+            }
+            if self._source_traceback:
+                context['source_traceback'] = self._source_traceback
+            self._loop.call_exception_handler(context)
+        self = None  # Needed to break cycles when an exception occurs.
+
+
+class TimerHandle(Handle):
+    """Object returned by timed callback registration methods."""
+
+    __slots__ = ['_scheduled', '_when']
+
+    def __init__(self, when, callback, args, loop, context=None):
+        super().__init__(callback, args, loop, context)
+        if self._source_traceback:
+            del self._source_traceback[-1]
+        self._when = when
+        self._scheduled = False
+
+    def _repr_info(self):
+        info = super()._repr_info()
+        pos = 2 if self._cancelled else 1
+        info.insert(pos, f'when={self._when}')
+        return info
+
+    def __hash__(self):
+        return hash(self._when)
+
+    def __lt__(self, other):
+        if isinstance(other, TimerHandle):
+            return self._when < other._when
+        return NotImplemented
+
+    def __le__(self, other):
+        if isinstance(other, TimerHandle):
+            return self._when < other._when or self.__eq__(other)
+        return NotImplemented
+
+    def __gt__(self, other):
+        if isinstance(other, TimerHandle):
+            return self._when > other._when
+        return NotImplemented
+
+    def __ge__(self, other):
+        if isinstance(other, TimerHandle):
+            return self._when > other._when or self.__eq__(other)
+        return NotImplemented
+
+    def __eq__(self, other):
+        if isinstance(other, TimerHandle):
+            return (self._when == other._when and
+                    self._callback == other._callback and
+                    self._args == other._args and
+                    self._cancelled == other._cancelled)
+        return NotImplemented
+
+    def cancel(self):
+        if not self._cancelled:
+            self._loop._timer_handle_cancelled(self)
+        super().cancel()
+
+    def when(self):
+        """Return a scheduled callback time.
+
+        The time is an absolute timestamp, using the same time
+        reference as loop.time().
+        """
+        return self._when
+
+
+class AbstractServer:
+    """Abstract server returned by create_server()."""
+
+    def close(self):
+        """Stop serving.  This leaves existing connections open."""
+        raise NotImplementedError
+
+    def close_clients(self):
+        """Close all active connections."""
+        raise NotImplementedError
+
+    def abort_clients(self):
+        """Close all active connections immediately."""
+        raise NotImplementedError
+
+    def get_loop(self):
+        """Get the event loop the Server object is attached to."""
+        raise NotImplementedError
+
+    def is_serving(self):
+        """Return True if the server is accepting connections."""
+        raise NotImplementedError
+
+    async def start_serving(self):
+        """Start accepting connections.
+
+        This method is idempotent, so it can be called when
+        the server is already being serving.
+        """
+        raise NotImplementedError
+
+    async def serve_forever(self):
+        """Start accepting connections until the coroutine is cancelled.
+
+        The server is closed when the coroutine is cancelled.
+        """
+        raise NotImplementedError
+
+    async def wait_closed(self):
+        """Coroutine to wait until service is closed."""
+        raise NotImplementedError
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, *exc):
+        self.close()
+        await self.wait_closed()
+
+
+class AbstractEventLoop:
+    """Abstract event loop."""
+
+    # Running and stopping the event loop.
+
+    def run_forever(self):
+        """Run the event loop until stop() is called."""
+        raise NotImplementedError
+
+    def run_until_complete(self, future):
+        """Run the event loop until a Future is done.
+
+        Return the Future's result, or raise its exception.
+        """
+        raise NotImplementedError
+
+    def stop(self):
+        """Stop the event loop as soon as reasonable.
+
+        Exactly how soon that is may depend on the implementation, but
+        no more I/O callbacks should be scheduled.
+        """
+        raise NotImplementedError
+
+    def is_running(self):
+        """Return whether the event loop is currently running."""
+        raise NotImplementedError
+
+    def is_closed(self):
+        """Returns True if the event loop was closed."""
+        raise NotImplementedError
+
+    def close(self):
+        """Close the loop.
+
+        The loop should not be running.
+
+        This is idempotent and irreversible.
+
+        No other methods should be called after this one.
+        """
+        raise NotImplementedError
+
+    async def shutdown_asyncgens(self):
+        """Shutdown all active asynchronous generators."""
+        raise NotImplementedError
+
+    async def shutdown_default_executor(self):
+        """Schedule the shutdown of the default executor."""
+        raise NotImplementedError
+
+    # Methods scheduling callbacks.  All these return Handles.
+
+    def _timer_handle_cancelled(self, handle):
+        """Notification that a TimerHandle has been cancelled."""
+        raise NotImplementedError
+
+    def call_soon(self, callback, *args, context=None):
+        return self.call_later(0, callback, *args, context=context)
+
+    def call_later(self, delay, callback, *args, context=None):
+        raise NotImplementedError
+
+    def call_at(self, when, callback, *args, context=None):
+        raise NotImplementedError
+
+    def time(self):
+        raise NotImplementedError
+
+    def create_future(self):
+        raise NotImplementedError
+
+    # Method scheduling a coroutine object: create a task.
+
+    def create_task(self, coro, **kwargs):
+        raise NotImplementedError
+
+    # Methods for interacting with threads.
+
+    def call_soon_threadsafe(self, callback, *args, context=None):
+        raise NotImplementedError
+
+    def run_in_executor(self, executor, func, *args):
+        raise NotImplementedError
+
+    def set_default_executor(self, executor):
+        raise NotImplementedError
+
+    # Network I/O methods returning Futures.
+
+    async def getaddrinfo(self, host, port, *,
+                          family=0, type=0, proto=0, flags=0):
+        raise NotImplementedError
+
+    async def getnameinfo(self, sockaddr, flags=0):
+        raise NotImplementedError
+
+    async def create_connection(
+            self, protocol_factory, host=None, port=None,
+            *, ssl=None, family=0, proto=0,
+            flags=0, sock=None, local_addr=None,
+            server_hostname=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
+            happy_eyeballs_delay=None, interleave=None):
+        raise NotImplementedError
+
+    async def create_server(
+            self, protocol_factory, host=None, port=None,
+            *, family=socket.AF_UNSPEC,
+            flags=socket.AI_PASSIVE, sock=None, backlog=100,
+            ssl=None, reuse_address=None, reuse_port=None,
+            keep_alive=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
+            start_serving=True):
+        """A coroutine which creates a TCP server bound to host and port.
+
+        The return value is a Server object which can be used to stop
+        the service.
+
+        If host is an empty string or None all interfaces are assumed
+        and a list of multiple sockets will be returned (most likely
+        one for IPv4 and another one for IPv6). The host parameter can also be
+        a sequence (e.g. list) of hosts to bind to.
+
+        family can be set to either AF_INET or AF_INET6 to force the
+        socket to use IPv4 or IPv6. If not set it will be determined
+        from host (defaults to AF_UNSPEC).
+
+        flags is a bitmask for getaddrinfo().
+
+        sock can optionally be specified in order to use a preexisting
+        socket object.
+
+        backlog is the maximum number of queued connections passed to
+        listen() (defaults to 100).
+
+        ssl can be set to an SSLContext to enable SSL over the
+        accepted connections.
+
+        reuse_address tells the kernel to reuse a local socket in
+        TIME_WAIT state, without waiting for its natural timeout to
+        expire. If not specified will automatically be set to True on
+        UNIX.
+
+        reuse_port tells the kernel to allow this endpoint to be bound to
+        the same port as other existing endpoints are bound to, so long as
+        they all set this flag when being created. This option is not
+        supported on Windows.
+
+        keep_alive set to True keeps connections active by enabling the
+        periodic transmission of messages.
+
+        ssl_handshake_timeout is the time in seconds that an SSL server
+        will wait for completion of the SSL handshake before aborting the
+        connection. Default is 60s.
+
+        ssl_shutdown_timeout is the time in seconds that an SSL server
+        will wait for completion of the SSL shutdown procedure
+        before aborting the connection. Default is 30s.
+
+        start_serving set to True (default) causes the created server
+        to start accepting connections immediately.  When set to False,
+        the user should await Server.start_serving() or Server.serve_forever()
+        to make the server to start accepting connections.
+        """
+        raise NotImplementedError
+
+    async def sendfile(self, transport, file, offset=0, count=None,
+                       *, fallback=True):
+        """Send a file through a transport.
+
+        Return an amount of sent bytes.
+        """
+        raise NotImplementedError
+
+    async def start_tls(self, transport, protocol, sslcontext, *,
+                        server_side=False,
+                        server_hostname=None,
+                        ssl_handshake_timeout=None,
+                        ssl_shutdown_timeout=None):
+        """Upgrade a transport to TLS.
+
+        Return a new transport that *protocol* should start using
+        immediately.
+        """
+        raise NotImplementedError
+
+    async def create_unix_connection(
+            self, protocol_factory, path=None, *,
+            ssl=None, sock=None,
+            server_hostname=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
+        raise NotImplementedError
+
+    async def create_unix_server(
+            self, protocol_factory, path=None, *,
+            sock=None, backlog=100, ssl=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
+            start_serving=True):
+        """A coroutine which creates a UNIX Domain Socket server.
+
+        The return value is a Server object, which can be used to stop
+        the service.
+
+        path is a str, representing a file system path to bind the
+        server socket to.
+
+        sock can optionally be specified in order to use a preexisting
+        socket object.
+
+        backlog is the maximum number of queued connections passed to
+        listen() (defaults to 100).
+
+        ssl can be set to an SSLContext to enable SSL over the
+        accepted connections.
+
+        ssl_handshake_timeout is the time in seconds that an SSL server
+        will wait for the SSL handshake to complete (defaults to 60s).
+
+        ssl_shutdown_timeout is the time in seconds that an SSL server
+        will wait for the SSL shutdown to finish (defaults to 30s).
+
+        start_serving set to True (default) causes the created server
+        to start accepting connections immediately.  When set to False,
+        the user should await Server.start_serving() or Server.serve_forever()
+        to make the server to start accepting connections.
+        """
+        raise NotImplementedError
+
+    async def connect_accepted_socket(
+            self, protocol_factory, sock,
+            *, ssl=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
+        """Handle an accepted connection.
+
+        This is used by servers that accept connections outside of
+        asyncio, but use asyncio to handle connections.
+
+        This method is a coroutine.  When completed, the coroutine
+        returns a (transport, protocol) pair.
+        """
+        raise NotImplementedError
+
+    async def create_datagram_endpoint(self, protocol_factory,
+                                       local_addr=None, remote_addr=None, *,
+                                       family=0, proto=0, flags=0,
+                                       reuse_address=None, reuse_port=None,
+                                       allow_broadcast=None, sock=None):
+        """A coroutine which creates a datagram endpoint.
+
+        This method will try to establish the endpoint in the background.
+        When successful, the coroutine returns a (transport, protocol) pair.
+
+        protocol_factory must be a callable returning a protocol instance.
+
+        socket family AF_INET, socket.AF_INET6 or socket.AF_UNIX depending on
+        host (or family if specified), socket type SOCK_DGRAM.
+
+        reuse_address tells the kernel to reuse a local socket in
+        TIME_WAIT state, without waiting for its natural timeout to
+        expire. If not specified it will automatically be set to True on
+        UNIX.
+
+        reuse_port tells the kernel to allow this endpoint to be bound to
+        the same port as other existing endpoints are bound to, so long as
+        they all set this flag when being created. This option is not
+        supported on Windows and some UNIX's. If the
+        :py:data:`~socket.SO_REUSEPORT` constant is not defined then this
+        capability is unsupported.
+
+        allow_broadcast tells the kernel to allow this endpoint to send
+        messages to the broadcast address.
+
+        sock can optionally be specified in order to use a preexisting
+        socket object.
+        """
+        raise NotImplementedError
+
+    # Pipes and subprocesses.
+
+    async def connect_read_pipe(self, protocol_factory, pipe):
+        """Register read pipe in event loop. Set the pipe to non-blocking mode.
+
+        protocol_factory should instantiate object with Protocol interface.
+        pipe is a file-like object.
+        Return pair (transport, protocol), where transport supports the
+        ReadTransport interface."""
+        # The reason to accept file-like object instead of just file descriptor
+        # is: we need to own pipe and close it at transport finishing
+        # Can got complicated errors if pass f.fileno(),
+        # close fd in pipe transport then close f and vice versa.
+        raise NotImplementedError
+
+    async def connect_write_pipe(self, protocol_factory, pipe):
+        """Register write pipe in event loop.
+
+        protocol_factory should instantiate object with BaseProtocol interface.
+        Pipe is file-like object already switched to nonblocking.
+        Return pair (transport, protocol), where transport support
+        WriteTransport interface."""
+        # The reason to accept file-like object instead of just file descriptor
+        # is: we need to own pipe and close it at transport finishing
+        # Can got complicated errors if pass f.fileno(),
+        # close fd in pipe transport then close f and vice versa.
+        raise NotImplementedError
+
+    async def subprocess_shell(self, protocol_factory, cmd, *,
+                               stdin=subprocess.PIPE,
+                               stdout=subprocess.PIPE,
+                               stderr=subprocess.PIPE,
+                               **kwargs):
+        raise NotImplementedError
+
+    async def subprocess_exec(self, protocol_factory, *args,
+                              stdin=subprocess.PIPE,
+                              stdout=subprocess.PIPE,
+                              stderr=subprocess.PIPE,
+                              **kwargs):
+        raise NotImplementedError
+
+    # Ready-based callback registration methods.
+    # The add_*() methods return None.
+    # The remove_*() methods return True if something was removed,
+    # False if there was nothing to delete.
+
+    def add_reader(self, fd, callback, *args):
+        raise NotImplementedError
+
+    def remove_reader(self, fd):
+        raise NotImplementedError
+
+    def add_writer(self, fd, callback, *args):
+        raise NotImplementedError
+
+    def remove_writer(self, fd):
+        raise NotImplementedError
+
+    # Completion based I/O methods returning Futures.
+
+    async def sock_recv(self, sock, nbytes):
+        raise NotImplementedError
+
+    async def sock_recv_into(self, sock, buf):
+        raise NotImplementedError
+
+    async def sock_recvfrom(self, sock, bufsize):
+        raise NotImplementedError
+
+    async def sock_recvfrom_into(self, sock, buf, nbytes=0):
+        raise NotImplementedError
+
+    async def sock_sendall(self, sock, data):
+        raise NotImplementedError
+
+    async def sock_sendto(self, sock, data, address):
+        raise NotImplementedError
+
+    async def sock_connect(self, sock, address):
+        raise NotImplementedError
+
+    async def sock_accept(self, sock):
+        raise NotImplementedError
+
+    async def sock_sendfile(self, sock, file, offset=0, count=None,
+                            *, fallback=None):
+        raise NotImplementedError
+
+    # Signal handling.
+
+    def add_signal_handler(self, sig, callback, *args):
+        raise NotImplementedError
+
+    def remove_signal_handler(self, sig):
+        raise NotImplementedError
+
+    # Task factory.
+
+    def set_task_factory(self, factory):
+        raise NotImplementedError
+
+    def get_task_factory(self):
+        raise NotImplementedError
+
+    # Error handlers.
+
+    def get_exception_handler(self):
+        raise NotImplementedError
+
+    def set_exception_handler(self, handler):
+        raise NotImplementedError
+
+    def default_exception_handler(self, context):
+        raise NotImplementedError
+
+    def call_exception_handler(self, context):
+        raise NotImplementedError
+
+    # Debug flag management.
+
+    def get_debug(self):
+        raise NotImplementedError
+
+    def set_debug(self, enabled):
+        raise NotImplementedError
+
+
+class AbstractEventLoopPolicy:
+    """Abstract policy for accessing the event loop."""
+
+    def get_event_loop(self):
+        """Get the event loop for the current context.
+
+        Returns an event loop object implementing the AbstractEventLoop interface,
+        or raises an exception in case no event loop has been set for the
+        current context and the current policy does not specify to create one.
+
+        It should never return None."""
+        raise NotImplementedError
+
+    def set_event_loop(self, loop):
+        """Set the event loop for the current context to loop."""
+        raise NotImplementedError
+
+    def new_event_loop(self):
+        """Create and return a new event loop object according to this
+        policy's rules. If there's need to set this loop as the event loop for
+        the current context, set_event_loop must be called explicitly."""
+        raise NotImplementedError
+
+    # Child processes handling (Unix only).
+
+    def get_child_watcher(self):
+        "Get the watcher for child processes."
+        raise NotImplementedError
+
+    def set_child_watcher(self, watcher):
+        """Set the watcher for child processes."""
+        raise NotImplementedError
+
+
+class BaseDefaultEventLoopPolicy(AbstractEventLoopPolicy):
+    """Default policy implementation for accessing the event loop.
+
+    In this policy, each thread has its own event loop.  However, we
+    only automatically create an event loop by default for the main
+    thread; other threads by default have no event loop.
+
+    Other policies may have different rules (e.g. a single global
+    event loop, or automatically creating an event loop per thread, or
+    using some other notion of context to which an event loop is
+    associated).
+    """
+
+    _loop_factory = None
+
+    class _Local(threading.local):
+        _loop = None
+        _set_called = False
+
+    def __init__(self):
+        self._local = self._Local()
+
+    def get_event_loop(self):
+        """Get the event loop for the current context.
+
+        Returns an instance of EventLoop or raises an exception.
+        """
+        if (self._local._loop is None and
+                not self._local._set_called and
+                threading.current_thread() is threading.main_thread()):
+            stacklevel = 2
+            try:
+                f = sys._getframe(1)
+            except AttributeError:
+                pass
+            else:
+                # Move up the call stack so that the warning is attached
+                # to the line outside asyncio itself.
+                while f:
+                    module = f.f_globals.get('__name__')
+                    if not (module == 'asyncio' or module.startswith('asyncio.')):
+                        break
+                    f = f.f_back
+                    stacklevel += 1
+            import warnings
+            warnings.warn('There is no current event loop',
+                          DeprecationWarning, stacklevel=stacklevel)
+            self.set_event_loop(self.new_event_loop())
+
+        if self._local._loop is None:
+            raise RuntimeError('There is no current event loop in thread %r.'
+                               % threading.current_thread().name)
+
+        return self._local._loop
+
+    def set_event_loop(self, loop):
+        """Set the event loop."""
+        self._local._set_called = True
+        if loop is not None and not isinstance(loop, AbstractEventLoop):
+            raise TypeError(f"loop must be an instance of AbstractEventLoop or None, not '{type(loop).__name__}'")
+        self._local._loop = loop
+
+    def new_event_loop(self):
+        """Create a new event loop.
+
+        You must call set_event_loop() to make this the current event
+        loop.
+        """
+        return self._loop_factory()
+
+
+# Event loop policy.  The policy itself is always global, even if the
+# policy's rules say that there is an event loop per thread (or other
+# notion of context).  The default policy is installed by the first
+# call to get_event_loop_policy().
+_event_loop_policy = None
+
+# Lock for protecting the on-the-fly creation of the event loop policy.
+_lock = threading.Lock()
+
+
+# A TLS for the running event loop, used by _get_running_loop.
+class _RunningLoop(threading.local):
+    loop_pid = (None, None)
+
+
+_running_loop = _RunningLoop()
+
+
+def get_running_loop():
+    """Return the running event loop.  Raise a RuntimeError if there is none.
+
+    This function is thread-specific.
+    """
+    # NOTE: this function is implemented in C (see _asynciomodule.c)
+    loop = _get_running_loop()
+    if loop is None:
+        raise RuntimeError('no running event loop')
+    return loop
+
+
+def _get_running_loop():
+    """Return the running event loop or None.
+
+    This is a low-level function intended to be used by event loops.
+    This function is thread-specific.
+    """
+    # NOTE: this function is implemented in C (see _asynciomodule.c)
+    running_loop, pid = _running_loop.loop_pid
+    if running_loop is not None and pid == os.getpid():
+        return running_loop
+
+
+def _set_running_loop(loop):
+    """Set the running event loop.
+
+    This is a low-level function intended to be used by event loops.
+    This function is thread-specific.
+    """
+    # NOTE: this function is implemented in C (see _asynciomodule.c)
+    _running_loop.loop_pid = (loop, os.getpid())
+
+
+def _init_event_loop_policy():
+    global _event_loop_policy
+    with _lock:
+        if _event_loop_policy is None:  # pragma: no branch
+            from . import DefaultEventLoopPolicy
+            _event_loop_policy = DefaultEventLoopPolicy()
+
+
+def get_event_loop_policy():
+    """Get the current event loop policy."""
+    if _event_loop_policy is None:
+        _init_event_loop_policy()
+    return _event_loop_policy
+
+
+def set_event_loop_policy(policy):
+    """Set the current event loop policy.
+
+    If policy is None, the default policy is restored."""
+    global _event_loop_policy
+    if policy is not None and not isinstance(policy, AbstractEventLoopPolicy):
+        raise TypeError(f"policy must be an instance of AbstractEventLoopPolicy or None, not '{type(policy).__name__}'")
+    _event_loop_policy = policy
+
+
+def get_event_loop():
+    """Return an asyncio event loop.
+
+    When called from a coroutine or a callback (e.g. scheduled with call_soon
+    or similar API), this function will always return the running event loop.
+
+    If there is no running event loop set, the function will return
+    the result of `get_event_loop_policy().get_event_loop()` call.
+    """
+    # NOTE: this function is implemented in C (see _asynciomodule.c)
+    current_loop = _get_running_loop()
+    if current_loop is not None:
+        return current_loop
+    return get_event_loop_policy().get_event_loop()
+
+
+def set_event_loop(loop):
+    """Equivalent to calling get_event_loop_policy().set_event_loop(loop)."""
+    get_event_loop_policy().set_event_loop(loop)
+
+
+def new_event_loop():
+    """Equivalent to calling get_event_loop_policy().new_event_loop()."""
+    return get_event_loop_policy().new_event_loop()
+
+
+def get_child_watcher():
+    """Equivalent to calling get_event_loop_policy().get_child_watcher()."""
+    return get_event_loop_policy().get_child_watcher()
+
+
+def set_child_watcher(watcher):
+    """Equivalent to calling
+    get_event_loop_policy().set_child_watcher(watcher)."""
+    return get_event_loop_policy().set_child_watcher(watcher)
+
+
+# Alias pure-Python implementations for testing purposes.
+_py__get_running_loop = _get_running_loop
+_py__set_running_loop = _set_running_loop
+_py_get_running_loop = get_running_loop
+_py_get_event_loop = get_event_loop
+
+
+try:
+    # get_event_loop() is one of the most frequently called
+    # functions in asyncio.  Pure Python implementation is
+    # about 4 times slower than C-accelerated.
+    from _asyncio import (_get_running_loop, _set_running_loop,
+                          get_running_loop, get_event_loop)
+except ImportError:
+    pass
+else:
+    # Alias C implementations for testing purposes.
+    _c__get_running_loop = _get_running_loop
+    _c__set_running_loop = _set_running_loop
+    _c_get_running_loop = get_running_loop
+    _c_get_event_loop = get_event_loop
+
+
+if hasattr(os, 'fork'):
+    def on_fork():
+        # Reset the loop and wakeupfd in the forked child process.
+        if _event_loop_policy is not None:
+            _event_loop_policy._local = BaseDefaultEventLoopPolicy._Local()
+        _set_running_loop(None)
+        signal.set_wakeup_fd(-1)
+
+    os.register_at_fork(after_in_child=on_fork)

Dependencies/Python/Lib/asyncio/exceptions.py

@@ -0,0 +1,62 @@
+"""asyncio exceptions."""
+
+
+__all__ = ('BrokenBarrierError',
+           'CancelledError', 'InvalidStateError', 'TimeoutError',
+           'IncompleteReadError', 'LimitOverrunError',
+           'SendfileNotAvailableError')
+
+
+class CancelledError(BaseException):
+    """The Future or Task was cancelled."""
+
+
+TimeoutError = TimeoutError  # make local alias for the standard exception
+
+
+class InvalidStateError(Exception):
+    """The operation is not allowed in this state."""
+
+
+class SendfileNotAvailableError(RuntimeError):
+    """Sendfile syscall is not available.
+
+    Raised if OS does not support sendfile syscall for given socket or
+    file type.
+    """
+
+
+class IncompleteReadError(EOFError):
+    """
+    Incomplete read error. Attributes:
+
+    - partial: read bytes string before the end of stream was reached
+    - expected: total number of expected bytes (or None if unknown)
+    """
+    def __init__(self, partial, expected):
+        r_expected = 'undefined' if expected is None else repr(expected)
+        super().__init__(f'{len(partial)} bytes read on a total of '
+                         f'{r_expected} expected bytes')
+        self.partial = partial
+        self.expected = expected
+
+    def __reduce__(self):
+        return type(self), (self.partial, self.expected)
+
+
+class LimitOverrunError(Exception):
+    """Reached the buffer limit while looking for a separator.
+
+    Attributes:
+    - consumed: total number of to be consumed bytes.
+    """
+    def __init__(self, message, consumed):
+        super().__init__(message)
+        self.consumed = consumed
+
+    def __reduce__(self):
+        return type(self), (self.args[0], self.consumed)
+
+
+class BrokenBarrierError(RuntimeError):
+    """Barrier is broken by barrier.abort() call."""

Dependencies/Python/Lib/asyncio/format_helpers.py

@@ -0,0 +1,84 @@
+import functools
+import inspect
+import reprlib
+import sys
+import traceback
+
+from . import constants
+
+
+def _get_function_source(func):
+    func = inspect.unwrap(func)
+    if inspect.isfunction(func):
+        code = func.__code__
+        return (code.co_filename, code.co_firstlineno)
+    if isinstance(func, functools.partial):
+        return _get_function_source(func.func)
+    if isinstance(func, functools.partialmethod):
+        return _get_function_source(func.func)
+    return None
+
+
+def _format_callback_source(func, args, *, debug=False):
+    func_repr = _format_callback(func, args, None, debug=debug)
+    source = _get_function_source(func)
+    if source:
+        func_repr += f' at {source[0]}:{source[1]}'
+    return func_repr
+
+
+def _format_args_and_kwargs(args, kwargs, *, debug=False):
+    """Format function arguments and keyword arguments.
+
+    Special case for a single parameter: ('hello',) is formatted as ('hello').
+
+    Note that this function only returns argument details when
+    debug=True is specified, as arguments may contain sensitive
+    information.
+    """
+    if not debug:
+        return '()'
+
+    # use reprlib to limit the length of the output
+    items = []
+    if args:
+        items.extend(reprlib.repr(arg) for arg in args)
+    if kwargs:
+        items.extend(f'{k}={reprlib.repr(v)}' for k, v in kwargs.items())
+    return '({})'.format(', '.join(items))
+
+
+def _format_callback(func, args, kwargs, *, debug=False, suffix=''):
+    if isinstance(func, functools.partial):
+        suffix = _format_args_and_kwargs(args, kwargs, debug=debug) + suffix
+        return _format_callback(func.func, func.args, func.keywords,
+                                debug=debug, suffix=suffix)
+
+    if hasattr(func, '__qualname__') and func.__qualname__:
+        func_repr = func.__qualname__
+    elif hasattr(func, '__name__') and func.__name__:
+        func_repr = func.__name__
+    else:
+        func_repr = repr(func)
+
+    func_repr += _format_args_and_kwargs(args, kwargs, debug=debug)
+    if suffix:
+        func_repr += suffix
+    return func_repr
+
+
+def extract_stack(f=None, limit=None):
+    """Replacement for traceback.extract_stack() that only does the
+    necessary work for asyncio debug mode.
+    """
+    if f is None:
+        f = sys._getframe().f_back
+    if limit is None:
+        # Limit the amount of work to a reasonable amount, as extract_stack()
+        # can be called for each coroutine and future in debug mode.
+        limit = constants.DEBUG_STACK_DEPTH
+    stack = traceback.StackSummary.extract(traceback.walk_stack(f),
+                                           limit=limit,
+                                           lookup_lines=False)
+    stack.reverse()
+    return stack

Dependencies/Python/Lib/asyncio/futures.py

@@ -0,0 +1,425 @@
+"""A Future class similar to the one in PEP 3148."""
+
+__all__ = (
+    'Future', 'wrap_future', 'isfuture',
+)
+
+import concurrent.futures
+import contextvars
+import logging
+import sys
+from types import GenericAlias
+
+from . import base_futures
+from . import events
+from . import exceptions
+from . import format_helpers
+
+
+isfuture = base_futures.isfuture
+
+
+_PENDING = base_futures._PENDING
+_CANCELLED = base_futures._CANCELLED
+_FINISHED = base_futures._FINISHED
+
+
+STACK_DEBUG = logging.DEBUG - 1  # heavy-duty debugging
+
+
+class Future:
+    """This class is *almost* compatible with concurrent.futures.Future.
+
+    Differences:
+
+    - This class is not thread-safe.
+
+    - result() and exception() do not take a timeout argument and
+      raise an exception when the future isn't done yet.
+
+    - Callbacks registered with add_done_callback() are always called
+      via the event loop's call_soon().
+
+    - This class is not compatible with the wait() and as_completed()
+      methods in the concurrent.futures package.
+
+    (In Python 3.4 or later we may be able to unify the implementations.)
+    """
+
+    # Class variables serving as defaults for instance variables.
+    _state = _PENDING
+    _result = None
+    _exception = None
+    _loop = None
+    _source_traceback = None
+    _cancel_message = None
+    # A saved CancelledError for later chaining as an exception context.
+    _cancelled_exc = None
+
+    # This field is used for a dual purpose:
+    # - Its presence is a marker to declare that a class implements
+    #   the Future protocol (i.e. is intended to be duck-type compatible).
+    #   The value must also be not-None, to enable a subclass to declare
+    #   that it is not compatible by setting this to None.
+    # - It is set by __iter__() below so that Task._step() can tell
+    #   the difference between
+    #   `await Future()` or`yield from Future()` (correct) vs.
+    #   `yield Future()` (incorrect).
+    _asyncio_future_blocking = False
+
+    __log_traceback = False
+
+    def __init__(self, *, loop=None):
+        """Initialize the future.
+
+        The optional event_loop argument allows explicitly setting the event
+        loop object used by the future. If it's not provided, the future uses
+        the default event loop.
+        """
+        if loop is None:
+            self._loop = events.get_event_loop()
+        else:
+            self._loop = loop
+        self._callbacks = []
+        if self._loop.get_debug():
+            self._source_traceback = format_helpers.extract_stack(
+                sys._getframe(1))
+
+    def __repr__(self):
+        return base_futures._future_repr(self)
+
+    def __del__(self):
+        if not self.__log_traceback:
+            # set_exception() was not called, or result() or exception()
+            # has consumed the exception
+            return
+        exc = self._exception
+        context = {
+            'message':
+                f'{self.__class__.__name__} exception was never retrieved',
+            'exception': exc,
+            'future': self,
+        }
+        if self._source_traceback:
+            context['source_traceback'] = self._source_traceback
+        self._loop.call_exception_handler(context)
+
+    __class_getitem__ = classmethod(GenericAlias)
+
+    @property
+    def _log_traceback(self):
+        return self.__log_traceback
+
+    @_log_traceback.setter
+    def _log_traceback(self, val):
+        if val:
+            raise ValueError('_log_traceback can only be set to False')
+        self.__log_traceback = False
+
+    def get_loop(self):
+        """Return the event loop the Future is bound to."""
+        loop = self._loop
+        if loop is None:
+            raise RuntimeError("Future object is not initialized.")
+        return loop
+
+    def _make_cancelled_error(self):
+        """Create the CancelledError to raise if the Future is cancelled.
+
+        This should only be called once when handling a cancellation since
+        it erases the saved context exception value.
+        """
+        if self._cancelled_exc is not None:
+            exc = self._cancelled_exc
+            self._cancelled_exc = None
+            return exc
+
+        if self._cancel_message is None:
+            exc = exceptions.CancelledError()
+        else:
+            exc = exceptions.CancelledError(self._cancel_message)
+        return exc
+
+    def cancel(self, msg=None):
+        """Cancel the future and schedule callbacks.
+
+        If the future is already done or cancelled, return False.  Otherwise,
+        change the future's state to cancelled, schedule the callbacks and
+        return True.
+        """
+        self.__log_traceback = False
+        if self._state != _PENDING:
+            return False
+        self._state = _CANCELLED
+        self._cancel_message = msg
+        self.__schedule_callbacks()
+        return True
+
+    def __schedule_callbacks(self):
+        """Internal: Ask the event loop to call all callbacks.
+
+        The callbacks are scheduled to be called as soon as possible. Also
+        clears the callback list.
+        """
+        callbacks = self._callbacks[:]
+        if not callbacks:
+            return
+
+        self._callbacks[:] = []
+        for callback, ctx in callbacks:
+            self._loop.call_soon(callback, self, context=ctx)
+
+    def cancelled(self):
+        """Return True if the future was cancelled."""
+        return self._state == _CANCELLED
+
+    # Don't implement running(); see http://bugs.python.org/issue18699
+
+    def done(self):
+        """Return True if the future is done.
+
+        Done means either that a result / exception are available, or that the
+        future was cancelled.
+        """
+        return self._state != _PENDING
+
+    def result(self):
+        """Return the result this future represents.
+
+        If the future has been cancelled, raises CancelledError.  If the
+        future's result isn't yet available, raises InvalidStateError.  If
+        the future is done and has an exception set, this exception is raised.
+        """
+        if self._state == _CANCELLED:
+            raise self._make_cancelled_error()
+        if self._state != _FINISHED:
+            raise exceptions.InvalidStateError('Result is not ready.')
+        self.__log_traceback = False
+        if self._exception is not None:
+            raise self._exception.with_traceback(self._exception_tb)
+        return self._result
+
+    def exception(self):
+        """Return the exception that was set on this future.
+
+        The exception (or None if no exception was set) is returned only if
+        the future is done.  If the future has been cancelled, raises
+        CancelledError.  If the future isn't done yet, raises
+        InvalidStateError.
+        """
+        if self._state == _CANCELLED:
+            raise self._make_cancelled_error()
+        if self._state != _FINISHED:
+            raise exceptions.InvalidStateError('Exception is not set.')
+        self.__log_traceback = False
+        return self._exception
+
+    def add_done_callback(self, fn, *, context=None):
+        """Add a callback to be run when the future becomes done.
+
+        The callback is called with a single argument - the future object. If
+        the future is already done when this is called, the callback is
+        scheduled with call_soon.
+        """
+        if self._state != _PENDING:
+            self._loop.call_soon(fn, self, context=context)
+        else:
+            if context is None:
+                context = contextvars.copy_context()
+            self._callbacks.append((fn, context))
+
+    # New method not in PEP 3148.
+
+    def remove_done_callback(self, fn):
+        """Remove all instances of a callback from the "call when done" list.
+
+        Returns the number of callbacks removed.
+        """
+        filtered_callbacks = [(f, ctx)
+                              for (f, ctx) in self._callbacks
+                              if f != fn]
+        removed_count = len(self._callbacks) - len(filtered_callbacks)
+        if removed_count:
+            self._callbacks[:] = filtered_callbacks
+        return removed_count
+
+    # So-called internal methods (note: no set_running_or_notify_cancel()).
+
+    def set_result(self, result):
+        """Mark the future done and set its result.
+
+        If the future is already done when this method is called, raises
+        InvalidStateError.
+        """
+        if self._state != _PENDING:
+            raise exceptions.InvalidStateError(f'{self._state}: {self!r}')
+        self._result = result
+        self._state = _FINISHED
+        self.__schedule_callbacks()
+
+    def set_exception(self, exception):
+        """Mark the future done and set an exception.
+
+        If the future is already done when this method is called, raises
+        InvalidStateError.
+        """
+        if self._state != _PENDING:
+            raise exceptions.InvalidStateError(f'{self._state}: {self!r}')
+        if isinstance(exception, type):
+            exception = exception()
+        if isinstance(exception, StopIteration):
+            new_exc = RuntimeError("StopIteration interacts badly with "
+                                   "generators and cannot be raised into a "
+                                   "Future")
+            new_exc.__cause__ = exception
+            new_exc.__context__ = exception
+            exception = new_exc
+        self._exception = exception
+        self._exception_tb = exception.__traceback__
+        self._state = _FINISHED
+        self.__schedule_callbacks()
+        self.__log_traceback = True
+
+    def __await__(self):
+        if not self.done():
+            self._asyncio_future_blocking = True
+            yield self  # This tells Task to wait for completion.
+        if not self.done():
+            raise RuntimeError("await wasn't used with future")
+        return self.result()  # May raise too.
+
+    __iter__ = __await__  # make compatible with 'yield from'.
+
+
+# Needed for testing purposes.
+_PyFuture = Future
+
+
+def _get_loop(fut):
+    # Tries to call Future.get_loop() if it's available.
+    # Otherwise fallbacks to using the old '_loop' property.
+    try:
+        get_loop = fut.get_loop
+    except AttributeError:
+        pass
+    else:
+        return get_loop()
+    return fut._loop
+
+
+def _set_result_unless_cancelled(fut, result):
+    """Helper setting the result only if the future was not cancelled."""
+    if fut.cancelled():
+        return
+    fut.set_result(result)
+
+
+def _convert_future_exc(exc):
+    exc_class = type(exc)
+    if exc_class is concurrent.futures.CancelledError:
+        return exceptions.CancelledError(*exc.args).with_traceback(exc.__traceback__)
+    elif exc_class is concurrent.futures.InvalidStateError:
+        return exceptions.InvalidStateError(*exc.args).with_traceback(exc.__traceback__)
+    else:
+        return exc
+
+
+def _set_concurrent_future_state(concurrent, source):
+    """Copy state from a future to a concurrent.futures.Future."""
+    assert source.done()
+    if source.cancelled():
+        concurrent.cancel()
+    if not concurrent.set_running_or_notify_cancel():
+        return
+    exception = source.exception()
+    if exception is not None:
+        concurrent.set_exception(_convert_future_exc(exception))
+    else:
+        result = source.result()
+        concurrent.set_result(result)
+
+
+def _copy_future_state(source, dest):
+    """Internal helper to copy state from another Future.
+
+    The other Future may be a concurrent.futures.Future.
+    """
+    assert source.done()
+    if dest.cancelled():
+        return
+    assert not dest.done()
+    if source.cancelled():
+        dest.cancel()
+    else:
+        exception = source.exception()
+        if exception is not None:
+            dest.set_exception(_convert_future_exc(exception))
+        else:
+            result = source.result()
+            dest.set_result(result)
+
+
+def _chain_future(source, destination):
+    """Chain two futures so that when one completes, so does the other.
+
+    The result (or exception) of source will be copied to destination.
+    If destination is cancelled, source gets cancelled too.
+    Compatible with both asyncio.Future and concurrent.futures.Future.
+    """
+    if not isfuture(source) and not isinstance(source,
+                                               concurrent.futures.Future):
+        raise TypeError('A future is required for source argument')
+    if not isfuture(destination) and not isinstance(destination,
+                                                    concurrent.futures.Future):
+        raise TypeError('A future is required for destination argument')
+    source_loop = _get_loop(source) if isfuture(source) else None
+    dest_loop = _get_loop(destination) if isfuture(destination) else None
+
+    def _set_state(future, other):
+        if isfuture(future):
+            _copy_future_state(other, future)
+        else:
+            _set_concurrent_future_state(future, other)
+
+    def _call_check_cancel(destination):
+        if destination.cancelled():
+            if source_loop is None or source_loop is dest_loop:
+                source.cancel()
+            else:
+                source_loop.call_soon_threadsafe(source.cancel)
+
+    def _call_set_state(source):
+        if (destination.cancelled() and
+                dest_loop is not None and dest_loop.is_closed()):
+            return
+        if dest_loop is None or dest_loop is source_loop:
+            _set_state(destination, source)
+        else:
+            if dest_loop.is_closed():
+                return
+            dest_loop.call_soon_threadsafe(_set_state, destination, source)
+
+    destination.add_done_callback(_call_check_cancel)
+    source.add_done_callback(_call_set_state)
+
+
+def wrap_future(future, *, loop=None):
+    """Wrap concurrent.futures.Future object."""
+    if isfuture(future):
+        return future
+    assert isinstance(future, concurrent.futures.Future), \
+        f'concurrent.futures.Future is expected, got {future!r}'
+    if loop is None:
+        loop = events.get_event_loop()
+    new_future = loop.create_future()
+    _chain_future(future, new_future)
+    return new_future
+
+
+try:
+    import _asyncio
+except ImportError:
+    pass
+else:
+    # _CFuture is needed for tests.
+    Future = _CFuture = _asyncio.Future

Dependencies/Python/Lib/asyncio/locks.py

@@ -0,0 +1,617 @@
+"""Synchronization primitives."""
+
+__all__ = ('Lock', 'Event', 'Condition', 'Semaphore',
+           'BoundedSemaphore', 'Barrier')
+
+import collections
+import enum
+
+from . import exceptions
+from . import mixins
+
+class _ContextManagerMixin:
+    async def __aenter__(self):
+        await self.acquire()
+        # We have no use for the "as ..."  clause in the with
+        # statement for locks.
+        return None
+
+    async def __aexit__(self, exc_type, exc, tb):
+        self.release()
+
+
+class Lock(_ContextManagerMixin, mixins._LoopBoundMixin):
+    """Primitive lock objects.
+
+    A primitive lock is a synchronization primitive that is not owned
+    by a particular task when locked.  A primitive lock is in one
+    of two states, 'locked' or 'unlocked'.
+
+    It is created in the unlocked state.  It has two basic methods,
+    acquire() and release().  When the state is unlocked, acquire()
+    changes the state to locked and returns immediately.  When the
+    state is locked, acquire() blocks until a call to release() in
+    another task changes it to unlocked, then the acquire() call
+    resets it to locked and returns.  The release() method should only
+    be called in the locked state; it changes the state to unlocked
+    and returns immediately.  If an attempt is made to release an
+    unlocked lock, a RuntimeError will be raised.
+
+    When more than one task is blocked in acquire() waiting for
+    the state to turn to unlocked, only one task proceeds when a
+    release() call resets the state to unlocked; successive release()
+    calls will unblock tasks in FIFO order.
+
+    Locks also support the asynchronous context management protocol.
+    'async with lock' statement should be used.
+
+    Usage:
+
+        lock = Lock()
+        ...
+        await lock.acquire()
+        try:
+            ...
+        finally:
+            lock.release()
+
+    Context manager usage:
+
+        lock = Lock()
+        ...
+        async with lock:
+             ...
+
+    Lock objects can be tested for locking state:
+
+        if not lock.locked():
+           await lock.acquire()
+        else:
+           # lock is acquired
+           ...
+
+    """
+
+    def __init__(self):
+        self._waiters = None
+        self._locked = False
+
+    def __repr__(self):
+        res = super().__repr__()
+        extra = 'locked' if self._locked else 'unlocked'
+        if self._waiters:
+            extra = f'{extra}, waiters:{len(self._waiters)}'
+        return f'<{res[1:-1]} [{extra}]>'
+
+    def locked(self):
+        """Return True if lock is acquired."""
+        return self._locked
+
+    async def acquire(self):
+        """Acquire a lock.
+
+        This method blocks until the lock is unlocked, then sets it to
+        locked and returns True.
+        """
+        # Implement fair scheduling, where thread always waits
+        # its turn. Jumping the queue if all are cancelled is an optimization.
+        if (not self._locked and (self._waiters is None or
+                all(w.cancelled() for w in self._waiters))):
+            self._locked = True
+            return True
+
+        if self._waiters is None:
+            self._waiters = collections.deque()
+        fut = self._get_loop().create_future()
+        self._waiters.append(fut)
+
+        try:
+            try:
+                await fut
+            finally:
+                self._waiters.remove(fut)
+        except exceptions.CancelledError:
+            # Currently the only exception designed be able to occur here.
+
+            # Ensure the lock invariant: If lock is not claimed (or about
+            # to be claimed by us) and there is a Task in waiters,
+            # ensure that the Task at the head will run.
+            if not self._locked:
+                self._wake_up_first()
+            raise
+
+        # assert self._locked is False
+        self._locked = True
+        return True
+
+    def release(self):
+        """Release a lock.
+
+        When the lock is locked, reset it to unlocked, and return.
+        If any other tasks are blocked waiting for the lock to become
+        unlocked, allow exactly one of them to proceed.
+
+        When invoked on an unlocked lock, a RuntimeError is raised.
+
+        There is no return value.
+        """
+        if self._locked:
+            self._locked = False
+            self._wake_up_first()
+        else:
+            raise RuntimeError('Lock is not acquired.')
+
+    def _wake_up_first(self):
+        """Ensure that the first waiter will wake up."""
+        if not self._waiters:
+            return
+        try:
+            fut = next(iter(self._waiters))
+        except StopIteration:
+            return
+
+        # .done() means that the waiter is already set to wake up.
+        if not fut.done():
+            fut.set_result(True)
+
+
+class Event(mixins._LoopBoundMixin):
+    """Asynchronous equivalent to threading.Event.
+
+    Class implementing event objects. An event manages a flag that can be set
+    to true with the set() method and reset to false with the clear() method.
+    The wait() method blocks until the flag is true. The flag is initially
+    false.
+    """
+
+    def __init__(self):
+        self._waiters = collections.deque()
+        self._value = False
+
+    def __repr__(self):
+        res = super().__repr__()
+        extra = 'set' if self._value else 'unset'
+        if self._waiters:
+            extra = f'{extra}, waiters:{len(self._waiters)}'
+        return f'<{res[1:-1]} [{extra}]>'
+
+    def is_set(self):
+        """Return True if and only if the internal flag is true."""
+        return self._value
+
+    def set(self):
+        """Set the internal flag to true. All tasks waiting for it to
+        become true are awakened. Tasks that call wait() once the flag is
+        true will not block at all.
+        """
+        if not self._value:
+            self._value = True
+
+            for fut in self._waiters:
+                if not fut.done():
+                    fut.set_result(True)
+
+    def clear(self):
+        """Reset the internal flag to false. Subsequently, tasks calling
+        wait() will block until set() is called to set the internal flag
+        to true again."""
+        self._value = False
+
+    async def wait(self):
+        """Block until the internal flag is true.
+
+        If the internal flag is true on entry, return True
+        immediately.  Otherwise, block until another task calls
+        set() to set the flag to true, then return True.
+        """
+        if self._value:
+            return True
+
+        fut = self._get_loop().create_future()
+        self._waiters.append(fut)
+        try:
+            await fut
+            return True
+        finally:
+            self._waiters.remove(fut)
+
+
+class Condition(_ContextManagerMixin, mixins._LoopBoundMixin):
+    """Asynchronous equivalent to threading.Condition.
+
+    This class implements condition variable objects. A condition variable
+    allows one or more tasks to wait until they are notified by another
+    task.
+
+    A new Lock object is created and used as the underlying lock.
+    """
+
+    def __init__(self, lock=None):
+        if lock is None:
+            lock = Lock()
+
+        self._lock = lock
+        # Export the lock's locked(), acquire() and release() methods.
+        self.locked = lock.locked
+        self.acquire = lock.acquire
+        self.release = lock.release
+
+        self._waiters = collections.deque()
+
+    def __repr__(self):
+        res = super().__repr__()
+        extra = 'locked' if self.locked() else 'unlocked'
+        if self._waiters:
+            extra = f'{extra}, waiters:{len(self._waiters)}'
+        return f'<{res[1:-1]} [{extra}]>'
+
+    async def wait(self):
+        """Wait until notified.
+
+        If the calling task has not acquired the lock when this
+        method is called, a RuntimeError is raised.
+
+        This method releases the underlying lock, and then blocks
+        until it is awakened by a notify() or notify_all() call for
+        the same condition variable in another task.  Once
+        awakened, it re-acquires the lock and returns True.
+
+        This method may return spuriously,
+        which is why the caller should always
+        re-check the state and be prepared to wait() again.
+        """
+        if not self.locked():
+            raise RuntimeError('cannot wait on un-acquired lock')
+
+        fut = self._get_loop().create_future()
+        self.release()
+        try:
+            try:
+                self._waiters.append(fut)
+                try:
+                    await fut
+                    return True
+                finally:
+                    self._waiters.remove(fut)
+
+            finally:
+                # Must re-acquire lock even if wait is cancelled.
+                # We only catch CancelledError here, since we don't want any
+                # other (fatal) errors with the future to cause us to spin.
+                err = None
+                while True:
+                    try:
+                        await self.acquire()
+                        break
+                    except exceptions.CancelledError as e:
+                        err = e
+
+                if err is not None:
+                    try:
+                        raise err  # Re-raise most recent exception instance.
+                    finally:
+                        err = None  # Break reference cycles.
+        except BaseException:
+            # Any error raised out of here _may_ have occurred after this Task
+            # believed to have been successfully notified.
+            # Make sure to notify another Task instead.  This may result
+            # in a "spurious wakeup", which is allowed as part of the
+            # Condition Variable protocol.
+            self._notify(1)
+            raise
+
+    async def wait_for(self, predicate):
+        """Wait until a predicate becomes true.
+
+        The predicate should be a callable whose result will be
+        interpreted as a boolean value.  The method will repeatedly
+        wait() until it evaluates to true.  The final predicate value is
+        the return value.
+        """
+        result = predicate()
+        while not result:
+            await self.wait()
+            result = predicate()
+        return result
+
+    def notify(self, n=1):
+        """By default, wake up one task waiting on this condition, if any.
+        If the calling task has not acquired the lock when this method
+        is called, a RuntimeError is raised.
+
+        This method wakes up n of the tasks waiting for the condition
+         variable; if fewer than n are waiting, they are all awoken.
+
+        Note: an awakened task does not actually return from its
+        wait() call until it can reacquire the lock. Since notify() does
+        not release the lock, its caller should.
+        """
+        if not self.locked():
+            raise RuntimeError('cannot notify on un-acquired lock')
+        self._notify(n)
+
+    def _notify(self, n):
+        idx = 0
+        for fut in self._waiters:
+            if idx >= n:
+                break
+
+            if not fut.done():
+                idx += 1
+                fut.set_result(False)
+
+    def notify_all(self):
+        """Wake up all threads waiting on this condition. This method acts
+        like notify(), but wakes up all waiting threads instead of one. If the
+        calling thread has not acquired the lock when this method is called,
+        a RuntimeError is raised.
+        """
+        self.notify(len(self._waiters))
+
+
+class Semaphore(_ContextManagerMixin, mixins._LoopBoundMixin):
+    """A Semaphore implementation.
+
+    A semaphore manages an internal counter which is decremented by each
+    acquire() call and incremented by each release() call. The counter
+    can never go below zero; when acquire() finds that it is zero, it blocks,
+    waiting until some other thread calls release().
+
+    Semaphores also support the context management protocol.
+
+    The optional argument gives the initial value for the internal
+    counter; it defaults to 1. If the value given is less than 0,
+    ValueError is raised.
+    """
+
+    def __init__(self, value=1):
+        if value < 0:
+            raise ValueError("Semaphore initial value must be >= 0")
+        self._waiters = None
+        self._value = value
+
+    def __repr__(self):
+        res = super().__repr__()
+        extra = 'locked' if self.locked() else f'unlocked, value:{self._value}'
+        if self._waiters:
+            extra = f'{extra}, waiters:{len(self._waiters)}'
+        return f'<{res[1:-1]} [{extra}]>'
+
+    def locked(self):
+        """Returns True if semaphore cannot be acquired immediately."""
+        # Due to state, or FIFO rules (must allow others to run first).
+        return self._value == 0 or (
+            any(not w.cancelled() for w in (self._waiters or ())))
+
+    async def acquire(self):
+        """Acquire a semaphore.
+
+        If the internal counter is larger than zero on entry,
+        decrement it by one and return True immediately.  If it is
+        zero on entry, block, waiting until some other task has
+        called release() to make it larger than 0, and then return
+        True.
+        """
+        if not self.locked():
+            # Maintain FIFO, wait for others to start even if _value > 0.
+            self._value -= 1
+            return True
+
+        if self._waiters is None:
+            self._waiters = collections.deque()
+        fut = self._get_loop().create_future()
+        self._waiters.append(fut)
+
+        try:
+            try:
+                await fut
+            finally:
+                self._waiters.remove(fut)
+        except exceptions.CancelledError:
+            # Currently the only exception designed be able to occur here.
+            if fut.done() and not fut.cancelled():
+                # Our Future was successfully set to True via _wake_up_next(),
+                # but we are not about to successfully acquire(). Therefore we
+                # must undo the bookkeeping already done and attempt to wake
+                # up someone else.
+                self._value += 1
+            raise
+
+        finally:
+            # New waiters may have arrived but had to wait due to FIFO.
+            # Wake up as many as are allowed.
+            while self._value > 0:
+                if not self._wake_up_next():
+                    break  # There was no-one to wake up.
+        return True
+
+    def release(self):
+        """Release a semaphore, incrementing the internal counter by one.
+
+        When it was zero on entry and another task is waiting for it to
+        become larger than zero again, wake up that task.
+        """
+        self._value += 1
+        self._wake_up_next()
+
+    def _wake_up_next(self):
+        """Wake up the first waiter that isn't done."""
+        if not self._waiters:
+            return False
+
+        for fut in self._waiters:
+            if not fut.done():
+                self._value -= 1
+                fut.set_result(True)
+                # `fut` is now `done()` and not `cancelled()`.
+                return True
+        return False
+
+
+class BoundedSemaphore(Semaphore):
+    """A bounded semaphore implementation.
+
+    This raises ValueError in release() if it would increase the value
+    above the initial value.
+    """
+
+    def __init__(self, value=1):
+        self._bound_value = value
+        super().__init__(value)
+
+    def release(self):
+        if self._value >= self._bound_value:
+            raise ValueError('BoundedSemaphore released too many times')
+        super().release()
+
+
+
+class _BarrierState(enum.Enum):
+    FILLING = 'filling'
+    DRAINING = 'draining'
+    RESETTING = 'resetting'
+    BROKEN = 'broken'
+
+
+class Barrier(mixins._LoopBoundMixin):
+    """Asyncio equivalent to threading.Barrier
+
+    Implements a Barrier primitive.
+    Useful for synchronizing a fixed number of tasks at known synchronization
+    points. Tasks block on 'wait()' and are simultaneously awoken once they
+    have all made their call.
+    """
+
+    def __init__(self, parties):
+        """Create a barrier, initialised to 'parties' tasks."""
+        if parties < 1:
+            raise ValueError('parties must be >= 1')
+
+        self._cond = Condition() # notify all tasks when state changes
+
+        self._parties = parties
+        self._state = _BarrierState.FILLING
+        self._count = 0       # count tasks in Barrier
+
+    def __repr__(self):
+        res = super().__repr__()
+        extra = f'{self._state.value}'
+        if not self.broken:
+            extra += f', waiters:{self.n_waiting}/{self.parties}'
+        return f'<{res[1:-1]} [{extra}]>'
+
+    async def __aenter__(self):
+        # wait for the barrier reaches the parties number
+        # when start draining release and return index of waited task
+        return await self.wait()
+
+    async def __aexit__(self, *args):
+        pass
+
+    async def wait(self):
+        """Wait for the barrier.
+
+        When the specified number of tasks have started waiting, they are all
+        simultaneously awoken.
+        Returns an unique and individual index number from 0 to 'parties-1'.
+        """
+        async with self._cond:
+            await self._block() # Block while the barrier drains or resets.
+            try:
+                index = self._count
+                self._count += 1
+                if index + 1 == self._parties:
+                    # We release the barrier
+                    await self._release()
+                else:
+                    await self._wait()
+                return index
+            finally:
+                self._count -= 1
+                # Wake up any tasks waiting for barrier to drain.
+                self._exit()
+
+    async def _block(self):
+        # Block until the barrier is ready for us,
+        # or raise an exception if it is broken.
+        #
+        # It is draining or resetting, wait until done
+        # unless a CancelledError occurs
+        await self._cond.wait_for(
+            lambda: self._state not in (
+                _BarrierState.DRAINING, _BarrierState.RESETTING
+            )
+        )
+
+        # see if the barrier is in a broken state
+        if self._state is _BarrierState.BROKEN:
+            raise exceptions.BrokenBarrierError("Barrier aborted")
+
+    async def _release(self):
+        # Release the tasks waiting in the barrier.
+
+        # Enter draining state.
+        # Next waiting tasks will be blocked until the end of draining.
+        self._state = _BarrierState.DRAINING
+        self._cond.notify_all()
+
+    async def _wait(self):
+        # Wait in the barrier until we are released. Raise an exception
+        # if the barrier is reset or broken.
+
+        # wait for end of filling
+        # unless a CancelledError occurs
+        await self._cond.wait_for(lambda: self._state is not _BarrierState.FILLING)
+
+        if self._state in (_BarrierState.BROKEN, _BarrierState.RESETTING):
+            raise exceptions.BrokenBarrierError("Abort or reset of barrier")
+
+    def _exit(self):
+        # If we are the last tasks to exit the barrier, signal any tasks
+        # waiting for the barrier to drain.
+        if self._count == 0:
+            if self._state in (_BarrierState.RESETTING, _BarrierState.DRAINING):
+                self._state = _BarrierState.FILLING
+            self._cond.notify_all()
+
+    async def reset(self):
+        """Reset the barrier to the initial state.
+
+        Any tasks currently waiting will get the BrokenBarrier exception
+        raised.
+        """
+        async with self._cond:
+            if self._count > 0:
+                if self._state is not _BarrierState.RESETTING:
+                    #reset the barrier, waking up tasks
+                    self._state = _BarrierState.RESETTING
+            else:
+                self._state = _BarrierState.FILLING
+            self._cond.notify_all()
+
+    async def abort(self):
+        """Place the barrier into a 'broken' state.
+
+        Useful in case of error.  Any currently waiting tasks and tasks
+        attempting to 'wait()' will have BrokenBarrierError raised.
+        """
+        async with self._cond:
+            self._state = _BarrierState.BROKEN
+            self._cond.notify_all()
+
+    @property
+    def parties(self):
+        """Return the number of tasks required to trip the barrier."""
+        return self._parties
+
+    @property
+    def n_waiting(self):
+        """Return the number of tasks currently waiting at the barrier."""
+        if self._state is _BarrierState.FILLING:
+            return self._count
+        return 0
+
+    @property
+    def broken(self):
+        """Return True if the barrier is in a broken state."""
+        return self._state is _BarrierState.BROKEN

Dependencies/Python/Lib/asyncio/log.py

@@ -0,0 +1,7 @@
+"""Logging configuration."""
+
+import logging
+
+
+# Name the logger after the package.
+logger = logging.getLogger(__package__)

Dependencies/Python/Lib/asyncio/mixins.py

@@ -0,0 +1,21 @@
+"""Event loop mixins."""
+
+import threading
+from . import events
+
+_global_lock = threading.Lock()
+
+
+class _LoopBoundMixin:
+    _loop = None
+
+    def _get_loop(self):
+        loop = events._get_running_loop()
+
+        if self._loop is None:
+            with _global_lock:
+                if self._loop is None:
+                    self._loop = loop
+        if loop is not self._loop:
+            raise RuntimeError(f'{self!r} is bound to a different event loop')
+        return loop

Dependencies/Python/Lib/asyncio/proactor_events.py

@@ -0,0 +1,894 @@
+"""Event loop using a proactor and related classes.
+
+A proactor is a "notify-on-completion" multiplexer.  Currently a
+proactor is only implemented on Windows with IOCP.
+"""
+
+__all__ = 'BaseProactorEventLoop',
+
+import io
+import os
+import socket
+import warnings
+import signal
+import threading
+import collections
+
+from . import base_events
+from . import constants
+from . import futures
+from . import exceptions
+from . import protocols
+from . import sslproto
+from . import transports
+from . import trsock
+from .log import logger
+
+
+def _set_socket_extra(transport, sock):
+    transport._extra['socket'] = trsock.TransportSocket(sock)
+
+    try:
+        transport._extra['sockname'] = sock.getsockname()
+    except socket.error:
+        if transport._loop.get_debug():
+            logger.warning(
+                "getsockname() failed on %r", sock, exc_info=True)
+
+    if 'peername' not in transport._extra:
+        try:
+            transport._extra['peername'] = sock.getpeername()
+        except socket.error:
+            # UDP sockets may not have a peer name
+            transport._extra['peername'] = None
+
+
+class _ProactorBasePipeTransport(transports._FlowControlMixin,
+                                 transports.BaseTransport):
+    """Base class for pipe and socket transports."""
+
+    def __init__(self, loop, sock, protocol, waiter=None,
+                 extra=None, server=None):
+        super().__init__(extra, loop)
+        self._set_extra(sock)
+        self._sock = sock
+        self.set_protocol(protocol)
+        self._server = server
+        self._buffer = None  # None or bytearray.
+        self._read_fut = None
+        self._write_fut = None
+        self._pending_write = 0
+        self._conn_lost = 0
+        self._closing = False  # Set when close() called.
+        self._called_connection_lost = False
+        self._eof_written = False
+        if self._server is not None:
+            self._server._attach(self)
+        self._loop.call_soon(self._protocol.connection_made, self)
+        if waiter is not None:
+            # only wake up the waiter when connection_made() has been called
+            self._loop.call_soon(futures._set_result_unless_cancelled,
+                                 waiter, None)
+
+    def __repr__(self):
+        info = [self.__class__.__name__]
+        if self._sock is None:
+            info.append('closed')
+        elif self._closing:
+            info.append('closing')
+        if self._sock is not None:
+            info.append(f'fd={self._sock.fileno()}')
+        if self._read_fut is not None:
+            info.append(f'read={self._read_fut!r}')
+        if self._write_fut is not None:
+            info.append(f'write={self._write_fut!r}')
+        if self._buffer:
+            info.append(f'write_bufsize={len(self._buffer)}')
+        if self._eof_written:
+            info.append('EOF written')
+        return '<{}>'.format(' '.join(info))
+
+    def _set_extra(self, sock):
+        self._extra['pipe'] = sock
+
+    def set_protocol(self, protocol):
+        self._protocol = protocol
+
+    def get_protocol(self):
+        return self._protocol
+
+    def is_closing(self):
+        return self._closing
+
+    def close(self):
+        if self._closing:
+            return
+        self._closing = True
+        self._conn_lost += 1
+        if not self._buffer and self._write_fut is None:
+            self._loop.call_soon(self._call_connection_lost, None)
+        if self._read_fut is not None:
+            self._read_fut.cancel()
+            self._read_fut = None
+
+    def __del__(self, _warn=warnings.warn):
+        if self._sock is not None:
+            _warn(f"unclosed transport {self!r}", ResourceWarning, source=self)
+            self._sock.close()
+
+    def _fatal_error(self, exc, message='Fatal error on pipe transport'):
+        try:
+            if isinstance(exc, OSError):
+                if self._loop.get_debug():
+                    logger.debug("%r: %s", self, message, exc_info=True)
+            else:
+                self._loop.call_exception_handler({
+                    'message': message,
+                    'exception': exc,
+                    'transport': self,
+                    'protocol': self._protocol,
+                })
+        finally:
+            self._force_close(exc)
+
+    def _force_close(self, exc):
+        if self._empty_waiter is not None and not self._empty_waiter.done():
+            if exc is None:
+                self._empty_waiter.set_result(None)
+            else:
+                self._empty_waiter.set_exception(exc)
+        if self._closing and self._called_connection_lost:
+            return
+        self._closing = True
+        self._conn_lost += 1
+        if self._write_fut:
+            self._write_fut.cancel()
+            self._write_fut = None
+        if self._read_fut:
+            self._read_fut.cancel()
+            self._read_fut = None
+        self._pending_write = 0
+        self._buffer = None
+        self._loop.call_soon(self._call_connection_lost, exc)
+
+    def _call_connection_lost(self, exc):
+        if self._called_connection_lost:
+            return
+        try:
+            self._protocol.connection_lost(exc)
+        finally:
+            # XXX If there is a pending overlapped read on the other
+            # end then it may fail with ERROR_NETNAME_DELETED if we
+            # just close our end.  First calling shutdown() seems to
+            # cure it, but maybe using DisconnectEx() would be better.
+            if hasattr(self._sock, 'shutdown') and self._sock.fileno() != -1:
+                self._sock.shutdown(socket.SHUT_RDWR)
+            self._sock.close()
+            self._sock = None
+            server = self._server
+            if server is not None:
+                server._detach(self)
+                self._server = None
+            self._called_connection_lost = True
+
+    def get_write_buffer_size(self):
+        size = self._pending_write
+        if self._buffer is not None:
+            size += len(self._buffer)
+        return size
+
+
+class _ProactorReadPipeTransport(_ProactorBasePipeTransport,
+                                 transports.ReadTransport):
+    """Transport for read pipes."""
+
+    def __init__(self, loop, sock, protocol, waiter=None,
+                 extra=None, server=None, buffer_size=65536):
+        self._pending_data_length = -1
+        self._paused = True
+        super().__init__(loop, sock, protocol, waiter, extra, server)
+
+        self._data = bytearray(buffer_size)
+        self._loop.call_soon(self._loop_reading)
+        self._paused = False
+
+    def is_reading(self):
+        return not self._paused and not self._closing
+
+    def pause_reading(self):
+        if self._closing or self._paused:
+            return
+        self._paused = True
+
+        # bpo-33694: Don't cancel self._read_fut because cancelling an
+        # overlapped WSASend() loss silently data with the current proactor
+        # implementation.
+        #
+        # If CancelIoEx() fails with ERROR_NOT_FOUND, it means that WSASend()
+        # completed (even if HasOverlappedIoCompleted() returns 0), but
+        # Overlapped.cancel() currently silently ignores the ERROR_NOT_FOUND
+        # error. Once the overlapped is ignored, the IOCP loop will ignores the
+        # completion I/O event and so not read the result of the overlapped
+        # WSARecv().
+
+        if self._loop.get_debug():
+            logger.debug("%r pauses reading", self)
+
+    def resume_reading(self):
+        if self._closing or not self._paused:
+            return
+
+        self._paused = False
+        if self._read_fut is None:
+            self._loop.call_soon(self._loop_reading, None)
+
+        length = self._pending_data_length
+        self._pending_data_length = -1
+        if length > -1:
+            # Call the protocol method after calling _loop_reading(),
+            # since the protocol can decide to pause reading again.
+            self._loop.call_soon(self._data_received, self._data[:length], length)
+
+        if self._loop.get_debug():
+            logger.debug("%r resumes reading", self)
+
+    def _eof_received(self):
+        if self._loop.get_debug():
+            logger.debug("%r received EOF", self)
+
+        try:
+            keep_open = self._protocol.eof_received()
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as exc:
+            self._fatal_error(
+                exc, 'Fatal error: protocol.eof_received() call failed.')
+            return
+
+        if not keep_open:
+            self.close()
+
+    def _data_received(self, data, length):
+        if self._paused:
+            # Don't call any protocol method while reading is paused.
+            # The protocol will be called on resume_reading().
+            assert self._pending_data_length == -1
+            self._pending_data_length = length
+            return
+
+        if length == 0:
+            self._eof_received()
+            return
+
+        if isinstance(self._protocol, protocols.BufferedProtocol):
+            try:
+                protocols._feed_data_to_buffered_proto(self._protocol, data)
+            except (SystemExit, KeyboardInterrupt):
+                raise
+            except BaseException as exc:
+                self._fatal_error(exc,
+                                  'Fatal error: protocol.buffer_updated() '
+                                  'call failed.')
+                return
+        else:
+            self._protocol.data_received(data)
+
+    def _loop_reading(self, fut=None):
+        length = -1
+        data = None
+        try:
+            if fut is not None:
+                assert self._read_fut is fut or (self._read_fut is None and
+                                                 self._closing)
+                self._read_fut = None
+                if fut.done():
+                    # deliver data later in "finally" clause
+                    length = fut.result()
+                    if length == 0:
+                        # we got end-of-file so no need to reschedule a new read
+                        return
+
+                    # It's a new slice so make it immutable so protocols upstream don't have problems
+                    data = bytes(memoryview(self._data)[:length])
+                else:
+                    # the future will be replaced by next proactor.recv call
+                    fut.cancel()
+
+            if self._closing:
+                # since close() has been called we ignore any read data
+                return
+
+            # bpo-33694: buffer_updated() has currently no fast path because of
+            # a data loss issue caused by overlapped WSASend() cancellation.
+
+            if not self._paused:
+                # reschedule a new read
+                self._read_fut = self._loop._proactor.recv_into(self._sock, self._data)
+        except ConnectionAbortedError as exc:
+            if not self._closing:
+                self._fatal_error(exc, 'Fatal read error on pipe transport')
+            elif self._loop.get_debug():
+                logger.debug("Read error on pipe transport while closing",
+                             exc_info=True)
+        except ConnectionResetError as exc:
+            self._force_close(exc)
+        except OSError as exc:
+            self._fatal_error(exc, 'Fatal read error on pipe transport')
+        except exceptions.CancelledError:
+            if not self._closing:
+                raise
+        else:
+            if not self._paused:
+                self._read_fut.add_done_callback(self._loop_reading)
+        finally:
+            if length > -1:
+                self._data_received(data, length)
+
+
+class _ProactorBaseWritePipeTransport(_ProactorBasePipeTransport,
+                                      transports.WriteTransport):
+    """Transport for write pipes."""
+
+    _start_tls_compatible = True
+
+    def __init__(self, *args, **kw):
+        super().__init__(*args, **kw)
+        self._empty_waiter = None
+
+    def write(self, data):
+        if not isinstance(data, (bytes, bytearray, memoryview)):
+            raise TypeError(
+                f"data argument must be a bytes-like object, "
+                f"not {type(data).__name__}")
+        if self._eof_written:
+            raise RuntimeError('write_eof() already called')
+        if self._empty_waiter is not None:
+            raise RuntimeError('unable to write; sendfile is in progress')
+
+        if not data:
+            return
+
+        if self._conn_lost:
+            if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES:
+                logger.warning('socket.send() raised exception.')
+            self._conn_lost += 1
+            return
+
+        # Observable states:
+        # 1. IDLE: _write_fut and _buffer both None
+        # 2. WRITING: _write_fut set; _buffer None
+        # 3. BACKED UP: _write_fut set; _buffer a bytearray
+        # We always copy the data, so the caller can't modify it
+        # while we're still waiting for the I/O to happen.
+        if self._write_fut is None:  # IDLE -> WRITING
+            assert self._buffer is None
+            # Pass a copy, except if it's already immutable.
+            self._loop_writing(data=bytes(data))
+        elif not self._buffer:  # WRITING -> BACKED UP
+            # Make a mutable copy which we can extend.
+            self._buffer = bytearray(data)
+            self._maybe_pause_protocol()
+        else:  # BACKED UP
+            # Append to buffer (also copies).
+            self._buffer.extend(data)
+            self._maybe_pause_protocol()
+
+    def _loop_writing(self, f=None, data=None):
+        try:
+            if f is not None and self._write_fut is None and self._closing:
+                # XXX most likely self._force_close() has been called, and
+                # it has set self._write_fut to None.
+                return
+            assert f is self._write_fut
+            self._write_fut = None
+            self._pending_write = 0
+            if f:
+                f.result()
+            if data is None:
+                data = self._buffer
+                self._buffer = None
+            if not data:
+                if self._closing:
+                    self._loop.call_soon(self._call_connection_lost, None)
+                if self._eof_written:
+                    self._sock.shutdown(socket.SHUT_WR)
+                # Now that we've reduced the buffer size, tell the
+                # protocol to resume writing if it was paused.  Note that
+                # we do this last since the callback is called immediately
+                # and it may add more data to the buffer (even causing the
+                # protocol to be paused again).
+                self._maybe_resume_protocol()
+            else:
+                self._write_fut = self._loop._proactor.send(self._sock, data)
+                if not self._write_fut.done():
+                    assert self._pending_write == 0
+                    self._pending_write = len(data)
+                    self._write_fut.add_done_callback(self._loop_writing)
+                    self._maybe_pause_protocol()
+                else:
+                    self._write_fut.add_done_callback(self._loop_writing)
+            if self._empty_waiter is not None and self._write_fut is None:
+                self._empty_waiter.set_result(None)
+        except ConnectionResetError as exc:
+            self._force_close(exc)
+        except OSError as exc:
+            self._fatal_error(exc, 'Fatal write error on pipe transport')
+
+    def can_write_eof(self):
+        return True
+
+    def write_eof(self):
+        self.close()
+
+    def abort(self):
+        self._force_close(None)
+
+    def _make_empty_waiter(self):
+        if self._empty_waiter is not None:
+            raise RuntimeError("Empty waiter is already set")
+        self._empty_waiter = self._loop.create_future()
+        if self._write_fut is None:
+            self._empty_waiter.set_result(None)
+        return self._empty_waiter
+
+    def _reset_empty_waiter(self):
+        self._empty_waiter = None
+
+
+class _ProactorWritePipeTransport(_ProactorBaseWritePipeTransport):
+    def __init__(self, *args, **kw):
+        super().__init__(*args, **kw)
+        self._read_fut = self._loop._proactor.recv(self._sock, 16)
+        self._read_fut.add_done_callback(self._pipe_closed)
+
+    def _pipe_closed(self, fut):
+        if fut.cancelled():
+            # the transport has been closed
+            return
+        assert fut.result() == b''
+        if self._closing:
+            assert self._read_fut is None
+            return
+        assert fut is self._read_fut, (fut, self._read_fut)
+        self._read_fut = None
+        if self._write_fut is not None:
+            self._force_close(BrokenPipeError())
+        else:
+            self.close()
+
+
+class _ProactorDatagramTransport(_ProactorBasePipeTransport,
+                                 transports.DatagramTransport):
+    max_size = 256 * 1024
+    def __init__(self, loop, sock, protocol, address=None,
+                 waiter=None, extra=None):
+        self._address = address
+        self._empty_waiter = None
+        self._buffer_size = 0
+        # We don't need to call _protocol.connection_made() since our base
+        # constructor does it for us.
+        super().__init__(loop, sock, protocol, waiter=waiter, extra=extra)
+
+        # The base constructor sets _buffer = None, so we set it here
+        self._buffer = collections.deque()
+        self._loop.call_soon(self._loop_reading)
+
+    def _set_extra(self, sock):
+        _set_socket_extra(self, sock)
+
+    def get_write_buffer_size(self):
+        return self._buffer_size
+
+    def abort(self):
+        self._force_close(None)
+
+    def sendto(self, data, addr=None):
+        if not isinstance(data, (bytes, bytearray, memoryview)):
+            raise TypeError('data argument must be bytes-like object (%r)',
+                            type(data))
+
+        if self._address is not None and addr not in (None, self._address):
+            raise ValueError(
+                f'Invalid address: must be None or {self._address}')
+
+        if self._conn_lost and self._address:
+            if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES:
+                logger.warning('socket.sendto() raised exception.')
+            self._conn_lost += 1
+            return
+
+        # Ensure that what we buffer is immutable.
+        self._buffer.append((bytes(data), addr))
+        self._buffer_size += len(data) + 8  # include header bytes
+
+        if self._write_fut is None:
+            # No current write operations are active, kick one off
+            self._loop_writing()
+        # else: A write operation is already kicked off
+
+        self._maybe_pause_protocol()
+
+    def _loop_writing(self, fut=None):
+        try:
+            if self._conn_lost:
+                return
+
+            assert fut is self._write_fut
+            self._write_fut = None
+            if fut:
+                # We are in a _loop_writing() done callback, get the result
+                fut.result()
+
+            if not self._buffer or (self._conn_lost and self._address):
+                # The connection has been closed
+                if self._closing:
+                    self._loop.call_soon(self._call_connection_lost, None)
+                return
+
+            data, addr = self._buffer.popleft()
+            self._buffer_size -= len(data)
+            if self._address is not None:
+                self._write_fut = self._loop._proactor.send(self._sock,
+                                                            data)
+            else:
+                self._write_fut = self._loop._proactor.sendto(self._sock,
+                                                              data,
+                                                              addr=addr)
+        except OSError as exc:
+            self._protocol.error_received(exc)
+        except Exception as exc:
+            self._fatal_error(exc, 'Fatal write error on datagram transport')
+        else:
+            self._write_fut.add_done_callback(self._loop_writing)
+            self._maybe_resume_protocol()
+
+    def _loop_reading(self, fut=None):
+        data = None
+        try:
+            if self._conn_lost:
+                return
+
+            assert self._read_fut is fut or (self._read_fut is None and
+                                             self._closing)
+
+            self._read_fut = None
+            if fut is not None:
+                res = fut.result()
+
+                if self._closing:
+                    # since close() has been called we ignore any read data
+                    data = None
+                    return
+
+                if self._address is not None:
+                    data, addr = res, self._address
+                else:
+                    data, addr = res
+
+            if self._conn_lost:
+                return
+            if self._address is not None:
+                self._read_fut = self._loop._proactor.recv(self._sock,
+                                                           self.max_size)
+            else:
+                self._read_fut = self._loop._proactor.recvfrom(self._sock,
+                                                               self.max_size)
+        except OSError as exc:
+            self._protocol.error_received(exc)
+        except exceptions.CancelledError:
+            if not self._closing:
+                raise
+        else:
+            if self._read_fut is not None:
+                self._read_fut.add_done_callback(self._loop_reading)
+        finally:
+            if data:
+                self._protocol.datagram_received(data, addr)
+
+
+class _ProactorDuplexPipeTransport(_ProactorReadPipeTransport,
+                                   _ProactorBaseWritePipeTransport,
+                                   transports.Transport):
+    """Transport for duplex pipes."""
+
+    def can_write_eof(self):
+        return False
+
+    def write_eof(self):
+        raise NotImplementedError
+
+
+class _ProactorSocketTransport(_ProactorReadPipeTransport,
+                               _ProactorBaseWritePipeTransport,
+                               transports.Transport):
+    """Transport for connected sockets."""
+
+    _sendfile_compatible = constants._SendfileMode.TRY_NATIVE
+
+    def __init__(self, loop, sock, protocol, waiter=None,
+                 extra=None, server=None):
+        super().__init__(loop, sock, protocol, waiter, extra, server)
+        base_events._set_nodelay(sock)
+
+    def _set_extra(self, sock):
+        _set_socket_extra(self, sock)
+
+    def can_write_eof(self):
+        return True
+
+    def write_eof(self):
+        if self._closing or self._eof_written:
+            return
+        self._eof_written = True
+        if self._write_fut is None:
+            self._sock.shutdown(socket.SHUT_WR)
+
+
+class BaseProactorEventLoop(base_events.BaseEventLoop):
+
+    def __init__(self, proactor):
+        super().__init__()
+        logger.debug('Using proactor: %s', proactor.__class__.__name__)
+        self._proactor = proactor
+        self._selector = proactor   # convenient alias
+        self._self_reading_future = None
+        self._accept_futures = {}   # socket file descriptor => Future
+        proactor.set_loop(self)
+        self._make_self_pipe()
+        if threading.current_thread() is threading.main_thread():
+            # wakeup fd can only be installed to a file descriptor from the main thread
+            signal.set_wakeup_fd(self._csock.fileno())
+
+    def _make_socket_transport(self, sock, protocol, waiter=None,
+                               extra=None, server=None):
+        return _ProactorSocketTransport(self, sock, protocol, waiter,
+                                        extra, server)
+
+    def _make_ssl_transport(
+            self, rawsock, protocol, sslcontext, waiter=None,
+            *, server_side=False, server_hostname=None,
+            extra=None, server=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
+        ssl_protocol = sslproto.SSLProtocol(
+                self, protocol, sslcontext, waiter,
+                server_side, server_hostname,
+                ssl_handshake_timeout=ssl_handshake_timeout,
+                ssl_shutdown_timeout=ssl_shutdown_timeout)
+        _ProactorSocketTransport(self, rawsock, ssl_protocol,
+                                 extra=extra, server=server)
+        return ssl_protocol._app_transport
+
+    def _make_datagram_transport(self, sock, protocol,
+                                 address=None, waiter=None, extra=None):
+        return _ProactorDatagramTransport(self, sock, protocol, address,
+                                          waiter, extra)
+
+    def _make_duplex_pipe_transport(self, sock, protocol, waiter=None,
+                                    extra=None):
+        return _ProactorDuplexPipeTransport(self,
+                                            sock, protocol, waiter, extra)
+
+    def _make_read_pipe_transport(self, sock, protocol, waiter=None,
+                                  extra=None):
+        return _ProactorReadPipeTransport(self, sock, protocol, waiter, extra)
+
+    def _make_write_pipe_transport(self, sock, protocol, waiter=None,
+                                   extra=None):
+        # We want connection_lost() to be called when other end closes
+        return _ProactorWritePipeTransport(self,
+                                           sock, protocol, waiter, extra)
+
+    def close(self):
+        if self.is_running():
+            raise RuntimeError("Cannot close a running event loop")
+        if self.is_closed():
+            return
+
+        if threading.current_thread() is threading.main_thread():
+            signal.set_wakeup_fd(-1)
+        # Call these methods before closing the event loop (before calling
+        # BaseEventLoop.close), because they can schedule callbacks with
+        # call_soon(), which is forbidden when the event loop is closed.
+        self._stop_accept_futures()
+        self._close_self_pipe()
+        self._proactor.close()
+        self._proactor = None
+        self._selector = None
+
+        # Close the event loop
+        super().close()
+
+    async def sock_recv(self, sock, n):
+        return await self._proactor.recv(sock, n)
+
+    async def sock_recv_into(self, sock, buf):
+        return await self._proactor.recv_into(sock, buf)
+
+    async def sock_recvfrom(self, sock, bufsize):
+        return await self._proactor.recvfrom(sock, bufsize)
+
+    async def sock_recvfrom_into(self, sock, buf, nbytes=0):
+        if not nbytes:
+            nbytes = len(buf)
+
+        return await self._proactor.recvfrom_into(sock, buf, nbytes)
+
+    async def sock_sendall(self, sock, data):
+        return await self._proactor.send(sock, data)
+
+    async def sock_sendto(self, sock, data, address):
+        return await self._proactor.sendto(sock, data, 0, address)
+
+    async def sock_connect(self, sock, address):
+        if self._debug and sock.gettimeout() != 0:
+            raise ValueError("the socket must be non-blocking")
+        return await self._proactor.connect(sock, address)
+
+    async def sock_accept(self, sock):
+        return await self._proactor.accept(sock)
+
+    async def _sock_sendfile_native(self, sock, file, offset, count):
+        try:
+            fileno = file.fileno()
+        except (AttributeError, io.UnsupportedOperation) as err:
+            raise exceptions.SendfileNotAvailableError("not a regular file")
+        try:
+            fsize = os.fstat(fileno).st_size
+        except OSError:
+            raise exceptions.SendfileNotAvailableError("not a regular file")
+        blocksize = count if count else fsize
+        if not blocksize:
+            return 0  # empty file
+
+        blocksize = min(blocksize, 0xffff_ffff)
+        end_pos = min(offset + count, fsize) if count else fsize
+        offset = min(offset, fsize)
+        total_sent = 0
+        try:
+            while True:
+                blocksize = min(end_pos - offset, blocksize)
+                if blocksize <= 0:
+                    return total_sent
+                await self._proactor.sendfile(sock, file, offset, blocksize)
+                offset += blocksize
+                total_sent += blocksize
+        finally:
+            if total_sent > 0:
+                file.seek(offset)
+
+    async def _sendfile_native(self, transp, file, offset, count):
+        resume_reading = transp.is_reading()
+        transp.pause_reading()
+        await transp._make_empty_waiter()
+        try:
+            return await self.sock_sendfile(transp._sock, file, offset, count,
+                                            fallback=False)
+        finally:
+            transp._reset_empty_waiter()
+            if resume_reading:
+                transp.resume_reading()
+
+    def _close_self_pipe(self):
+        if self._self_reading_future is not None:
+            self._self_reading_future.cancel()
+            self._self_reading_future = None
+        self._ssock.close()
+        self._ssock = None
+        self._csock.close()
+        self._csock = None
+        self._internal_fds -= 1
+
+    def _make_self_pipe(self):
+        # A self-socket, really. :-)
+        self._ssock, self._csock = socket.socketpair()
+        self._ssock.setblocking(False)
+        self._csock.setblocking(False)
+        self._internal_fds += 1
+
+    def _loop_self_reading(self, f=None):
+        try:
+            if f is not None:
+                f.result()  # may raise
+            if self._self_reading_future is not f:
+                # When we scheduled this Future, we assigned it to
+                # _self_reading_future. If it's not there now, something has
+                # tried to cancel the loop while this callback was still in the
+                # queue (see windows_events.ProactorEventLoop.run_forever). In
+                # that case stop here instead of continuing to schedule a new
+                # iteration.
+                return
+            f = self._proactor.recv(self._ssock, 4096)
+        except exceptions.CancelledError:
+            # _close_self_pipe() has been called, stop waiting for data
+            return
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as exc:
+            self.call_exception_handler({
+                'message': 'Error on reading from the event loop self pipe',
+                'exception': exc,
+                'loop': self,
+            })
+        else:
+            self._self_reading_future = f
+            f.add_done_callback(self._loop_self_reading)
+
+    def _write_to_self(self):
+        # This may be called from a different thread, possibly after
+        # _close_self_pipe() has been called or even while it is
+        # running.  Guard for self._csock being None or closed.  When
+        # a socket is closed, send() raises OSError (with errno set to
+        # EBADF, but let's not rely on the exact error code).
+        csock = self._csock
+        if csock is None:
+            return
+
+        try:
+            csock.send(b'\0')
+        except OSError:
+            if self._debug:
+                logger.debug("Fail to write a null byte into the "
+                             "self-pipe socket",
+                             exc_info=True)
+
+    def _start_serving(self, protocol_factory, sock,
+                       sslcontext=None, server=None, backlog=100,
+                       ssl_handshake_timeout=None,
+                       ssl_shutdown_timeout=None):
+
+        def loop(f=None):
+            try:
+                if f is not None:
+                    conn, addr = f.result()
+                    if self._debug:
+                        logger.debug("%r got a new connection from %r: %r",
+                                     server, addr, conn)
+                    protocol = protocol_factory()
+                    if sslcontext is not None:
+                        self._make_ssl_transport(
+                            conn, protocol, sslcontext, server_side=True,
+                            extra={'peername': addr}, server=server,
+                            ssl_handshake_timeout=ssl_handshake_timeout,
+                            ssl_shutdown_timeout=ssl_shutdown_timeout)
+                    else:
+                        self._make_socket_transport(
+                            conn, protocol,
+                            extra={'peername': addr}, server=server)
+                if self.is_closed():
+                    return
+                f = self._proactor.accept(sock)
+            except OSError as exc:
+                if sock.fileno() != -1:
+                    self.call_exception_handler({
+                        'message': 'Accept failed on a socket',
+                        'exception': exc,
+                        'socket': trsock.TransportSocket(sock),
+                    })
+                    sock.close()
+                elif self._debug:
+                    logger.debug("Accept failed on socket %r",
+                                 sock, exc_info=True)
+            except exceptions.CancelledError:
+                sock.close()
+            else:
+                self._accept_futures[sock.fileno()] = f
+                f.add_done_callback(loop)
+
+        self.call_soon(loop)
+
+    def _process_events(self, event_list):
+        # Events are processed in the IocpProactor._poll() method
+        pass
+
+    def _stop_accept_futures(self):
+        for future in self._accept_futures.values():
+            future.cancel()
+        self._accept_futures.clear()
+
+    def _stop_serving(self, sock):
+        future = self._accept_futures.pop(sock.fileno(), None)
+        if future:
+            future.cancel()
+        self._proactor._stop_serving(sock)
+        sock.close()

Dependencies/Python/Lib/asyncio/protocols.py

@@ -0,0 +1,216 @@
+"""Abstract Protocol base classes."""
+
+__all__ = (
+    'BaseProtocol', 'Protocol', 'DatagramProtocol',
+    'SubprocessProtocol', 'BufferedProtocol',
+)
+
+
+class BaseProtocol:
+    """Common base class for protocol interfaces.
+
+    Usually user implements protocols that derived from BaseProtocol
+    like Protocol or ProcessProtocol.
+
+    The only case when BaseProtocol should be implemented directly is
+    write-only transport like write pipe
+    """
+
+    __slots__ = ()
+
+    def connection_made(self, transport):
+        """Called when a connection is made.
+
+        The argument is the transport representing the pipe connection.
+        To receive data, wait for data_received() calls.
+        When the connection is closed, connection_lost() is called.
+        """
+
+    def connection_lost(self, exc):
+        """Called when the connection is lost or closed.
+
+        The argument is an exception object or None (the latter
+        meaning a regular EOF is received or the connection was
+        aborted or closed).
+        """
+
+    def pause_writing(self):
+        """Called when the transport's buffer goes over the high-water mark.
+
+        Pause and resume calls are paired -- pause_writing() is called
+        once when the buffer goes strictly over the high-water mark
+        (even if subsequent writes increases the buffer size even
+        more), and eventually resume_writing() is called once when the
+        buffer size reaches the low-water mark.
+
+        Note that if the buffer size equals the high-water mark,
+        pause_writing() is not called -- it must go strictly over.
+        Conversely, resume_writing() is called when the buffer size is
+        equal or lower than the low-water mark.  These end conditions
+        are important to ensure that things go as expected when either
+        mark is zero.
+
+        NOTE: This is the only Protocol callback that is not called
+        through EventLoop.call_soon() -- if it were, it would have no
+        effect when it's most needed (when the app keeps writing
+        without yielding until pause_writing() is called).
+        """
+
+    def resume_writing(self):
+        """Called when the transport's buffer drains below the low-water mark.
+
+        See pause_writing() for details.
+        """
+
+
+class Protocol(BaseProtocol):
+    """Interface for stream protocol.
+
+    The user should implement this interface.  They can inherit from
+    this class but don't need to.  The implementations here do
+    nothing (they don't raise exceptions).
+
+    When the user wants to requests a transport, they pass a protocol
+    factory to a utility function (e.g., EventLoop.create_connection()).
+
+    When the connection is made successfully, connection_made() is
+    called with a suitable transport object.  Then data_received()
+    will be called 0 or more times with data (bytes) received from the
+    transport; finally, connection_lost() will be called exactly once
+    with either an exception object or None as an argument.
+
+    State machine of calls:
+
+      start -> CM [-> DR*] [-> ER?] -> CL -> end
+
+    * CM: connection_made()
+    * DR: data_received()
+    * ER: eof_received()
+    * CL: connection_lost()
+    """
+
+    __slots__ = ()
+
+    def data_received(self, data):
+        """Called when some data is received.
+
+        The argument is a bytes object.
+        """
+
+    def eof_received(self):
+        """Called when the other end calls write_eof() or equivalent.
+
+        If this returns a false value (including None), the transport
+        will close itself.  If it returns a true value, closing the
+        transport is up to the protocol.
+        """
+
+
+class BufferedProtocol(BaseProtocol):
+    """Interface for stream protocol with manual buffer control.
+
+    Event methods, such as `create_server` and `create_connection`,
+    accept factories that return protocols that implement this interface.
+
+    The idea of BufferedProtocol is that it allows to manually allocate
+    and control the receive buffer.  Event loops can then use the buffer
+    provided by the protocol to avoid unnecessary data copies.  This
+    can result in noticeable performance improvement for protocols that
+    receive big amounts of data.  Sophisticated protocols can allocate
+    the buffer only once at creation time.
+
+    State machine of calls:
+
+      start -> CM [-> GB [-> BU?]]* [-> ER?] -> CL -> end
+
+    * CM: connection_made()
+    * GB: get_buffer()
+    * BU: buffer_updated()
+    * ER: eof_received()
+    * CL: connection_lost()
+    """
+
+    __slots__ = ()
+
+    def get_buffer(self, sizehint):
+        """Called to allocate a new receive buffer.
+
+        *sizehint* is a recommended minimal size for the returned
+        buffer.  When set to -1, the buffer size can be arbitrary.
+
+        Must return an object that implements the
+        :ref:`buffer protocol <bufferobjects>`.
+        It is an error to return a zero-sized buffer.
+        """
+
+    def buffer_updated(self, nbytes):
+        """Called when the buffer was updated with the received data.
+
+        *nbytes* is the total number of bytes that were written to
+        the buffer.
+        """
+
+    def eof_received(self):
+        """Called when the other end calls write_eof() or equivalent.
+
+        If this returns a false value (including None), the transport
+        will close itself.  If it returns a true value, closing the
+        transport is up to the protocol.
+        """
+
+
+class DatagramProtocol(BaseProtocol):
+    """Interface for datagram protocol."""
+
+    __slots__ = ()
+
+    def datagram_received(self, data, addr):
+        """Called when some datagram is received."""
+
+    def error_received(self, exc):
+        """Called when a send or receive operation raises an OSError.
+
+        (Other than BlockingIOError or InterruptedError.)
+        """
+
+
+class SubprocessProtocol(BaseProtocol):
+    """Interface for protocol for subprocess calls."""
+
+    __slots__ = ()
+
+    def pipe_data_received(self, fd, data):
+        """Called when the subprocess writes data into stdout/stderr pipe.
+
+        fd is int file descriptor.
+        data is bytes object.
+        """
+
+    def pipe_connection_lost(self, fd, exc):
+        """Called when a file descriptor associated with the child process is
+        closed.
+
+        fd is the int file descriptor that was closed.
+        """
+
+    def process_exited(self):
+        """Called when subprocess has exited."""
+
+
+def _feed_data_to_buffered_proto(proto, data):
+    data_len = len(data)
+    while data_len:
+        buf = proto.get_buffer(data_len)
+        buf_len = len(buf)
+        if not buf_len:
+            raise RuntimeError('get_buffer() returned an empty buffer')
+
+        if buf_len >= data_len:
+            buf[:data_len] = data
+            proto.buffer_updated(data_len)
+            return
+        else:
+            buf[:buf_len] = data[:buf_len]
+            proto.buffer_updated(buf_len)
+            data = data[buf_len:]
+            data_len = len(data)

Dependencies/Python/Lib/asyncio/queues.py

@@ -0,0 +1,308 @@
+__all__ = (
+    'Queue',
+    'PriorityQueue',
+    'LifoQueue',
+    'QueueFull',
+    'QueueEmpty',
+    'QueueShutDown',
+)
+
+import collections
+import heapq
+from types import GenericAlias
+
+from . import locks
+from . import mixins
+
+
+class QueueEmpty(Exception):
+    """Raised when Queue.get_nowait() is called on an empty Queue."""
+    pass
+
+
+class QueueFull(Exception):
+    """Raised when the Queue.put_nowait() method is called on a full Queue."""
+    pass
+
+
+class QueueShutDown(Exception):
+    """Raised when putting on to or getting from a shut-down Queue."""
+    pass
+
+
+class Queue(mixins._LoopBoundMixin):
+    """A queue, useful for coordinating producer and consumer coroutines.
+
+    If maxsize is less than or equal to zero, the queue size is infinite. If it
+    is an integer greater than 0, then "await put()" will block when the
+    queue reaches maxsize, until an item is removed by get().
+
+    Unlike the standard library Queue, you can reliably know this Queue's size
+    with qsize(), since your single-threaded asyncio application won't be
+    interrupted between calling qsize() and doing an operation on the Queue.
+    """
+
+    def __init__(self, maxsize=0):
+        self._maxsize = maxsize
+
+        # Futures.
+        self._getters = collections.deque()
+        # Futures.
+        self._putters = collections.deque()
+        self._unfinished_tasks = 0
+        self._finished = locks.Event()
+        self._finished.set()
+        self._init(maxsize)
+        self._is_shutdown = False
+
+    # These three are overridable in subclasses.
+
+    def _init(self, maxsize):
+        self._queue = collections.deque()
+
+    def _get(self):
+        return self._queue.popleft()
+
+    def _put(self, item):
+        self._queue.append(item)
+
+    # End of the overridable methods.
+
+    def _wakeup_next(self, waiters):
+        # Wake up the next waiter (if any) that isn't cancelled.
+        while waiters:
+            waiter = waiters.popleft()
+            if not waiter.done():
+                waiter.set_result(None)
+                break
+
+    def __repr__(self):
+        return f'<{type(self).__name__} at {id(self):#x} {self._format()}>'
+
+    def __str__(self):
+        return f'<{type(self).__name__} {self._format()}>'
+
+    __class_getitem__ = classmethod(GenericAlias)
+
+    def _format(self):
+        result = f'maxsize={self._maxsize!r}'
+        if getattr(self, '_queue', None):
+            result += f' _queue={list(self._queue)!r}'
+        if self._getters:
+            result += f' _getters[{len(self._getters)}]'
+        if self._putters:
+            result += f' _putters[{len(self._putters)}]'
+        if self._unfinished_tasks:
+            result += f' tasks={self._unfinished_tasks}'
+        if self._is_shutdown:
+            result += ' shutdown'
+        return result
+
+    def qsize(self):
+        """Number of items in the queue."""
+        return len(self._queue)
+
+    @property
+    def maxsize(self):
+        """Number of items allowed in the queue."""
+        return self._maxsize
+
+    def empty(self):
+        """Return True if the queue is empty, False otherwise."""
+        return not self._queue
+
+    def full(self):
+        """Return True if there are maxsize items in the queue.
+
+        Note: if the Queue was initialized with maxsize=0 (the default),
+        then full() is never True.
+        """
+        if self._maxsize <= 0:
+            return False
+        else:
+            return self.qsize() >= self._maxsize
+
+    async def put(self, item):
+        """Put an item into the queue.
+
+        Put an item into the queue. If the queue is full, wait until a free
+        slot is available before adding item.
+
+        Raises QueueShutDown if the queue has been shut down.
+        """
+        while self.full():
+            if self._is_shutdown:
+                raise QueueShutDown
+            putter = self._get_loop().create_future()
+            self._putters.append(putter)
+            try:
+                await putter
+            except:
+                putter.cancel()  # Just in case putter is not done yet.
+                try:
+                    # Clean self._putters from canceled putters.
+                    self._putters.remove(putter)
+                except ValueError:
+                    # The putter could be removed from self._putters by a
+                    # previous get_nowait call or a shutdown call.
+                    pass
+                if not self.full() and not putter.cancelled():
+                    # We were woken up by get_nowait(), but can't take
+                    # the call.  Wake up the next in line.
+                    self._wakeup_next(self._putters)
+                raise
+        return self.put_nowait(item)
+
+    def put_nowait(self, item):
+        """Put an item into the queue without blocking.
+
+        If no free slot is immediately available, raise QueueFull.
+
+        Raises QueueShutDown if the queue has been shut down.
+        """
+        if self._is_shutdown:
+            raise QueueShutDown
+        if self.full():
+            raise QueueFull
+        self._put(item)
+        self._unfinished_tasks += 1
+        self._finished.clear()
+        self._wakeup_next(self._getters)
+
+    async def get(self):
+        """Remove and return an item from the queue.
+
+        If queue is empty, wait until an item is available.
+
+        Raises QueueShutDown if the queue has been shut down and is empty, or
+        if the queue has been shut down immediately.
+        """
+        while self.empty():
+            if self._is_shutdown and self.empty():
+                raise QueueShutDown
+            getter = self._get_loop().create_future()
+            self._getters.append(getter)
+            try:
+                await getter
+            except:
+                getter.cancel()  # Just in case getter is not done yet.
+                try:
+                    # Clean self._getters from canceled getters.
+                    self._getters.remove(getter)
+                except ValueError:
+                    # The getter could be removed from self._getters by a
+                    # previous put_nowait call, or a shutdown call.
+                    pass
+                if not self.empty() and not getter.cancelled():
+                    # We were woken up by put_nowait(), but can't take
+                    # the call.  Wake up the next in line.
+                    self._wakeup_next(self._getters)
+                raise
+        return self.get_nowait()
+
+    def get_nowait(self):
+        """Remove and return an item from the queue.
+
+        Return an item if one is immediately available, else raise QueueEmpty.
+
+        Raises QueueShutDown if the queue has been shut down and is empty, or
+        if the queue has been shut down immediately.
+        """
+        if self.empty():
+            if self._is_shutdown:
+                raise QueueShutDown
+            raise QueueEmpty
+        item = self._get()
+        self._wakeup_next(self._putters)
+        return item
+
+    def task_done(self):
+        """Indicate that a formerly enqueued task is complete.
+
+        Used by queue consumers. For each get() used to fetch a task,
+        a subsequent call to task_done() tells the queue that the processing
+        on the task is complete.
+
+        If a join() is currently blocking, it will resume when all items have
+        been processed (meaning that a task_done() call was received for every
+        item that had been put() into the queue).
+
+        shutdown(immediate=True) calls task_done() for each remaining item in
+        the queue.
+
+        Raises ValueError if called more times than there were items placed in
+        the queue.
+        """
+        if self._unfinished_tasks <= 0:
+            raise ValueError('task_done() called too many times')
+        self._unfinished_tasks -= 1
+        if self._unfinished_tasks == 0:
+            self._finished.set()
+
+    async def join(self):
+        """Block until all items in the queue have been gotten and processed.
+
+        The count of unfinished tasks goes up whenever an item is added to the
+        queue. The count goes down whenever a consumer calls task_done() to
+        indicate that the item was retrieved and all work on it is complete.
+        When the count of unfinished tasks drops to zero, join() unblocks.
+        """
+        if self._unfinished_tasks > 0:
+            await self._finished.wait()
+
+    def shutdown(self, immediate=False):
+        """Shut-down the queue, making queue gets and puts raise QueueShutDown.
+
+        By default, gets will only raise once the queue is empty. Set
+        'immediate' to True to make gets raise immediately instead.
+
+        All blocked callers of put() and get() will be unblocked. If
+        'immediate', a task is marked as done for each item remaining in
+        the queue, which may unblock callers of join().
+        """
+        self._is_shutdown = True
+        if immediate:
+            while not self.empty():
+                self._get()
+                if self._unfinished_tasks > 0:
+                    self._unfinished_tasks -= 1
+            if self._unfinished_tasks == 0:
+                self._finished.set()
+        # All getters need to re-check queue-empty to raise ShutDown
+        while self._getters:
+            getter = self._getters.popleft()
+            if not getter.done():
+                getter.set_result(None)
+        while self._putters:
+            putter = self._putters.popleft()
+            if not putter.done():
+                putter.set_result(None)
+
+
+class PriorityQueue(Queue):
+    """A subclass of Queue; retrieves entries in priority order (lowest first).
+
+    Entries are typically tuples of the form: (priority number, data).
+    """
+
+    def _init(self, maxsize):
+        self._queue = []
+
+    def _put(self, item, heappush=heapq.heappush):
+        heappush(self._queue, item)
+
+    def _get(self, heappop=heapq.heappop):
+        return heappop(self._queue)
+
+
+class LifoQueue(Queue):
+    """A subclass of Queue that retrieves most recently added entries first."""
+
+    def _init(self, maxsize):
+        self._queue = []
+
+    def _put(self, item):
+        self._queue.append(item)
+
+    def _get(self):
+        return self._queue.pop()

Dependencies/Python/Lib/asyncio/runners.py

@@ -0,0 +1,216 @@
+__all__ = ('Runner', 'run')
+
+import contextvars
+import enum
+import functools
+import threading
+import signal
+from . import coroutines
+from . import events
+from . import exceptions
+from . import tasks
+from . import constants
+
+class _State(enum.Enum):
+    CREATED = "created"
+    INITIALIZED = "initialized"
+    CLOSED = "closed"
+
+
+class Runner:
+    """A context manager that controls event loop life cycle.
+
+    The context manager always creates a new event loop,
+    allows to run async functions inside it,
+    and properly finalizes the loop at the context manager exit.
+
+    If debug is True, the event loop will be run in debug mode.
+    If loop_factory is passed, it is used for new event loop creation.
+
+    asyncio.run(main(), debug=True)
+
+    is a shortcut for
+
+    with asyncio.Runner(debug=True) as runner:
+        runner.run(main())
+
+    The run() method can be called multiple times within the runner's context.
+
+    This can be useful for interactive console (e.g. IPython),
+    unittest runners, console tools, -- everywhere when async code
+    is called from existing sync framework and where the preferred single
+    asyncio.run() call doesn't work.
+
+    """
+
+    # Note: the class is final, it is not intended for inheritance.
+
+    def __init__(self, *, debug=None, loop_factory=None):
+        self._state = _State.CREATED
+        self._debug = debug
+        self._loop_factory = loop_factory
+        self._loop = None
+        self._context = None
+        self._interrupt_count = 0
+        self._set_event_loop = False
+
+    def __enter__(self):
+        self._lazy_init()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
+
+    def close(self):
+        """Shutdown and close event loop."""
+        if self._state is not _State.INITIALIZED:
+            return
+        try:
+            loop = self._loop
+            _cancel_all_tasks(loop)
+            loop.run_until_complete(loop.shutdown_asyncgens())
+            loop.run_until_complete(
+                loop.shutdown_default_executor(constants.THREAD_JOIN_TIMEOUT))
+        finally:
+            if self._set_event_loop:
+                events.set_event_loop(None)
+            loop.close()
+            self._loop = None
+            self._state = _State.CLOSED
+
+    def get_loop(self):
+        """Return embedded event loop."""
+        self._lazy_init()
+        return self._loop
+
+    def run(self, coro, *, context=None):
+        """Run a coroutine inside the embedded event loop."""
+        if not coroutines.iscoroutine(coro):
+            raise ValueError("a coroutine was expected, got {!r}".format(coro))
+
+        if events._get_running_loop() is not None:
+            # fail fast with short traceback
+            raise RuntimeError(
+                "Runner.run() cannot be called from a running event loop")
+
+        self._lazy_init()
+
+        if context is None:
+            context = self._context
+        task = self._loop.create_task(coro, context=context)
+
+        if (threading.current_thread() is threading.main_thread()
+            and signal.getsignal(signal.SIGINT) is signal.default_int_handler
+        ):
+            sigint_handler = functools.partial(self._on_sigint, main_task=task)
+            try:
+                signal.signal(signal.SIGINT, sigint_handler)
+            except ValueError:
+                # `signal.signal` may throw if `threading.main_thread` does
+                # not support signals (e.g. embedded interpreter with signals
+                # not registered - see gh-91880)
+                sigint_handler = None
+        else:
+            sigint_handler = None
+
+        self._interrupt_count = 0
+        try:
+            return self._loop.run_until_complete(task)
+        except exceptions.CancelledError:
+            if self._interrupt_count > 0:
+                uncancel = getattr(task, "uncancel", None)
+                if uncancel is not None and uncancel() == 0:
+                    raise KeyboardInterrupt()
+            raise  # CancelledError
+        finally:
+            if (sigint_handler is not None
+                and signal.getsignal(signal.SIGINT) is sigint_handler
+            ):
+                signal.signal(signal.SIGINT, signal.default_int_handler)
+
+    def _lazy_init(self):
+        if self._state is _State.CLOSED:
+            raise RuntimeError("Runner is closed")
+        if self._state is _State.INITIALIZED:
+            return
+        if self._loop_factory is None:
+            self._loop = events.new_event_loop()
+            if not self._set_event_loop:
+                # Call set_event_loop only once to avoid calling
+                # attach_loop multiple times on child watchers
+                events.set_event_loop(self._loop)
+                self._set_event_loop = True
+        else:
+            self._loop = self._loop_factory()
+        if self._debug is not None:
+            self._loop.set_debug(self._debug)
+        self._context = contextvars.copy_context()
+        self._state = _State.INITIALIZED
+
+    def _on_sigint(self, signum, frame, main_task):
+        self._interrupt_count += 1
+        if self._interrupt_count == 1 and not main_task.done():
+            main_task.cancel()
+            # wakeup loop if it is blocked by select() with long timeout
+            self._loop.call_soon_threadsafe(lambda: None)
+            return
+        raise KeyboardInterrupt()
+
+
+def run(main, *, debug=None, loop_factory=None):
+    """Execute the coroutine and return the result.
+
+    This function runs the passed coroutine, taking care of
+    managing the asyncio event loop, finalizing asynchronous
+    generators and closing the default executor.
+
+    This function cannot be called when another asyncio event loop is
+    running in the same thread.
+
+    If debug is True, the event loop will be run in debug mode.
+    If loop_factory is passed, it is used for new event loop creation.
+
+    This function always creates a new event loop and closes it at the end.
+    It should be used as a main entry point for asyncio programs, and should
+    ideally only be called once.
+
+    The executor is given a timeout duration of 5 minutes to shutdown.
+    If the executor hasn't finished within that duration, a warning is
+    emitted and the executor is closed.
+
+    Example:
+
+        async def main():
+            await asyncio.sleep(1)
+            print('hello')
+
+        asyncio.run(main())
+    """
+    if events._get_running_loop() is not None:
+        # fail fast with short traceback
+        raise RuntimeError(
+            "asyncio.run() cannot be called from a running event loop")
+
+    with Runner(debug=debug, loop_factory=loop_factory) as runner:
+        return runner.run(main)
+
+
+def _cancel_all_tasks(loop):
+    to_cancel = tasks.all_tasks(loop)
+    if not to_cancel:
+        return
+
+    for task in to_cancel:
+        task.cancel()
+
+    loop.run_until_complete(tasks.gather(*to_cancel, return_exceptions=True))
+
+    for task in to_cancel:
+        if task.cancelled():
+            continue
+        if task.exception() is not None:
+            loop.call_exception_handler({
+                'message': 'unhandled exception during asyncio.run() shutdown',
+                'exception': task.exception(),
+                'task': task,
+            })

Dependencies/Python/Lib/asyncio/sslproto.py

@@ -0,0 +1,929 @@
+# Contains code from https://github.com/MagicStack/uvloop/tree/v0.16.0
+# SPDX-License-Identifier: PSF-2.0 AND (MIT OR Apache-2.0)
+# SPDX-FileCopyrightText: Copyright (c) 2015-2021 MagicStack Inc.  http://magic.io
+
+import collections
+import enum
+import warnings
+try:
+    import ssl
+except ImportError:  # pragma: no cover
+    ssl = None
+
+from . import constants
+from . import exceptions
+from . import protocols
+from . import transports
+from .log import logger
+
+if ssl is not None:
+    SSLAgainErrors = (ssl.SSLWantReadError, ssl.SSLSyscallError)
+
+
+class SSLProtocolState(enum.Enum):
+    UNWRAPPED = "UNWRAPPED"
+    DO_HANDSHAKE = "DO_HANDSHAKE"
+    WRAPPED = "WRAPPED"
+    FLUSHING = "FLUSHING"
+    SHUTDOWN = "SHUTDOWN"
+
+
+class AppProtocolState(enum.Enum):
+    # This tracks the state of app protocol (https://git.io/fj59P):
+    #
+    #     INIT -cm-> CON_MADE [-dr*->] [-er-> EOF?] -cl-> CON_LOST
+    #
+    # * cm: connection_made()
+    # * dr: data_received()
+    # * er: eof_received()
+    # * cl: connection_lost()
+
+    STATE_INIT = "STATE_INIT"
+    STATE_CON_MADE = "STATE_CON_MADE"
+    STATE_EOF = "STATE_EOF"
+    STATE_CON_LOST = "STATE_CON_LOST"
+
+
+def _create_transport_context(server_side, server_hostname):
+    if server_side:
+        raise ValueError('Server side SSL needs a valid SSLContext')
+
+    # Client side may pass ssl=True to use a default
+    # context; in that case the sslcontext passed is None.
+    # The default is secure for client connections.
+    # Python 3.4+: use up-to-date strong settings.
+    sslcontext = ssl.create_default_context()
+    if not server_hostname:
+        sslcontext.check_hostname = False
+    return sslcontext
+
+
+def add_flowcontrol_defaults(high, low, kb):
+    if high is None:
+        if low is None:
+            hi = kb * 1024
+        else:
+            lo = low
+            hi = 4 * lo
+    else:
+        hi = high
+    if low is None:
+        lo = hi // 4
+    else:
+        lo = low
+
+    if not hi >= lo >= 0:
+        raise ValueError('high (%r) must be >= low (%r) must be >= 0' %
+                         (hi, lo))
+
+    return hi, lo
+
+
+class _SSLProtocolTransport(transports._FlowControlMixin,
+                            transports.Transport):
+
+    _start_tls_compatible = True
+    _sendfile_compatible = constants._SendfileMode.FALLBACK
+
+    def __init__(self, loop, ssl_protocol):
+        self._loop = loop
+        self._ssl_protocol = ssl_protocol
+        self._closed = False
+
+    def get_extra_info(self, name, default=None):
+        """Get optional transport information."""
+        return self._ssl_protocol._get_extra_info(name, default)
+
+    def set_protocol(self, protocol):
+        self._ssl_protocol._set_app_protocol(protocol)
+
+    def get_protocol(self):
+        return self._ssl_protocol._app_protocol
+
+    def is_closing(self):
+        return self._closed or self._ssl_protocol._is_transport_closing()
+
+    def close(self):
+        """Close the transport.
+
+        Buffered data will be flushed asynchronously.  No more data
+        will be received.  After all buffered data is flushed, the
+        protocol's connection_lost() method will (eventually) called
+        with None as its argument.
+        """
+        if not self._closed:
+            self._closed = True
+            self._ssl_protocol._start_shutdown()
+        else:
+            self._ssl_protocol = None
+
+    def __del__(self, _warnings=warnings):
+        if not self._closed:
+            self._closed = True
+            _warnings.warn(
+                "unclosed transport <asyncio._SSLProtocolTransport "
+                "object>", ResourceWarning)
+
+    def is_reading(self):
+        return not self._ssl_protocol._app_reading_paused
+
+    def pause_reading(self):
+        """Pause the receiving end.
+
+        No data will be passed to the protocol's data_received()
+        method until resume_reading() is called.
+        """
+        self._ssl_protocol._pause_reading()
+
+    def resume_reading(self):
+        """Resume the receiving end.
+
+        Data received will once again be passed to the protocol's
+        data_received() method.
+        """
+        self._ssl_protocol._resume_reading()
+
+    def set_write_buffer_limits(self, high=None, low=None):
+        """Set the high- and low-water limits for write flow control.
+
+        These two values control when to call the protocol's
+        pause_writing() and resume_writing() methods.  If specified,
+        the low-water limit must be less than or equal to the
+        high-water limit.  Neither value can be negative.
+
+        The defaults are implementation-specific.  If only the
+        high-water limit is given, the low-water limit defaults to an
+        implementation-specific value less than or equal to the
+        high-water limit.  Setting high to zero forces low to zero as
+        well, and causes pause_writing() to be called whenever the
+        buffer becomes non-empty.  Setting low to zero causes
+        resume_writing() to be called only once the buffer is empty.
+        Use of zero for either limit is generally sub-optimal as it
+        reduces opportunities for doing I/O and computation
+        concurrently.
+        """
+        self._ssl_protocol._set_write_buffer_limits(high, low)
+        self._ssl_protocol._control_app_writing()
+
+    def get_write_buffer_limits(self):
+        return (self._ssl_protocol._outgoing_low_water,
+                self._ssl_protocol._outgoing_high_water)
+
+    def get_write_buffer_size(self):
+        """Return the current size of the write buffers."""
+        return self._ssl_protocol._get_write_buffer_size()
+
+    def set_read_buffer_limits(self, high=None, low=None):
+        """Set the high- and low-water limits for read flow control.
+
+        These two values control when to call the upstream transport's
+        pause_reading() and resume_reading() methods.  If specified,
+        the low-water limit must be less than or equal to the
+        high-water limit.  Neither value can be negative.
+
+        The defaults are implementation-specific.  If only the
+        high-water limit is given, the low-water limit defaults to an
+        implementation-specific value less than or equal to the
+        high-water limit.  Setting high to zero forces low to zero as
+        well, and causes pause_reading() to be called whenever the
+        buffer becomes non-empty.  Setting low to zero causes
+        resume_reading() to be called only once the buffer is empty.
+        Use of zero for either limit is generally sub-optimal as it
+        reduces opportunities for doing I/O and computation
+        concurrently.
+        """
+        self._ssl_protocol._set_read_buffer_limits(high, low)
+        self._ssl_protocol._control_ssl_reading()
+
+    def get_read_buffer_limits(self):
+        return (self._ssl_protocol._incoming_low_water,
+                self._ssl_protocol._incoming_high_water)
+
+    def get_read_buffer_size(self):
+        """Return the current size of the read buffer."""
+        return self._ssl_protocol._get_read_buffer_size()
+
+    @property
+    def _protocol_paused(self):
+        # Required for sendfile fallback pause_writing/resume_writing logic
+        return self._ssl_protocol._app_writing_paused
+
+    def write(self, data):
+        """Write some data bytes to the transport.
+
+        This does not block; it buffers the data and arranges for it
+        to be sent out asynchronously.
+        """
+        if not isinstance(data, (bytes, bytearray, memoryview)):
+            raise TypeError(f"data: expecting a bytes-like instance, "
+                            f"got {type(data).__name__}")
+        if not data:
+            return
+        self._ssl_protocol._write_appdata((data,))
+
+    def writelines(self, list_of_data):
+        """Write a list (or any iterable) of data bytes to the transport.
+
+        The default implementation concatenates the arguments and
+        calls write() on the result.
+        """
+        self._ssl_protocol._write_appdata(list_of_data)
+
+    def write_eof(self):
+        """Close the write end after flushing buffered data.
+
+        This raises :exc:`NotImplementedError` right now.
+        """
+        raise NotImplementedError
+
+    def can_write_eof(self):
+        """Return True if this transport supports write_eof(), False if not."""
+        return False
+
+    def abort(self):
+        """Close the transport immediately.
+
+        Buffered data will be lost.  No more data will be received.
+        The protocol's connection_lost() method will (eventually) be
+        called with None as its argument.
+        """
+        self._force_close(None)
+
+    def _force_close(self, exc):
+        self._closed = True
+        if self._ssl_protocol is not None:
+            self._ssl_protocol._abort(exc)
+
+    def _test__append_write_backlog(self, data):
+        # for test only
+        self._ssl_protocol._write_backlog.append(data)
+        self._ssl_protocol._write_buffer_size += len(data)
+
+
+class SSLProtocol(protocols.BufferedProtocol):
+    max_size = 256 * 1024   # Buffer size passed to read()
+
+    _handshake_start_time = None
+    _handshake_timeout_handle = None
+    _shutdown_timeout_handle = None
+
+    def __init__(self, loop, app_protocol, sslcontext, waiter,
+                 server_side=False, server_hostname=None,
+                 call_connection_made=True,
+                 ssl_handshake_timeout=None,
+                 ssl_shutdown_timeout=None):
+        if ssl is None:
+            raise RuntimeError("stdlib ssl module not available")
+
+        self._ssl_buffer = bytearray(self.max_size)
+        self._ssl_buffer_view = memoryview(self._ssl_buffer)
+
+        if ssl_handshake_timeout is None:
+            ssl_handshake_timeout = constants.SSL_HANDSHAKE_TIMEOUT
+        elif ssl_handshake_timeout <= 0:
+            raise ValueError(
+                f"ssl_handshake_timeout should be a positive number, "
+                f"got {ssl_handshake_timeout}")
+        if ssl_shutdown_timeout is None:
+            ssl_shutdown_timeout = constants.SSL_SHUTDOWN_TIMEOUT
+        elif ssl_shutdown_timeout <= 0:
+            raise ValueError(
+                f"ssl_shutdown_timeout should be a positive number, "
+                f"got {ssl_shutdown_timeout}")
+
+        if not sslcontext:
+            sslcontext = _create_transport_context(
+                server_side, server_hostname)
+
+        self._server_side = server_side
+        if server_hostname and not server_side:
+            self._server_hostname = server_hostname
+        else:
+            self._server_hostname = None
+        self._sslcontext = sslcontext
+        # SSL-specific extra info. More info are set when the handshake
+        # completes.
+        self._extra = dict(sslcontext=sslcontext)
+
+        # App data write buffering
+        self._write_backlog = collections.deque()
+        self._write_buffer_size = 0
+
+        self._waiter = waiter
+        self._loop = loop
+        self._set_app_protocol(app_protocol)
+        self._app_transport = None
+        self._app_transport_created = False
+        # transport, ex: SelectorSocketTransport
+        self._transport = None
+        self._ssl_handshake_timeout = ssl_handshake_timeout
+        self._ssl_shutdown_timeout = ssl_shutdown_timeout
+        # SSL and state machine
+        self._incoming = ssl.MemoryBIO()
+        self._outgoing = ssl.MemoryBIO()
+        self._state = SSLProtocolState.UNWRAPPED
+        self._conn_lost = 0  # Set when connection_lost called
+        if call_connection_made:
+            self._app_state = AppProtocolState.STATE_INIT
+        else:
+            self._app_state = AppProtocolState.STATE_CON_MADE
+        self._sslobj = self._sslcontext.wrap_bio(
+            self._incoming, self._outgoing,
+            server_side=self._server_side,
+            server_hostname=self._server_hostname)
+
+        # Flow Control
+
+        self._ssl_writing_paused = False
+
+        self._app_reading_paused = False
+
+        self._ssl_reading_paused = False
+        self._incoming_high_water = 0
+        self._incoming_low_water = 0
+        self._set_read_buffer_limits()
+        self._eof_received = False
+
+        self._app_writing_paused = False
+        self._outgoing_high_water = 0
+        self._outgoing_low_water = 0
+        self._set_write_buffer_limits()
+        self._get_app_transport()
+
+    def _set_app_protocol(self, app_protocol):
+        self._app_protocol = app_protocol
+        # Make fast hasattr check first
+        if (hasattr(app_protocol, 'get_buffer') and
+                isinstance(app_protocol, protocols.BufferedProtocol)):
+            self._app_protocol_get_buffer = app_protocol.get_buffer
+            self._app_protocol_buffer_updated = app_protocol.buffer_updated
+            self._app_protocol_is_buffer = True
+        else:
+            self._app_protocol_is_buffer = False
+
+    def _wakeup_waiter(self, exc=None):
+        if self._waiter is None:
+            return
+        if not self._waiter.cancelled():
+            if exc is not None:
+                self._waiter.set_exception(exc)
+            else:
+                self._waiter.set_result(None)
+        self._waiter = None
+
+    def _get_app_transport(self):
+        if self._app_transport is None:
+            if self._app_transport_created:
+                raise RuntimeError('Creating _SSLProtocolTransport twice')
+            self._app_transport = _SSLProtocolTransport(self._loop, self)
+            self._app_transport_created = True
+        return self._app_transport
+
+    def _is_transport_closing(self):
+        return self._transport is not None and self._transport.is_closing()
+
+    def connection_made(self, transport):
+        """Called when the low-level connection is made.
+
+        Start the SSL handshake.
+        """
+        self._transport = transport
+        self._start_handshake()
+
+    def connection_lost(self, exc):
+        """Called when the low-level connection is lost or closed.
+
+        The argument is an exception object or None (the latter
+        meaning a regular EOF is received or the connection was
+        aborted or closed).
+        """
+        self._write_backlog.clear()
+        self._outgoing.read()
+        self._conn_lost += 1
+
+        # Just mark the app transport as closed so that its __dealloc__
+        # doesn't complain.
+        if self._app_transport is not None:
+            self._app_transport._closed = True
+
+        if self._state != SSLProtocolState.DO_HANDSHAKE:
+            if (
+                self._app_state == AppProtocolState.STATE_CON_MADE or
+                self._app_state == AppProtocolState.STATE_EOF
+            ):
+                self._app_state = AppProtocolState.STATE_CON_LOST
+                self._loop.call_soon(self._app_protocol.connection_lost, exc)
+        self._set_state(SSLProtocolState.UNWRAPPED)
+        self._transport = None
+        self._app_transport = None
+        self._app_protocol = None
+        self._wakeup_waiter(exc)
+
+        if self._shutdown_timeout_handle:
+            self._shutdown_timeout_handle.cancel()
+            self._shutdown_timeout_handle = None
+        if self._handshake_timeout_handle:
+            self._handshake_timeout_handle.cancel()
+            self._handshake_timeout_handle = None
+
+    def get_buffer(self, n):
+        want = n
+        if want <= 0 or want > self.max_size:
+            want = self.max_size
+        if len(self._ssl_buffer) < want:
+            self._ssl_buffer = bytearray(want)
+            self._ssl_buffer_view = memoryview(self._ssl_buffer)
+        return self._ssl_buffer_view
+
+    def buffer_updated(self, nbytes):
+        self._incoming.write(self._ssl_buffer_view[:nbytes])
+
+        if self._state == SSLProtocolState.DO_HANDSHAKE:
+            self._do_handshake()
+
+        elif self._state == SSLProtocolState.WRAPPED:
+            self._do_read()
+
+        elif self._state == SSLProtocolState.FLUSHING:
+            self._do_flush()
+
+        elif self._state == SSLProtocolState.SHUTDOWN:
+            self._do_shutdown()
+
+    def eof_received(self):
+        """Called when the other end of the low-level stream
+        is half-closed.
+
+        If this returns a false value (including None), the transport
+        will close itself.  If it returns a true value, closing the
+        transport is up to the protocol.
+        """
+        self._eof_received = True
+        try:
+            if self._loop.get_debug():
+                logger.debug("%r received EOF", self)
+
+            if self._state == SSLProtocolState.DO_HANDSHAKE:
+                self._on_handshake_complete(ConnectionResetError)
+
+            elif self._state == SSLProtocolState.WRAPPED:
+                self._set_state(SSLProtocolState.FLUSHING)
+                if self._app_reading_paused:
+                    return True
+                else:
+                    self._do_flush()
+
+            elif self._state == SSLProtocolState.FLUSHING:
+                self._do_write()
+                self._set_state(SSLProtocolState.SHUTDOWN)
+                self._do_shutdown()
+
+            elif self._state == SSLProtocolState.SHUTDOWN:
+                self._do_shutdown()
+
+        except Exception:
+            self._transport.close()
+            raise
+
+    def _get_extra_info(self, name, default=None):
+        if name in self._extra:
+            return self._extra[name]
+        elif self._transport is not None:
+            return self._transport.get_extra_info(name, default)
+        else:
+            return default
+
+    def _set_state(self, new_state):
+        allowed = False
+
+        if new_state == SSLProtocolState.UNWRAPPED:
+            allowed = True
+
+        elif (
+            self._state == SSLProtocolState.UNWRAPPED and
+            new_state == SSLProtocolState.DO_HANDSHAKE
+        ):
+            allowed = True
+
+        elif (
+            self._state == SSLProtocolState.DO_HANDSHAKE and
+            new_state == SSLProtocolState.WRAPPED
+        ):
+            allowed = True
+
+        elif (
+            self._state == SSLProtocolState.WRAPPED and
+            new_state == SSLProtocolState.FLUSHING
+        ):
+            allowed = True
+
+        elif (
+            self._state == SSLProtocolState.FLUSHING and
+            new_state == SSLProtocolState.SHUTDOWN
+        ):
+            allowed = True
+
+        if allowed:
+            self._state = new_state
+
+        else:
+            raise RuntimeError(
+                'cannot switch state from {} to {}'.format(
+                    self._state, new_state))
+
+    # Handshake flow
+
+    def _start_handshake(self):
+        if self._loop.get_debug():
+            logger.debug("%r starts SSL handshake", self)
+            self._handshake_start_time = self._loop.time()
+        else:
+            self._handshake_start_time = None
+
+        self._set_state(SSLProtocolState.DO_HANDSHAKE)
+
+        # start handshake timeout count down
+        self._handshake_timeout_handle = \
+            self._loop.call_later(self._ssl_handshake_timeout,
+                                  self._check_handshake_timeout)
+
+        self._do_handshake()
+
+    def _check_handshake_timeout(self):
+        if self._state == SSLProtocolState.DO_HANDSHAKE:
+            msg = (
+                f"SSL handshake is taking longer than "
+                f"{self._ssl_handshake_timeout} seconds: "
+                f"aborting the connection"
+            )
+            self._fatal_error(ConnectionAbortedError(msg))
+
+    def _do_handshake(self):
+        try:
+            self._sslobj.do_handshake()
+        except SSLAgainErrors:
+            self._process_outgoing()
+        except ssl.SSLError as exc:
+            self._on_handshake_complete(exc)
+        else:
+            self._on_handshake_complete(None)
+
+    def _on_handshake_complete(self, handshake_exc):
+        if self._handshake_timeout_handle is not None:
+            self._handshake_timeout_handle.cancel()
+            self._handshake_timeout_handle = None
+
+        sslobj = self._sslobj
+        try:
+            if handshake_exc is None:
+                self._set_state(SSLProtocolState.WRAPPED)
+            else:
+                raise handshake_exc
+
+            peercert = sslobj.getpeercert()
+        except Exception as exc:
+            handshake_exc = None
+            self._set_state(SSLProtocolState.UNWRAPPED)
+            if isinstance(exc, ssl.CertificateError):
+                msg = 'SSL handshake failed on verifying the certificate'
+            else:
+                msg = 'SSL handshake failed'
+            self._fatal_error(exc, msg)
+            self._wakeup_waiter(exc)
+            return
+
+        if self._loop.get_debug():
+            dt = self._loop.time() - self._handshake_start_time
+            logger.debug("%r: SSL handshake took %.1f ms", self, dt * 1e3)
+
+        # Add extra info that becomes available after handshake.
+        self._extra.update(peercert=peercert,
+                           cipher=sslobj.cipher(),
+                           compression=sslobj.compression(),
+                           ssl_object=sslobj)
+        if self._app_state == AppProtocolState.STATE_INIT:
+            self._app_state = AppProtocolState.STATE_CON_MADE
+            self._app_protocol.connection_made(self._get_app_transport())
+        self._wakeup_waiter()
+        self._do_read()
+
+    # Shutdown flow
+
+    def _start_shutdown(self):
+        if (
+            self._state in (
+                SSLProtocolState.FLUSHING,
+                SSLProtocolState.SHUTDOWN,
+                SSLProtocolState.UNWRAPPED
+            )
+        ):
+            return
+        if self._app_transport is not None:
+            self._app_transport._closed = True
+        if self._state == SSLProtocolState.DO_HANDSHAKE:
+            self._abort(None)
+        else:
+            self._set_state(SSLProtocolState.FLUSHING)
+            self._shutdown_timeout_handle = self._loop.call_later(
+                self._ssl_shutdown_timeout,
+                self._check_shutdown_timeout
+            )
+            self._do_flush()
+
+    def _check_shutdown_timeout(self):
+        if (
+            self._state in (
+                SSLProtocolState.FLUSHING,
+                SSLProtocolState.SHUTDOWN
+            )
+        ):
+            self._transport._force_close(
+                exceptions.TimeoutError('SSL shutdown timed out'))
+
+    def _do_flush(self):
+        self._do_read()
+        self._set_state(SSLProtocolState.SHUTDOWN)
+        self._do_shutdown()
+
+    def _do_shutdown(self):
+        try:
+            if not self._eof_received:
+                self._sslobj.unwrap()
+        except SSLAgainErrors:
+            self._process_outgoing()
+        except ssl.SSLError as exc:
+            self._on_shutdown_complete(exc)
+        else:
+            self._process_outgoing()
+            self._call_eof_received()
+            self._on_shutdown_complete(None)
+
+    def _on_shutdown_complete(self, shutdown_exc):
+        if self._shutdown_timeout_handle is not None:
+            self._shutdown_timeout_handle.cancel()
+            self._shutdown_timeout_handle = None
+
+        if shutdown_exc:
+            self._fatal_error(shutdown_exc)
+        else:
+            self._loop.call_soon(self._transport.close)
+
+    def _abort(self, exc):
+        self._set_state(SSLProtocolState.UNWRAPPED)
+        if self._transport is not None:
+            self._transport._force_close(exc)
+
+    # Outgoing flow
+
+    def _write_appdata(self, list_of_data):
+        if (
+            self._state in (
+                SSLProtocolState.FLUSHING,
+                SSLProtocolState.SHUTDOWN,
+                SSLProtocolState.UNWRAPPED
+            )
+        ):
+            if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES:
+                logger.warning('SSL connection is closed')
+            self._conn_lost += 1
+            return
+
+        for data in list_of_data:
+            self._write_backlog.append(data)
+            self._write_buffer_size += len(data)
+
+        try:
+            if self._state == SSLProtocolState.WRAPPED:
+                self._do_write()
+
+        except Exception as ex:
+            self._fatal_error(ex, 'Fatal error on SSL protocol')
+
+    def _do_write(self):
+        try:
+            while self._write_backlog:
+                data = self._write_backlog[0]
+                count = self._sslobj.write(data)
+                data_len = len(data)
+                if count < data_len:
+                    self._write_backlog[0] = data[count:]
+                    self._write_buffer_size -= count
+                else:
+                    del self._write_backlog[0]
+                    self._write_buffer_size -= data_len
+        except SSLAgainErrors:
+            pass
+        self._process_outgoing()
+
+    def _process_outgoing(self):
+        if not self._ssl_writing_paused:
+            data = self._outgoing.read()
+            if len(data):
+                self._transport.write(data)
+        self._control_app_writing()
+
+    # Incoming flow
+
+    def _do_read(self):
+        if (
+            self._state not in (
+                SSLProtocolState.WRAPPED,
+                SSLProtocolState.FLUSHING,
+            )
+        ):
+            return
+        try:
+            if not self._app_reading_paused:
+                if self._app_protocol_is_buffer:
+                    self._do_read__buffered()
+                else:
+                    self._do_read__copied()
+                if self._write_backlog:
+                    self._do_write()
+                else:
+                    self._process_outgoing()
+            self._control_ssl_reading()
+        except Exception as ex:
+            self._fatal_error(ex, 'Fatal error on SSL protocol')
+
+    def _do_read__buffered(self):
+        offset = 0
+        count = 1
+
+        buf = self._app_protocol_get_buffer(self._get_read_buffer_size())
+        wants = len(buf)
+
+        try:
+            count = self._sslobj.read(wants, buf)
+
+            if count > 0:
+                offset = count
+                while offset < wants:
+                    count = self._sslobj.read(wants - offset, buf[offset:])
+                    if count > 0:
+                        offset += count
+                    else:
+                        break
+                else:
+                    self._loop.call_soon(self._do_read)
+        except SSLAgainErrors:
+            pass
+        if offset > 0:
+            self._app_protocol_buffer_updated(offset)
+        if not count:
+            # close_notify
+            self._call_eof_received()
+            self._start_shutdown()
+
+    def _do_read__copied(self):
+        chunk = b'1'
+        zero = True
+        one = False
+
+        try:
+            while True:
+                chunk = self._sslobj.read(self.max_size)
+                if not chunk:
+                    break
+                if zero:
+                    zero = False
+                    one = True
+                    first = chunk
+                elif one:
+                    one = False
+                    data = [first, chunk]
+                else:
+                    data.append(chunk)
+        except SSLAgainErrors:
+            pass
+        if one:
+            self._app_protocol.data_received(first)
+        elif not zero:
+            self._app_protocol.data_received(b''.join(data))
+        if not chunk:
+            # close_notify
+            self._call_eof_received()
+            self._start_shutdown()
+
+    def _call_eof_received(self):
+        try:
+            if self._app_state == AppProtocolState.STATE_CON_MADE:
+                self._app_state = AppProtocolState.STATE_EOF
+                keep_open = self._app_protocol.eof_received()
+                if keep_open:
+                    logger.warning('returning true from eof_received() '
+                                   'has no effect when using ssl')
+        except (KeyboardInterrupt, SystemExit):
+            raise
+        except BaseException as ex:
+            self._fatal_error(ex, 'Error calling eof_received()')
+
+    # Flow control for writes from APP socket
+
+    def _control_app_writing(self):
+        size = self._get_write_buffer_size()
+        if size >= self._outgoing_high_water and not self._app_writing_paused:
+            self._app_writing_paused = True
+            try:
+                self._app_protocol.pause_writing()
+            except (KeyboardInterrupt, SystemExit):
+                raise
+            except BaseException as exc:
+                self._loop.call_exception_handler({
+                    'message': 'protocol.pause_writing() failed',
+                    'exception': exc,
+                    'transport': self._app_transport,
+                    'protocol': self,
+                })
+        elif size <= self._outgoing_low_water and self._app_writing_paused:
+            self._app_writing_paused = False
+            try:
+                self._app_protocol.resume_writing()
+            except (KeyboardInterrupt, SystemExit):
+                raise
+            except BaseException as exc:
+                self._loop.call_exception_handler({
+                    'message': 'protocol.resume_writing() failed',
+                    'exception': exc,
+                    'transport': self._app_transport,
+                    'protocol': self,
+                })
+
+    def _get_write_buffer_size(self):
+        return self._outgoing.pending + self._write_buffer_size
+
+    def _set_write_buffer_limits(self, high=None, low=None):
+        high, low = add_flowcontrol_defaults(
+            high, low, constants.FLOW_CONTROL_HIGH_WATER_SSL_WRITE)
+        self._outgoing_high_water = high
+        self._outgoing_low_water = low
+
+    # Flow control for reads to APP socket
+
+    def _pause_reading(self):
+        self._app_reading_paused = True
+
+    def _resume_reading(self):
+        if self._app_reading_paused:
+            self._app_reading_paused = False
+
+            def resume():
+                if self._state == SSLProtocolState.WRAPPED:
+                    self._do_read()
+                elif self._state == SSLProtocolState.FLUSHING:
+                    self._do_flush()
+                elif self._state == SSLProtocolState.SHUTDOWN:
+                    self._do_shutdown()
+            self._loop.call_soon(resume)
+
+    # Flow control for reads from SSL socket
+
+    def _control_ssl_reading(self):
+        size = self._get_read_buffer_size()
+        if size >= self._incoming_high_water and not self._ssl_reading_paused:
+            self._ssl_reading_paused = True
+            self._transport.pause_reading()
+        elif size <= self._incoming_low_water and self._ssl_reading_paused:
+            self._ssl_reading_paused = False
+            self._transport.resume_reading()
+
+    def _set_read_buffer_limits(self, high=None, low=None):
+        high, low = add_flowcontrol_defaults(
+            high, low, constants.FLOW_CONTROL_HIGH_WATER_SSL_READ)
+        self._incoming_high_water = high
+        self._incoming_low_water = low
+
+    def _get_read_buffer_size(self):
+        return self._incoming.pending
+
+    # Flow control for writes to SSL socket
+
+    def pause_writing(self):
+        """Called when the low-level transport's buffer goes over
+        the high-water mark.
+        """
+        assert not self._ssl_writing_paused
+        self._ssl_writing_paused = True
+
+    def resume_writing(self):
+        """Called when the low-level transport's buffer drains below
+        the low-water mark.
+        """
+        assert self._ssl_writing_paused
+        self._ssl_writing_paused = False
+        self._process_outgoing()
+
+    def _fatal_error(self, exc, message='Fatal error on transport'):
+        if self._transport:
+            self._transport._force_close(exc)
+
+        if isinstance(exc, OSError):
+            if self._loop.get_debug():
+                logger.debug("%r: %s", self, message, exc_info=True)
+        elif not isinstance(exc, exceptions.CancelledError):
+            self._loop.call_exception_handler({
+                'message': message,
+                'exception': exc,
+                'transport': self._transport,
+                'protocol': self,
+            })

Dependencies/Python/Lib/asyncio/staggered.py

@@ -0,0 +1,174 @@
+"""Support for running coroutines in parallel with staggered start times."""
+
+__all__ = 'staggered_race',
+
+import contextlib
+
+from . import events
+from . import exceptions as exceptions_mod
+from . import locks
+from . import tasks
+
+
+async def staggered_race(coro_fns, delay, *, loop=None):
+    """Run coroutines with staggered start times and take the first to finish.
+
+    This method takes an iterable of coroutine functions. The first one is
+    started immediately. From then on, whenever the immediately preceding one
+    fails (raises an exception), or when *delay* seconds has passed, the next
+    coroutine is started. This continues until one of the coroutines complete
+    successfully, in which case all others are cancelled, or until all
+    coroutines fail.
+
+    The coroutines provided should be well-behaved in the following way:
+
+    * They should only ``return`` if completed successfully.
+
+    * They should always raise an exception if they did not complete
+      successfully. In particular, if they handle cancellation, they should
+      probably reraise, like this::
+
+        try:
+            # do work
+        except asyncio.CancelledError:
+            # undo partially completed work
+            raise
+
+    Args:
+        coro_fns: an iterable of coroutine functions, i.e. callables that
+            return a coroutine object when called. Use ``functools.partial`` or
+            lambdas to pass arguments.
+
+        delay: amount of time, in seconds, between starting coroutines. If
+            ``None``, the coroutines will run sequentially.
+
+        loop: the event loop to use.
+
+    Returns:
+        tuple *(winner_result, winner_index, exceptions)* where
+
+        - *winner_result*: the result of the winning coroutine, or ``None``
+          if no coroutines won.
+
+        - *winner_index*: the index of the winning coroutine in
+          ``coro_fns``, or ``None`` if no coroutines won. If the winning
+          coroutine may return None on success, *winner_index* can be used
+          to definitively determine whether any coroutine won.
+
+        - *exceptions*: list of exceptions returned by the coroutines.
+          ``len(exceptions)`` is equal to the number of coroutines actually
+          started, and the order is the same as in ``coro_fns``. The winning
+          coroutine's entry is ``None``.
+
+    """
+    # TODO: when we have aiter() and anext(), allow async iterables in coro_fns.
+    loop = loop or events.get_running_loop()
+    enum_coro_fns = enumerate(coro_fns)
+    winner_result = None
+    winner_index = None
+    unhandled_exceptions = []
+    exceptions = []
+    running_tasks = set()
+    on_completed_fut = None
+
+    def task_done(task):
+        running_tasks.discard(task)
+        if (
+            on_completed_fut is not None
+            and not on_completed_fut.done()
+            and not running_tasks
+        ):
+            on_completed_fut.set_result(None)
+
+        if task.cancelled():
+            return
+
+        exc = task.exception()
+        if exc is None:
+            return
+        unhandled_exceptions.append(exc)
+
+    async def run_one_coro(ok_to_start, previous_failed) -> None:
+        # in eager tasks this waits for the calling task to append this task
+        # to running_tasks, in regular tasks this wait is a no-op that does
+        # not yield a future. See gh-124309.
+        await ok_to_start.wait()
+        # Wait for the previous task to finish, or for delay seconds
+        if previous_failed is not None:
+            with contextlib.suppress(exceptions_mod.TimeoutError):
+                # Use asyncio.wait_for() instead of asyncio.wait() here, so
+                # that if we get cancelled at this point, Event.wait() is also
+                # cancelled, otherwise there will be a "Task destroyed but it is
+                # pending" later.
+                await tasks.wait_for(previous_failed.wait(), delay)
+        # Get the next coroutine to run
+        try:
+            this_index, coro_fn = next(enum_coro_fns)
+        except StopIteration:
+            return
+        # Start task that will run the next coroutine
+        this_failed = locks.Event()
+        next_ok_to_start = locks.Event()
+        next_task = loop.create_task(run_one_coro(next_ok_to_start, this_failed))
+        running_tasks.add(next_task)
+        next_task.add_done_callback(task_done)
+        # next_task has been appended to running_tasks so next_task is ok to
+        # start.
+        next_ok_to_start.set()
+        # Prepare place to put this coroutine's exceptions if not won
+        exceptions.append(None)
+        assert len(exceptions) == this_index + 1
+
+        try:
+            result = await coro_fn()
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as e:
+            exceptions[this_index] = e
+            this_failed.set()  # Kickstart the next coroutine
+        else:
+            # Store winner's results
+            nonlocal winner_index, winner_result
+            assert winner_index is None
+            winner_index = this_index
+            winner_result = result
+            # Cancel all other tasks. We take care to not cancel the current
+            # task as well. If we do so, then since there is no `await` after
+            # here and CancelledError are usually thrown at one, we will
+            # encounter a curious corner case where the current task will end
+            # up as done() == True, cancelled() == False, exception() ==
+            # asyncio.CancelledError. This behavior is specified in
+            # https://bugs.python.org/issue30048
+            current_task = tasks.current_task(loop)
+            for t in running_tasks:
+                if t is not current_task:
+                    t.cancel()
+
+    propagate_cancellation_error = None
+    try:
+        ok_to_start = locks.Event()
+        first_task = loop.create_task(run_one_coro(ok_to_start, None))
+        running_tasks.add(first_task)
+        first_task.add_done_callback(task_done)
+        # first_task has been appended to running_tasks so first_task is ok to start.
+        ok_to_start.set()
+        propagate_cancellation_error = None
+        # Make sure no tasks are left running if we leave this function
+        while running_tasks:
+            on_completed_fut = loop.create_future()
+            try:
+                await on_completed_fut
+            except exceptions_mod.CancelledError as ex:
+                propagate_cancellation_error = ex
+                for task in running_tasks:
+                    task.cancel(*ex.args)
+            on_completed_fut = None
+        if __debug__ and unhandled_exceptions:
+            # If run_one_coro raises an unhandled exception, it's probably a
+            # programming error, and I want to see it.
+            raise ExceptionGroup("staggered race failed", unhandled_exceptions)
+        if propagate_cancellation_error is not None:
+            raise propagate_cancellation_error
+        return winner_result, winner_index, exceptions
+    finally:
+        del exceptions, propagate_cancellation_error, unhandled_exceptions

Dependencies/Python/Lib/asyncio/streams.py

@@ -0,0 +1,787 @@
+__all__ = (
+    'StreamReader', 'StreamWriter', 'StreamReaderProtocol',
+    'open_connection', 'start_server')
+
+import collections
+import socket
+import sys
+import warnings
+import weakref
+
+if hasattr(socket, 'AF_UNIX'):
+    __all__ += ('open_unix_connection', 'start_unix_server')
+
+from . import coroutines
+from . import events
+from . import exceptions
+from . import format_helpers
+from . import protocols
+from .log import logger
+from .tasks import sleep
+
+
+_DEFAULT_LIMIT = 2 ** 16  # 64 KiB
+
+
+async def open_connection(host=None, port=None, *,
+                          limit=_DEFAULT_LIMIT, **kwds):
+    """A wrapper for create_connection() returning a (reader, writer) pair.
+
+    The reader returned is a StreamReader instance; the writer is a
+    StreamWriter instance.
+
+    The arguments are all the usual arguments to create_connection()
+    except protocol_factory; most common are positional host and port,
+    with various optional keyword arguments following.
+
+    Additional optional keyword arguments are loop (to set the event loop
+    instance to use) and limit (to set the buffer limit passed to the
+    StreamReader).
+
+    (If you want to customize the StreamReader and/or
+    StreamReaderProtocol classes, just copy the code -- there's
+    really nothing special here except some convenience.)
+    """
+    loop = events.get_running_loop()
+    reader = StreamReader(limit=limit, loop=loop)
+    protocol = StreamReaderProtocol(reader, loop=loop)
+    transport, _ = await loop.create_connection(
+        lambda: protocol, host, port, **kwds)
+    writer = StreamWriter(transport, protocol, reader, loop)
+    return reader, writer
+
+
+async def start_server(client_connected_cb, host=None, port=None, *,
+                       limit=_DEFAULT_LIMIT, **kwds):
+    """Start a socket server, call back for each client connected.
+
+    The first parameter, `client_connected_cb`, takes two parameters:
+    client_reader, client_writer.  client_reader is a StreamReader
+    object, while client_writer is a StreamWriter object.  This
+    parameter can either be a plain callback function or a coroutine;
+    if it is a coroutine, it will be automatically converted into a
+    Task.
+
+    The rest of the arguments are all the usual arguments to
+    loop.create_server() except protocol_factory; most common are
+    positional host and port, with various optional keyword arguments
+    following.  The return value is the same as loop.create_server().
+
+    Additional optional keyword argument is limit (to set the buffer
+    limit passed to the StreamReader).
+
+    The return value is the same as loop.create_server(), i.e. a
+    Server object which can be used to stop the service.
+    """
+    loop = events.get_running_loop()
+
+    def factory():
+        reader = StreamReader(limit=limit, loop=loop)
+        protocol = StreamReaderProtocol(reader, client_connected_cb,
+                                        loop=loop)
+        return protocol
+
+    return await loop.create_server(factory, host, port, **kwds)
+
+
+if hasattr(socket, 'AF_UNIX'):
+    # UNIX Domain Sockets are supported on this platform
+
+    async def open_unix_connection(path=None, *,
+                                   limit=_DEFAULT_LIMIT, **kwds):
+        """Similar to `open_connection` but works with UNIX Domain Sockets."""
+        loop = events.get_running_loop()
+
+        reader = StreamReader(limit=limit, loop=loop)
+        protocol = StreamReaderProtocol(reader, loop=loop)
+        transport, _ = await loop.create_unix_connection(
+            lambda: protocol, path, **kwds)
+        writer = StreamWriter(transport, protocol, reader, loop)
+        return reader, writer
+
+    async def start_unix_server(client_connected_cb, path=None, *,
+                                limit=_DEFAULT_LIMIT, **kwds):
+        """Similar to `start_server` but works with UNIX Domain Sockets."""
+        loop = events.get_running_loop()
+
+        def factory():
+            reader = StreamReader(limit=limit, loop=loop)
+            protocol = StreamReaderProtocol(reader, client_connected_cb,
+                                            loop=loop)
+            return protocol
+
+        return await loop.create_unix_server(factory, path, **kwds)
+
+
+class FlowControlMixin(protocols.Protocol):
+    """Reusable flow control logic for StreamWriter.drain().
+
+    This implements the protocol methods pause_writing(),
+    resume_writing() and connection_lost().  If the subclass overrides
+    these it must call the super methods.
+
+    StreamWriter.drain() must wait for _drain_helper() coroutine.
+    """
+
+    def __init__(self, loop=None):
+        if loop is None:
+            self._loop = events.get_event_loop()
+        else:
+            self._loop = loop
+        self._paused = False
+        self._drain_waiters = collections.deque()
+        self._connection_lost = False
+
+    def pause_writing(self):
+        assert not self._paused
+        self._paused = True
+        if self._loop.get_debug():
+            logger.debug("%r pauses writing", self)
+
+    def resume_writing(self):
+        assert self._paused
+        self._paused = False
+        if self._loop.get_debug():
+            logger.debug("%r resumes writing", self)
+
+        for waiter in self._drain_waiters:
+            if not waiter.done():
+                waiter.set_result(None)
+
+    def connection_lost(self, exc):
+        self._connection_lost = True
+        # Wake up the writer(s) if currently paused.
+        if not self._paused:
+            return
+
+        for waiter in self._drain_waiters:
+            if not waiter.done():
+                if exc is None:
+                    waiter.set_result(None)
+                else:
+                    waiter.set_exception(exc)
+
+    async def _drain_helper(self):
+        if self._connection_lost:
+            raise ConnectionResetError('Connection lost')
+        if not self._paused:
+            return
+        waiter = self._loop.create_future()
+        self._drain_waiters.append(waiter)
+        try:
+            await waiter
+        finally:
+            self._drain_waiters.remove(waiter)
+
+    def _get_close_waiter(self, stream):
+        raise NotImplementedError
+
+
+class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
+    """Helper class to adapt between Protocol and StreamReader.
+
+    (This is a helper class instead of making StreamReader itself a
+    Protocol subclass, because the StreamReader has other potential
+    uses, and to prevent the user of the StreamReader to accidentally
+    call inappropriate methods of the protocol.)
+    """
+
+    _source_traceback = None
+
+    def __init__(self, stream_reader, client_connected_cb=None, loop=None):
+        super().__init__(loop=loop)
+        if stream_reader is not None:
+            self._stream_reader_wr = weakref.ref(stream_reader)
+            self._source_traceback = stream_reader._source_traceback
+        else:
+            self._stream_reader_wr = None
+        if client_connected_cb is not None:
+            # This is a stream created by the `create_server()` function.
+            # Keep a strong reference to the reader until a connection
+            # is established.
+            self._strong_reader = stream_reader
+        self._reject_connection = False
+        self._task = None
+        self._transport = None
+        self._client_connected_cb = client_connected_cb
+        self._over_ssl = False
+        self._closed = self._loop.create_future()
+
+    @property
+    def _stream_reader(self):
+        if self._stream_reader_wr is None:
+            return None
+        return self._stream_reader_wr()
+
+    def _replace_transport(self, transport):
+        loop = self._loop
+        self._transport = transport
+        self._over_ssl = transport.get_extra_info('sslcontext') is not None
+
+    def connection_made(self, transport):
+        if self._reject_connection:
+            context = {
+                'message': ('An open stream was garbage collected prior to '
+                            'establishing network connection; '
+                            'call "stream.close()" explicitly.')
+            }
+            if self._source_traceback:
+                context['source_traceback'] = self._source_traceback
+            self._loop.call_exception_handler(context)
+            transport.abort()
+            return
+        self._transport = transport
+        reader = self._stream_reader
+        if reader is not None:
+            reader.set_transport(transport)
+        self._over_ssl = transport.get_extra_info('sslcontext') is not None
+        if self._client_connected_cb is not None:
+            writer = StreamWriter(transport, self, reader, self._loop)
+            res = self._client_connected_cb(reader, writer)
+            if coroutines.iscoroutine(res):
+                def callback(task):
+                    if task.cancelled():
+                        transport.close()
+                        return
+                    exc = task.exception()
+                    if exc is not None:
+                        self._loop.call_exception_handler({
+                            'message': 'Unhandled exception in client_connected_cb',
+                            'exception': exc,
+                            'transport': transport,
+                        })
+                        transport.close()
+
+                self._task = self._loop.create_task(res)
+                self._task.add_done_callback(callback)
+
+            self._strong_reader = None
+
+    def connection_lost(self, exc):
+        reader = self._stream_reader
+        if reader is not None:
+            if exc is None:
+                reader.feed_eof()
+            else:
+                reader.set_exception(exc)
+        if not self._closed.done():
+            if exc is None:
+                self._closed.set_result(None)
+            else:
+                self._closed.set_exception(exc)
+        super().connection_lost(exc)
+        self._stream_reader_wr = None
+        self._stream_writer = None
+        self._task = None
+        self._transport = None
+
+    def data_received(self, data):
+        reader = self._stream_reader
+        if reader is not None:
+            reader.feed_data(data)
+
+    def eof_received(self):
+        reader = self._stream_reader
+        if reader is not None:
+            reader.feed_eof()
+        if self._over_ssl:
+            # Prevent a warning in SSLProtocol.eof_received:
+            # "returning true from eof_received()
+            # has no effect when using ssl"
+            return False
+        return True
+
+    def _get_close_waiter(self, stream):
+        return self._closed
+
+    def __del__(self):
+        # Prevent reports about unhandled exceptions.
+        # Better than self._closed._log_traceback = False hack
+        try:
+            closed = self._closed
+        except AttributeError:
+            pass  # failed constructor
+        else:
+            if closed.done() and not closed.cancelled():
+                closed.exception()
+
+
+class StreamWriter:
+    """Wraps a Transport.
+
+    This exposes write(), writelines(), [can_]write_eof(),
+    get_extra_info() and close().  It adds drain() which returns an
+    optional Future on which you can wait for flow control.  It also
+    adds a transport property which references the Transport
+    directly.
+    """
+
+    def __init__(self, transport, protocol, reader, loop):
+        self._transport = transport
+        self._protocol = protocol
+        # drain() expects that the reader has an exception() method
+        assert reader is None or isinstance(reader, StreamReader)
+        self._reader = reader
+        self._loop = loop
+        self._complete_fut = self._loop.create_future()
+        self._complete_fut.set_result(None)
+
+    def __repr__(self):
+        info = [self.__class__.__name__, f'transport={self._transport!r}']
+        if self._reader is not None:
+            info.append(f'reader={self._reader!r}')
+        return '<{}>'.format(' '.join(info))
+
+    @property
+    def transport(self):
+        return self._transport
+
+    def write(self, data):
+        self._transport.write(data)
+
+    def writelines(self, data):
+        self._transport.writelines(data)
+
+    def write_eof(self):
+        return self._transport.write_eof()
+
+    def can_write_eof(self):
+        return self._transport.can_write_eof()
+
+    def close(self):
+        return self._transport.close()
+
+    def is_closing(self):
+        return self._transport.is_closing()
+
+    async def wait_closed(self):
+        await self._protocol._get_close_waiter(self)
+
+    def get_extra_info(self, name, default=None):
+        return self._transport.get_extra_info(name, default)
+
+    async def drain(self):
+        """Flush the write buffer.
+
+        The intended use is to write
+
+          w.write(data)
+          await w.drain()
+        """
+        if self._reader is not None:
+            exc = self._reader.exception()
+            if exc is not None:
+                raise exc
+        if self._transport.is_closing():
+            # Wait for protocol.connection_lost() call
+            # Raise connection closing error if any,
+            # ConnectionResetError otherwise
+            # Yield to the event loop so connection_lost() may be
+            # called.  Without this, _drain_helper() would return
+            # immediately, and code that calls
+            #     write(...); await drain()
+            # in a loop would never call connection_lost(), so it
+            # would not see an error when the socket is closed.
+            await sleep(0)
+        await self._protocol._drain_helper()
+
+    async def start_tls(self, sslcontext, *,
+                        server_hostname=None,
+                        ssl_handshake_timeout=None,
+                        ssl_shutdown_timeout=None):
+        """Upgrade an existing stream-based connection to TLS."""
+        server_side = self._protocol._client_connected_cb is not None
+        protocol = self._protocol
+        await self.drain()
+        new_transport = await self._loop.start_tls(  # type: ignore
+            self._transport, protocol, sslcontext,
+            server_side=server_side, server_hostname=server_hostname,
+            ssl_handshake_timeout=ssl_handshake_timeout,
+            ssl_shutdown_timeout=ssl_shutdown_timeout)
+        self._transport = new_transport
+        protocol._replace_transport(new_transport)
+
+    def __del__(self, warnings=warnings):
+        if not self._transport.is_closing():
+            if self._loop.is_closed():
+                warnings.warn("loop is closed", ResourceWarning)
+            else:
+                self.close()
+                warnings.warn(f"unclosed {self!r}", ResourceWarning)
+
+class StreamReader:
+
+    _source_traceback = None
+
+    def __init__(self, limit=_DEFAULT_LIMIT, loop=None):
+        # The line length limit is  a security feature;
+        # it also doubles as half the buffer limit.
+
+        if limit <= 0:
+            raise ValueError('Limit cannot be <= 0')
+
+        self._limit = limit
+        if loop is None:
+            self._loop = events.get_event_loop()
+        else:
+            self._loop = loop
+        self._buffer = bytearray()
+        self._eof = False    # Whether we're done.
+        self._waiter = None  # A future used by _wait_for_data()
+        self._exception = None
+        self._transport = None
+        self._paused = False
+        if self._loop.get_debug():
+            self._source_traceback = format_helpers.extract_stack(
+                sys._getframe(1))
+
+    def __repr__(self):
+        info = ['StreamReader']
+        if self._buffer:
+            info.append(f'{len(self._buffer)} bytes')
+        if self._eof:
+            info.append('eof')
+        if self._limit != _DEFAULT_LIMIT:
+            info.append(f'limit={self._limit}')
+        if self._waiter:
+            info.append(f'waiter={self._waiter!r}')
+        if self._exception:
+            info.append(f'exception={self._exception!r}')
+        if self._transport:
+            info.append(f'transport={self._transport!r}')
+        if self._paused:
+            info.append('paused')
+        return '<{}>'.format(' '.join(info))
+
+    def exception(self):
+        return self._exception
+
+    def set_exception(self, exc):
+        self._exception = exc
+
+        waiter = self._waiter
+        if waiter is not None:
+            self._waiter = None
+            if not waiter.cancelled():
+                waiter.set_exception(exc)
+
+    def _wakeup_waiter(self):
+        """Wakeup read*() functions waiting for data or EOF."""
+        waiter = self._waiter
+        if waiter is not None:
+            self._waiter = None
+            if not waiter.cancelled():
+                waiter.set_result(None)
+
+    def set_transport(self, transport):
+        assert self._transport is None, 'Transport already set'
+        self._transport = transport
+
+    def _maybe_resume_transport(self):
+        if self._paused and len(self._buffer) <= self._limit:
+            self._paused = False
+            self._transport.resume_reading()
+
+    def feed_eof(self):
+        self._eof = True
+        self._wakeup_waiter()
+
+    def at_eof(self):
+        """Return True if the buffer is empty and 'feed_eof' was called."""
+        return self._eof and not self._buffer
+
+    def feed_data(self, data):
+        assert not self._eof, 'feed_data after feed_eof'
+
+        if not data:
+            return
+
+        self._buffer.extend(data)
+        self._wakeup_waiter()
+
+        if (self._transport is not None and
+                not self._paused and
+                len(self._buffer) > 2 * self._limit):
+            try:
+                self._transport.pause_reading()
+            except NotImplementedError:
+                # The transport can't be paused.
+                # We'll just have to buffer all data.
+                # Forget the transport so we don't keep trying.
+                self._transport = None
+            else:
+                self._paused = True
+
+    async def _wait_for_data(self, func_name):
+        """Wait until feed_data() or feed_eof() is called.
+
+        If stream was paused, automatically resume it.
+        """
+        # StreamReader uses a future to link the protocol feed_data() method
+        # to a read coroutine. Running two read coroutines at the same time
+        # would have an unexpected behaviour. It would not possible to know
+        # which coroutine would get the next data.
+        if self._waiter is not None:
+            raise RuntimeError(
+                f'{func_name}() called while another coroutine is '
+                f'already waiting for incoming data')
+
+        assert not self._eof, '_wait_for_data after EOF'
+
+        # Waiting for data while paused will make deadlock, so prevent it.
+        # This is essential for readexactly(n) for case when n > self._limit.
+        if self._paused:
+            self._paused = False
+            self._transport.resume_reading()
+
+        self._waiter = self._loop.create_future()
+        try:
+            await self._waiter
+        finally:
+            self._waiter = None
+
+    async def readline(self):
+        """Read chunk of data from the stream until newline (b'\n') is found.
+
+        On success, return chunk that ends with newline. If only partial
+        line can be read due to EOF, return incomplete line without
+        terminating newline. When EOF was reached while no bytes read, empty
+        bytes object is returned.
+
+        If limit is reached, ValueError will be raised. In that case, if
+        newline was found, complete line including newline will be removed
+        from internal buffer. Else, internal buffer will be cleared. Limit is
+        compared against part of the line without newline.
+
+        If stream was paused, this function will automatically resume it if
+        needed.
+        """
+        sep = b'\n'
+        seplen = len(sep)
+        try:
+            line = await self.readuntil(sep)
+        except exceptions.IncompleteReadError as e:
+            return e.partial
+        except exceptions.LimitOverrunError as e:
+            if self._buffer.startswith(sep, e.consumed):
+                del self._buffer[:e.consumed + seplen]
+            else:
+                self._buffer.clear()
+            self._maybe_resume_transport()
+            raise ValueError(e.args[0])
+        return line
+
+    async def readuntil(self, separator=b'\n'):
+        """Read data from the stream until ``separator`` is found.
+
+        On success, the data and separator will be removed from the
+        internal buffer (consumed). Returned data will include the
+        separator at the end.
+
+        Configured stream limit is used to check result. Limit sets the
+        maximal length of data that can be returned, not counting the
+        separator.
+
+        If an EOF occurs and the complete separator is still not found,
+        an IncompleteReadError exception will be raised, and the internal
+        buffer will be reset.  The IncompleteReadError.partial attribute
+        may contain the separator partially.
+
+        If the data cannot be read because of over limit, a
+        LimitOverrunError exception  will be raised, and the data
+        will be left in the internal buffer, so it can be read again.
+
+        The ``separator`` may also be a tuple of separators. In this
+        case the return value will be the shortest possible that has any
+        separator as the suffix. For the purposes of LimitOverrunError,
+        the shortest possible separator is considered to be the one that
+        matched.
+        """
+        if isinstance(separator, tuple):
+            # Makes sure shortest matches wins
+            separator = sorted(separator, key=len)
+        else:
+            separator = [separator]
+        if not separator:
+            raise ValueError('Separator should contain at least one element')
+        min_seplen = len(separator[0])
+        max_seplen = len(separator[-1])
+        if min_seplen == 0:
+            raise ValueError('Separator should be at least one-byte string')
+
+        if self._exception is not None:
+            raise self._exception
+
+        # Consume whole buffer except last bytes, which length is
+        # one less than max_seplen. Let's check corner cases with
+        # separator[-1]='SEPARATOR':
+        # * we have received almost complete separator (without last
+        #   byte). i.e buffer='some textSEPARATO'. In this case we
+        #   can safely consume max_seplen - 1 bytes.
+        # * last byte of buffer is first byte of separator, i.e.
+        #   buffer='abcdefghijklmnopqrS'. We may safely consume
+        #   everything except that last byte, but this require to
+        #   analyze bytes of buffer that match partial separator.
+        #   This is slow and/or require FSM. For this case our
+        #   implementation is not optimal, since require rescanning
+        #   of data that is known to not belong to separator. In
+        #   real world, separator will not be so long to notice
+        #   performance problems. Even when reading MIME-encoded
+        #   messages :)
+
+        # `offset` is the number of bytes from the beginning of the buffer
+        # where there is no occurrence of any `separator`.
+        offset = 0
+
+        # Loop until we find a `separator` in the buffer, exceed the buffer size,
+        # or an EOF has happened.
+        while True:
+            buflen = len(self._buffer)
+
+            # Check if we now have enough data in the buffer for shortest
+            # separator to fit.
+            if buflen - offset >= min_seplen:
+                match_start = None
+                match_end = None
+                for sep in separator:
+                    isep = self._buffer.find(sep, offset)
+
+                    if isep != -1:
+                        # `separator` is in the buffer. `match_start` and
+                        # `match_end` will be used later to retrieve the
+                        # data.
+                        end = isep + len(sep)
+                        if match_end is None or end < match_end:
+                            match_end = end
+                            match_start = isep
+                if match_end is not None:
+                    break
+
+                # see upper comment for explanation.
+                offset = max(0, buflen + 1 - max_seplen)
+                if offset > self._limit:
+                    raise exceptions.LimitOverrunError(
+                        'Separator is not found, and chunk exceed the limit',
+                        offset)
+
+            # Complete message (with full separator) may be present in buffer
+            # even when EOF flag is set. This may happen when the last chunk
+            # adds data which makes separator be found. That's why we check for
+            # EOF *after* inspecting the buffer.
+            if self._eof:
+                chunk = bytes(self._buffer)
+                self._buffer.clear()
+                raise exceptions.IncompleteReadError(chunk, None)
+
+            # _wait_for_data() will resume reading if stream was paused.
+            await self._wait_for_data('readuntil')
+
+        if match_start > self._limit:
+            raise exceptions.LimitOverrunError(
+                'Separator is found, but chunk is longer than limit', match_start)
+
+        chunk = self._buffer[:match_end]
+        del self._buffer[:match_end]
+        self._maybe_resume_transport()
+        return bytes(chunk)
+
+    async def read(self, n=-1):
+        """Read up to `n` bytes from the stream.
+
+        If `n` is not provided or set to -1,
+        read until EOF, then return all read bytes.
+        If EOF was received and the internal buffer is empty,
+        return an empty bytes object.
+
+        If `n` is 0, return an empty bytes object immediately.
+
+        If `n` is positive, return at most `n` available bytes
+        as soon as at least 1 byte is available in the internal buffer.
+        If EOF is received before any byte is read, return an empty
+        bytes object.
+
+        Returned value is not limited with limit, configured at stream
+        creation.
+
+        If stream was paused, this function will automatically resume it if
+        needed.
+        """
+
+        if self._exception is not None:
+            raise self._exception
+
+        if n == 0:
+            return b''
+
+        if n < 0:
+            # This used to just loop creating a new waiter hoping to
+            # collect everything in self._buffer, but that would
+            # deadlock if the subprocess sends more than self.limit
+            # bytes.  So just call self.read(self._limit) until EOF.
+            blocks = []
+            while True:
+                block = await self.read(self._limit)
+                if not block:
+                    break
+                blocks.append(block)
+            return b''.join(blocks)
+
+        if not self._buffer and not self._eof:
+            await self._wait_for_data('read')
+
+        # This will work right even if buffer is less than n bytes
+        data = bytes(memoryview(self._buffer)[:n])
+        del self._buffer[:n]
+
+        self._maybe_resume_transport()
+        return data
+
+    async def readexactly(self, n):
+        """Read exactly `n` bytes.
+
+        Raise an IncompleteReadError if EOF is reached before `n` bytes can be
+        read. The IncompleteReadError.partial attribute of the exception will
+        contain the partial read bytes.
+
+        if n is zero, return empty bytes object.
+
+        Returned value is not limited with limit, configured at stream
+        creation.
+
+        If stream was paused, this function will automatically resume it if
+        needed.
+        """
+        if n < 0:
+            raise ValueError('readexactly size can not be less than zero')
+
+        if self._exception is not None:
+            raise self._exception
+
+        if n == 0:
+            return b''
+
+        while len(self._buffer) < n:
+            if self._eof:
+                incomplete = bytes(self._buffer)
+                self._buffer.clear()
+                raise exceptions.IncompleteReadError(incomplete, n)
+
+            await self._wait_for_data('readexactly')
+
+        if len(self._buffer) == n:
+            data = bytes(self._buffer)
+            self._buffer.clear()
+        else:
+            data = bytes(memoryview(self._buffer)[:n])
+            del self._buffer[:n]
+        self._maybe_resume_transport()
+        return data
+
+    def __aiter__(self):
+        return self
+
+    async def __anext__(self):
+        val = await self.readline()
+        if val == b'':
+            raise StopAsyncIteration
+        return val

Dependencies/Python/Lib/asyncio/subprocess.py

@@ -0,0 +1,229 @@
+__all__ = 'create_subprocess_exec', 'create_subprocess_shell'
+
+import subprocess
+
+from . import events
+from . import protocols
+from . import streams
+from . import tasks
+from .log import logger
+
+
+PIPE = subprocess.PIPE
+STDOUT = subprocess.STDOUT
+DEVNULL = subprocess.DEVNULL
+
+
+class SubprocessStreamProtocol(streams.FlowControlMixin,
+                               protocols.SubprocessProtocol):
+    """Like StreamReaderProtocol, but for a subprocess."""
+
+    def __init__(self, limit, loop):
+        super().__init__(loop=loop)
+        self._limit = limit
+        self.stdin = self.stdout = self.stderr = None
+        self._transport = None
+        self._process_exited = False
+        self._pipe_fds = []
+        self._stdin_closed = self._loop.create_future()
+
+    def __repr__(self):
+        info = [self.__class__.__name__]
+        if self.stdin is not None:
+            info.append(f'stdin={self.stdin!r}')
+        if self.stdout is not None:
+            info.append(f'stdout={self.stdout!r}')
+        if self.stderr is not None:
+            info.append(f'stderr={self.stderr!r}')
+        return '<{}>'.format(' '.join(info))
+
+    def connection_made(self, transport):
+        self._transport = transport
+
+        stdout_transport = transport.get_pipe_transport(1)
+        if stdout_transport is not None:
+            self.stdout = streams.StreamReader(limit=self._limit,
+                                               loop=self._loop)
+            self.stdout.set_transport(stdout_transport)
+            self._pipe_fds.append(1)
+
+        stderr_transport = transport.get_pipe_transport(2)
+        if stderr_transport is not None:
+            self.stderr = streams.StreamReader(limit=self._limit,
+                                               loop=self._loop)
+            self.stderr.set_transport(stderr_transport)
+            self._pipe_fds.append(2)
+
+        stdin_transport = transport.get_pipe_transport(0)
+        if stdin_transport is not None:
+            self.stdin = streams.StreamWriter(stdin_transport,
+                                              protocol=self,
+                                              reader=None,
+                                              loop=self._loop)
+
+    def pipe_data_received(self, fd, data):
+        if fd == 1:
+            reader = self.stdout
+        elif fd == 2:
+            reader = self.stderr
+        else:
+            reader = None
+        if reader is not None:
+            reader.feed_data(data)
+
+    def pipe_connection_lost(self, fd, exc):
+        if fd == 0:
+            pipe = self.stdin
+            if pipe is not None:
+                pipe.close()
+            self.connection_lost(exc)
+            if exc is None:
+                self._stdin_closed.set_result(None)
+            else:
+                self._stdin_closed.set_exception(exc)
+                # Since calling `wait_closed()` is not mandatory,
+                # we shouldn't log the traceback if this is not awaited.
+                self._stdin_closed._log_traceback = False
+            return
+        if fd == 1:
+            reader = self.stdout
+        elif fd == 2:
+            reader = self.stderr
+        else:
+            reader = None
+        if reader is not None:
+            if exc is None:
+                reader.feed_eof()
+            else:
+                reader.set_exception(exc)
+
+        if fd in self._pipe_fds:
+            self._pipe_fds.remove(fd)
+        self._maybe_close_transport()
+
+    def process_exited(self):
+        self._process_exited = True
+        self._maybe_close_transport()
+
+    def _maybe_close_transport(self):
+        if len(self._pipe_fds) == 0 and self._process_exited:
+            self._transport.close()
+            self._transport = None
+
+    def _get_close_waiter(self, stream):
+        if stream is self.stdin:
+            return self._stdin_closed
+
+
+class Process:
+    def __init__(self, transport, protocol, loop):
+        self._transport = transport
+        self._protocol = protocol
+        self._loop = loop
+        self.stdin = protocol.stdin
+        self.stdout = protocol.stdout
+        self.stderr = protocol.stderr
+        self.pid = transport.get_pid()
+
+    def __repr__(self):
+        return f'<{self.__class__.__name__} {self.pid}>'
+
+    @property
+    def returncode(self):
+        return self._transport.get_returncode()
+
+    async def wait(self):
+        """Wait until the process exit and return the process return code."""
+        return await self._transport._wait()
+
+    def send_signal(self, signal):
+        self._transport.send_signal(signal)
+
+    def terminate(self):
+        self._transport.terminate()
+
+    def kill(self):
+        self._transport.kill()
+
+    async def _feed_stdin(self, input):
+        debug = self._loop.get_debug()
+        try:
+            if input is not None:
+                self.stdin.write(input)
+                if debug:
+                    logger.debug(
+                        '%r communicate: feed stdin (%s bytes)', self, len(input))
+
+            await self.stdin.drain()
+        except (BrokenPipeError, ConnectionResetError) as exc:
+            # communicate() ignores BrokenPipeError and ConnectionResetError.
+            # write() and drain() can raise these exceptions.
+            if debug:
+                logger.debug('%r communicate: stdin got %r', self, exc)
+
+        if debug:
+            logger.debug('%r communicate: close stdin', self)
+        self.stdin.close()
+
+    async def _noop(self):
+        return None
+
+    async def _read_stream(self, fd):
+        transport = self._transport.get_pipe_transport(fd)
+        if fd == 2:
+            stream = self.stderr
+        else:
+            assert fd == 1
+            stream = self.stdout
+        if self._loop.get_debug():
+            name = 'stdout' if fd == 1 else 'stderr'
+            logger.debug('%r communicate: read %s', self, name)
+        output = await stream.read()
+        if self._loop.get_debug():
+            name = 'stdout' if fd == 1 else 'stderr'
+            logger.debug('%r communicate: close %s', self, name)
+        transport.close()
+        return output
+
+    async def communicate(self, input=None):
+        if self.stdin is not None:
+            stdin = self._feed_stdin(input)
+        else:
+            stdin = self._noop()
+        if self.stdout is not None:
+            stdout = self._read_stream(1)
+        else:
+            stdout = self._noop()
+        if self.stderr is not None:
+            stderr = self._read_stream(2)
+        else:
+            stderr = self._noop()
+        stdin, stdout, stderr = await tasks.gather(stdin, stdout, stderr)
+        await self.wait()
+        return (stdout, stderr)
+
+
+async def create_subprocess_shell(cmd, stdin=None, stdout=None, stderr=None,
+                                  limit=streams._DEFAULT_LIMIT, **kwds):
+    loop = events.get_running_loop()
+    protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
+                                                        loop=loop)
+    transport, protocol = await loop.subprocess_shell(
+        protocol_factory,
+        cmd, stdin=stdin, stdout=stdout,
+        stderr=stderr, **kwds)
+    return Process(transport, protocol, loop)
+
+
+async def create_subprocess_exec(program, *args, stdin=None, stdout=None,
+                                 stderr=None, limit=streams._DEFAULT_LIMIT,
+                                 **kwds):
+    loop = events.get_running_loop()
+    protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
+                                                        loop=loop)
+    transport, protocol = await loop.subprocess_exec(
+        protocol_factory,
+        program, *args,
+        stdin=stdin, stdout=stdout,
+        stderr=stderr, **kwds)
+    return Process(transport, protocol, loop)

Dependencies/Python/Lib/asyncio/taskgroups.py

@@ -0,0 +1,278 @@
+# Adapted with permission from the EdgeDB project;
+# license: PSFL.
+
+
+__all__ = ("TaskGroup",)
+
+from . import events
+from . import exceptions
+from . import tasks
+
+
+class TaskGroup:
+    """Asynchronous context manager for managing groups of tasks.
+
+    Example use:
+
+        async with asyncio.TaskGroup() as group:
+            task1 = group.create_task(some_coroutine(...))
+            task2 = group.create_task(other_coroutine(...))
+        print("Both tasks have completed now.")
+
+    All tasks are awaited when the context manager exits.
+
+    Any exceptions other than `asyncio.CancelledError` raised within
+    a task will cancel all remaining tasks and wait for them to exit.
+    The exceptions are then combined and raised as an `ExceptionGroup`.
+    """
+    def __init__(self):
+        self._entered = False
+        self._exiting = False
+        self._aborting = False
+        self._loop = None
+        self._parent_task = None
+        self._parent_cancel_requested = False
+        self._tasks = set()
+        self._errors = []
+        self._base_error = None
+        self._on_completed_fut = None
+
+    def __repr__(self):
+        info = ['']
+        if self._tasks:
+            info.append(f'tasks={len(self._tasks)}')
+        if self._errors:
+            info.append(f'errors={len(self._errors)}')
+        if self._aborting:
+            info.append('cancelling')
+        elif self._entered:
+            info.append('entered')
+
+        info_str = ' '.join(info)
+        return f'<TaskGroup{info_str}>'
+
+    async def __aenter__(self):
+        if self._entered:
+            raise RuntimeError(
+                f"TaskGroup {self!r} has already been entered")
+        if self._loop is None:
+            self._loop = events.get_running_loop()
+        self._parent_task = tasks.current_task(self._loop)
+        if self._parent_task is None:
+            raise RuntimeError(
+                f'TaskGroup {self!r} cannot determine the parent task')
+        self._entered = True
+
+        return self
+
+    async def __aexit__(self, et, exc, tb):
+        tb = None
+        try:
+            return await self._aexit(et, exc)
+        finally:
+            # Exceptions are heavy objects that can have object
+            # cycles (bad for GC); let's not keep a reference to
+            # a bunch of them. It would be nicer to use a try/finally
+            # in __aexit__ directly but that introduced some diff noise
+            self._parent_task = None
+            self._errors = None
+            self._base_error = None
+            exc = None
+
+    async def _aexit(self, et, exc):
+        self._exiting = True
+
+        if (exc is not None and
+                self._is_base_error(exc) and
+                self._base_error is None):
+            self._base_error = exc
+
+        if et is not None and issubclass(et, exceptions.CancelledError):
+            propagate_cancellation_error = exc
+        else:
+            propagate_cancellation_error = None
+
+        if et is not None:
+            if not self._aborting:
+                # Our parent task is being cancelled:
+                #
+                #    async with TaskGroup() as g:
+                #        g.create_task(...)
+                #        await ...  # <- CancelledError
+                #
+                # or there's an exception in "async with":
+                #
+                #    async with TaskGroup() as g:
+                #        g.create_task(...)
+                #        1 / 0
+                #
+                self._abort()
+
+        # We use while-loop here because "self._on_completed_fut"
+        # can be cancelled multiple times if our parent task
+        # is being cancelled repeatedly (or even once, when
+        # our own cancellation is already in progress)
+        while self._tasks:
+            if self._on_completed_fut is None:
+                self._on_completed_fut = self._loop.create_future()
+
+            try:
+                await self._on_completed_fut
+            except exceptions.CancelledError as ex:
+                if not self._aborting:
+                    # Our parent task is being cancelled:
+                    #
+                    #    async def wrapper():
+                    #        async with TaskGroup() as g:
+                    #            g.create_task(foo)
+                    #
+                    # "wrapper" is being cancelled while "foo" is
+                    # still running.
+                    propagate_cancellation_error = ex
+                    self._abort()
+
+            self._on_completed_fut = None
+
+        assert not self._tasks
+
+        if self._base_error is not None:
+            try:
+                raise self._base_error
+            finally:
+                exc = None
+
+        if self._parent_cancel_requested:
+            # If this flag is set we *must* call uncancel().
+            if self._parent_task.uncancel() == 0:
+                # If there are no pending cancellations left,
+                # don't propagate CancelledError.
+                propagate_cancellation_error = None
+
+        # Propagate CancelledError if there is one, except if there
+        # are other errors -- those have priority.
+        try:
+            if propagate_cancellation_error is not None and not self._errors:
+                try:
+                    raise propagate_cancellation_error
+                finally:
+                    exc = None
+        finally:
+            propagate_cancellation_error = None
+
+        if et is not None and not issubclass(et, exceptions.CancelledError):
+            self._errors.append(exc)
+
+        if self._errors:
+            # If the parent task is being cancelled from the outside
+            # of the taskgroup, un-cancel and re-cancel the parent task,
+            # which will keep the cancel count stable.
+            if self._parent_task.cancelling():
+                self._parent_task.uncancel()
+                self._parent_task.cancel()
+            try:
+                raise BaseExceptionGroup(
+                    'unhandled errors in a TaskGroup',
+                    self._errors,
+                ) from None
+            finally:
+                exc = None
+
+
+    def create_task(self, coro, *, name=None, context=None):
+        """Create a new task in this group and return it.
+
+        Similar to `asyncio.create_task`.
+        """
+        if not self._entered:
+            coro.close()
+            raise RuntimeError(f"TaskGroup {self!r} has not been entered")
+        if self._exiting and not self._tasks:
+            coro.close()
+            raise RuntimeError(f"TaskGroup {self!r} is finished")
+        if self._aborting:
+            coro.close()
+            raise RuntimeError(f"TaskGroup {self!r} is shutting down")
+        if context is None:
+            task = self._loop.create_task(coro, name=name)
+        else:
+            task = self._loop.create_task(coro, name=name, context=context)
+
+        # Always schedule the done callback even if the task is
+        # already done (e.g. if the coro was able to complete eagerly),
+        # otherwise if the task completes with an exception then it will cancel
+        # the current task too early. gh-128550, gh-128588
+        self._tasks.add(task)
+        task.add_done_callback(self._on_task_done)
+        try:
+            return task
+        finally:
+            # gh-128552: prevent a refcycle of
+            # task.exception().__traceback__->TaskGroup.create_task->task
+            del task
+
+    # Since Python 3.8 Tasks propagate all exceptions correctly,
+    # except for KeyboardInterrupt and SystemExit which are
+    # still considered special.
+
+    def _is_base_error(self, exc: BaseException) -> bool:
+        assert isinstance(exc, BaseException)
+        return isinstance(exc, (SystemExit, KeyboardInterrupt))
+
+    def _abort(self):
+        self._aborting = True
+
+        for t in self._tasks:
+            if not t.done():
+                t.cancel()
+
+    def _on_task_done(self, task):
+        self._tasks.discard(task)
+
+        if self._on_completed_fut is not None and not self._tasks:
+            if not self._on_completed_fut.done():
+                self._on_completed_fut.set_result(True)
+
+        if task.cancelled():
+            return
+
+        exc = task.exception()
+        if exc is None:
+            return
+
+        self._errors.append(exc)
+        if self._is_base_error(exc) and self._base_error is None:
+            self._base_error = exc
+
+        if self._parent_task.done():
+            # Not sure if this case is possible, but we want to handle
+            # it anyways.
+            self._loop.call_exception_handler({
+                'message': f'Task {task!r} has errored out but its parent '
+                           f'task {self._parent_task} is already completed',
+                'exception': exc,
+                'task': task,
+            })
+            return
+
+        if not self._aborting and not self._parent_cancel_requested:
+            # If parent task *is not* being cancelled, it means that we want
+            # to manually cancel it to abort whatever is being run right now
+            # in the TaskGroup.  But we want to mark parent task as
+            # "not cancelled" later in __aexit__.  Example situation that
+            # we need to handle:
+            #
+            #    async def foo():
+            #        try:
+            #            async with TaskGroup() as g:
+            #                g.create_task(crash_soon())
+            #                await something  # <- this needs to be canceled
+            #                                 #    by the TaskGroup, e.g.
+            #                                 #    foo() needs to be cancelled
+            #        except Exception:
+            #            # Ignore any exceptions raised in the TaskGroup
+            #            pass
+            #        await something_else     # this line has to be called
+            #                                 # after TaskGroup is finished.
+            self._abort()
+            self._parent_cancel_requested = True
+            self._parent_task.cancel()

Dependencies/Python/Lib/asyncio/threads.py

@@ -0,0 +1,25 @@
+"""High-level support for working with threads in asyncio"""
+
+import functools
+import contextvars
+
+from . import events
+
+
+__all__ = "to_thread",
+
+
+async def to_thread(func, /, *args, **kwargs):
+    """Asynchronously run function *func* in a separate thread.
+
+    Any *args and **kwargs supplied for this function are directly passed
+    to *func*. Also, the current :class:`contextvars.Context` is propagated,
+    allowing context variables from the main thread to be accessed in the
+    separate thread.
+
+    Return a coroutine that can be awaited to get the eventual result of *func*.
+    """
+    loop = events.get_running_loop()
+    ctx = contextvars.copy_context()
+    func_call = functools.partial(ctx.run, func, *args, **kwargs)
+    return await loop.run_in_executor(None, func_call)

Dependencies/Python/Lib/asyncio/timeouts.py

@@ -0,0 +1,184 @@
+import enum
+
+from types import TracebackType
+from typing import final, Optional, Type
+
+from . import events
+from . import exceptions
+from . import tasks
+
+
+__all__ = (
+    "Timeout",
+    "timeout",
+    "timeout_at",
+)
+
+
+class _State(enum.Enum):
+    CREATED = "created"
+    ENTERED = "active"
+    EXPIRING = "expiring"
+    EXPIRED = "expired"
+    EXITED = "finished"
+
+
+@final
+class Timeout:
+    """Asynchronous context manager for cancelling overdue coroutines.
+
+    Use `timeout()` or `timeout_at()` rather than instantiating this class directly.
+    """
+
+    def __init__(self, when: Optional[float]) -> None:
+        """Schedule a timeout that will trigger at a given loop time.
+
+        - If `when` is `None`, the timeout will never trigger.
+        - If `when < loop.time()`, the timeout will trigger on the next
+          iteration of the event loop.
+        """
+        self._state = _State.CREATED
+
+        self._timeout_handler: Optional[events.TimerHandle] = None
+        self._task: Optional[tasks.Task] = None
+        self._when = when
+
+    def when(self) -> Optional[float]:
+        """Return the current deadline."""
+        return self._when
+
+    def reschedule(self, when: Optional[float]) -> None:
+        """Reschedule the timeout."""
+        if self._state is not _State.ENTERED:
+            if self._state is _State.CREATED:
+                raise RuntimeError("Timeout has not been entered")
+            raise RuntimeError(
+                f"Cannot change state of {self._state.value} Timeout",
+            )
+
+        self._when = when
+
+        if self._timeout_handler is not None:
+            self._timeout_handler.cancel()
+
+        if when is None:
+            self._timeout_handler = None
+        else:
+            loop = events.get_running_loop()
+            if when <= loop.time():
+                self._timeout_handler = loop.call_soon(self._on_timeout)
+            else:
+                self._timeout_handler = loop.call_at(when, self._on_timeout)
+
+    def expired(self) -> bool:
+        """Is timeout expired during execution?"""
+        return self._state in (_State.EXPIRING, _State.EXPIRED)
+
+    def __repr__(self) -> str:
+        info = ['']
+        if self._state is _State.ENTERED:
+            when = round(self._when, 3) if self._when is not None else None
+            info.append(f"when={when}")
+        info_str = ' '.join(info)
+        return f"<Timeout [{self._state.value}]{info_str}>"
+
+    async def __aenter__(self) -> "Timeout":
+        if self._state is not _State.CREATED:
+            raise RuntimeError("Timeout has already been entered")
+        task = tasks.current_task()
+        if task is None:
+            raise RuntimeError("Timeout should be used inside a task")
+        self._state = _State.ENTERED
+        self._task = task
+        self._cancelling = self._task.cancelling()
+        self.reschedule(self._when)
+        return self
+
+    async def __aexit__(
+        self,
+        exc_type: Optional[Type[BaseException]],
+        exc_val: Optional[BaseException],
+        exc_tb: Optional[TracebackType],
+    ) -> Optional[bool]:
+        assert self._state in (_State.ENTERED, _State.EXPIRING)
+
+        if self._timeout_handler is not None:
+            self._timeout_handler.cancel()
+            self._timeout_handler = None
+
+        if self._state is _State.EXPIRING:
+            self._state = _State.EXPIRED
+
+            if self._task.uncancel() <= self._cancelling and exc_type is not None:
+                # Since there are no new cancel requests, we're
+                # handling this.
+                if issubclass(exc_type, exceptions.CancelledError):
+                    raise TimeoutError from exc_val
+                elif exc_val is not None:
+                    self._insert_timeout_error(exc_val)
+                    if isinstance(exc_val, ExceptionGroup):
+                        for exc in exc_val.exceptions:
+                            self._insert_timeout_error(exc)
+        elif self._state is _State.ENTERED:
+            self._state = _State.EXITED
+
+        return None
+
+    def _on_timeout(self) -> None:
+        assert self._state is _State.ENTERED
+        self._task.cancel()
+        self._state = _State.EXPIRING
+        # drop the reference early
+        self._timeout_handler = None
+
+    @staticmethod
+    def _insert_timeout_error(exc_val: BaseException) -> None:
+        while exc_val.__context__ is not None:
+            if isinstance(exc_val.__context__, exceptions.CancelledError):
+                te = TimeoutError()
+                te.__context__ = te.__cause__ = exc_val.__context__
+                exc_val.__context__ = te
+                break
+            exc_val = exc_val.__context__
+
+
+def timeout(delay: Optional[float]) -> Timeout:
+    """Timeout async context manager.
+
+    Useful in cases when you want to apply timeout logic around block
+    of code or in cases when asyncio.wait_for is not suitable. For example:
+
+    >>> async with asyncio.timeout(10):  # 10 seconds timeout
+    ...     await long_running_task()
+
+
+    delay - value in seconds or None to disable timeout logic
+
+    long_running_task() is interrupted by raising asyncio.CancelledError,
+    the top-most affected timeout() context manager converts CancelledError
+    into TimeoutError.
+    """
+    loop = events.get_running_loop()
+    return Timeout(loop.time() + delay if delay is not None else None)
+
+
+def timeout_at(when: Optional[float]) -> Timeout:
+    """Schedule the timeout at absolute time.
+
+    Like timeout() but argument gives absolute time in the same clock system
+    as loop.time().
+
+    Please note: it is not POSIX time but a time with
+    undefined starting base, e.g. the time of the system power on.
+
+    >>> async with asyncio.timeout_at(loop.time() + 10):
+    ...     await long_running_task()
+
+
+    when - a deadline when timeout occurs or None to disable timeout logic
+
+    long_running_task() is interrupted by raising asyncio.CancelledError,
+    the top-most affected timeout() context manager converts CancelledError
+    into TimeoutError.
+    """
+    return Timeout(when)

Dependencies/Python/Lib/asyncio/transports.py

@@ -0,0 +1,337 @@
+"""Abstract Transport class."""
+
+__all__ = (
+    'BaseTransport', 'ReadTransport', 'WriteTransport',
+    'Transport', 'DatagramTransport', 'SubprocessTransport',
+)
+
+
+class BaseTransport:
+    """Base class for transports."""
+
+    __slots__ = ('_extra',)
+
+    def __init__(self, extra=None):
+        if extra is None:
+            extra = {}
+        self._extra = extra
+
+    def get_extra_info(self, name, default=None):
+        """Get optional transport information."""
+        return self._extra.get(name, default)
+
+    def is_closing(self):
+        """Return True if the transport is closing or closed."""
+        raise NotImplementedError
+
+    def close(self):
+        """Close the transport.
+
+        Buffered data will be flushed asynchronously.  No more data
+        will be received.  After all buffered data is flushed, the
+        protocol's connection_lost() method will (eventually) be
+        called with None as its argument.
+        """
+        raise NotImplementedError
+
+    def set_protocol(self, protocol):
+        """Set a new protocol."""
+        raise NotImplementedError
+
+    def get_protocol(self):
+        """Return the current protocol."""
+        raise NotImplementedError
+
+
+class ReadTransport(BaseTransport):
+    """Interface for read-only transports."""
+
+    __slots__ = ()
+
+    def is_reading(self):
+        """Return True if the transport is receiving."""
+        raise NotImplementedError
+
+    def pause_reading(self):
+        """Pause the receiving end.
+
+        No data will be passed to the protocol's data_received()
+        method until resume_reading() is called.
+        """
+        raise NotImplementedError
+
+    def resume_reading(self):
+        """Resume the receiving end.
+
+        Data received will once again be passed to the protocol's
+        data_received() method.
+        """
+        raise NotImplementedError
+
+
+class WriteTransport(BaseTransport):
+    """Interface for write-only transports."""
+
+    __slots__ = ()
+
+    def set_write_buffer_limits(self, high=None, low=None):
+        """Set the high- and low-water limits for write flow control.
+
+        These two values control when to call the protocol's
+        pause_writing() and resume_writing() methods.  If specified,
+        the low-water limit must be less than or equal to the
+        high-water limit.  Neither value can be negative.
+
+        The defaults are implementation-specific.  If only the
+        high-water limit is given, the low-water limit defaults to an
+        implementation-specific value less than or equal to the
+        high-water limit.  Setting high to zero forces low to zero as
+        well, and causes pause_writing() to be called whenever the
+        buffer becomes non-empty.  Setting low to zero causes
+        resume_writing() to be called only once the buffer is empty.
+        Use of zero for either limit is generally sub-optimal as it
+        reduces opportunities for doing I/O and computation
+        concurrently.
+        """
+        raise NotImplementedError
+
+    def get_write_buffer_size(self):
+        """Return the current size of the write buffer."""
+        raise NotImplementedError
+
+    def get_write_buffer_limits(self):
+        """Get the high and low watermarks for write flow control.
+        Return a tuple (low, high) where low and high are
+        positive number of bytes."""
+        raise NotImplementedError
+
+    def write(self, data):
+        """Write some data bytes to the transport.
+
+        This does not block; it buffers the data and arranges for it
+        to be sent out asynchronously.
+        """
+        raise NotImplementedError
+
+    def writelines(self, list_of_data):
+        """Write a list (or any iterable) of data bytes to the transport.
+
+        The default implementation concatenates the arguments and
+        calls write() on the result.
+        """
+        data = b''.join(list_of_data)
+        self.write(data)
+
+    def write_eof(self):
+        """Close the write end after flushing buffered data.
+
+        (This is like typing ^D into a UNIX program reading from stdin.)
+
+        Data may still be received.
+        """
+        raise NotImplementedError
+
+    def can_write_eof(self):
+        """Return True if this transport supports write_eof(), False if not."""
+        raise NotImplementedError
+
+    def abort(self):
+        """Close the transport immediately.
+
+        Buffered data will be lost.  No more data will be received.
+        The protocol's connection_lost() method will (eventually) be
+        called with None as its argument.
+        """
+        raise NotImplementedError
+
+
+class Transport(ReadTransport, WriteTransport):
+    """Interface representing a bidirectional transport.
+
+    There may be several implementations, but typically, the user does
+    not implement new transports; rather, the platform provides some
+    useful transports that are implemented using the platform's best
+    practices.
+
+    The user never instantiates a transport directly; they call a
+    utility function, passing it a protocol factory and other
+    information necessary to create the transport and protocol.  (E.g.
+    EventLoop.create_connection() or EventLoop.create_server().)
+
+    The utility function will asynchronously create a transport and a
+    protocol and hook them up by calling the protocol's
+    connection_made() method, passing it the transport.
+
+    The implementation here raises NotImplemented for every method
+    except writelines(), which calls write() in a loop.
+    """
+
+    __slots__ = ()
+
+
+class DatagramTransport(BaseTransport):
+    """Interface for datagram (UDP) transports."""
+
+    __slots__ = ()
+
+    def sendto(self, data, addr=None):
+        """Send data to the transport.
+
+        This does not block; it buffers the data and arranges for it
+        to be sent out asynchronously.
+        addr is target socket address.
+        If addr is None use target address pointed on transport creation.
+        If data is an empty bytes object a zero-length datagram will be
+        sent.
+        """
+        raise NotImplementedError
+
+    def abort(self):
+        """Close the transport immediately.
+
+        Buffered data will be lost.  No more data will be received.
+        The protocol's connection_lost() method will (eventually) be
+        called with None as its argument.
+        """
+        raise NotImplementedError
+
+
+class SubprocessTransport(BaseTransport):
+
+    __slots__ = ()
+
+    def get_pid(self):
+        """Get subprocess id."""
+        raise NotImplementedError
+
+    def get_returncode(self):
+        """Get subprocess returncode.
+
+        See also
+        http://docs.python.org/3/library/subprocess#subprocess.Popen.returncode
+        """
+        raise NotImplementedError
+
+    def get_pipe_transport(self, fd):
+        """Get transport for pipe with number fd."""
+        raise NotImplementedError
+
+    def send_signal(self, signal):
+        """Send signal to subprocess.
+
+        See also:
+        docs.python.org/3/library/subprocess#subprocess.Popen.send_signal
+        """
+        raise NotImplementedError
+
+    def terminate(self):
+        """Stop the subprocess.
+
+        Alias for close() method.
+
+        On Posix OSs the method sends SIGTERM to the subprocess.
+        On Windows the Win32 API function TerminateProcess()
+         is called to stop the subprocess.
+
+        See also:
+        http://docs.python.org/3/library/subprocess#subprocess.Popen.terminate
+        """
+        raise NotImplementedError
+
+    def kill(self):
+        """Kill the subprocess.
+
+        On Posix OSs the function sends SIGKILL to the subprocess.
+        On Windows kill() is an alias for terminate().
+
+        See also:
+        http://docs.python.org/3/library/subprocess#subprocess.Popen.kill
+        """
+        raise NotImplementedError
+
+
+class _FlowControlMixin(Transport):
+    """All the logic for (write) flow control in a mix-in base class.
+
+    The subclass must implement get_write_buffer_size().  It must call
+    _maybe_pause_protocol() whenever the write buffer size increases,
+    and _maybe_resume_protocol() whenever it decreases.  It may also
+    override set_write_buffer_limits() (e.g. to specify different
+    defaults).
+
+    The subclass constructor must call super().__init__(extra).  This
+    will call set_write_buffer_limits().
+
+    The user may call set_write_buffer_limits() and
+    get_write_buffer_size(), and their protocol's pause_writing() and
+    resume_writing() may be called.
+    """
+
+    __slots__ = ('_loop', '_protocol_paused', '_high_water', '_low_water')
+
+    def __init__(self, extra=None, loop=None):
+        super().__init__(extra)
+        assert loop is not None
+        self._loop = loop
+        self._protocol_paused = False
+        self._set_write_buffer_limits()
+
+    def _maybe_pause_protocol(self):
+        size = self.get_write_buffer_size()
+        if size <= self._high_water:
+            return
+        if not self._protocol_paused:
+            self._protocol_paused = True
+            try:
+                self._protocol.pause_writing()
+            except (SystemExit, KeyboardInterrupt):
+                raise
+            except BaseException as exc:
+                self._loop.call_exception_handler({
+                    'message': 'protocol.pause_writing() failed',
+                    'exception': exc,
+                    'transport': self,
+                    'protocol': self._protocol,
+                })
+
+    def _maybe_resume_protocol(self):
+        if (self._protocol_paused and
+                self.get_write_buffer_size() <= self._low_water):
+            self._protocol_paused = False
+            try:
+                self._protocol.resume_writing()
+            except (SystemExit, KeyboardInterrupt):
+                raise
+            except BaseException as exc:
+                self._loop.call_exception_handler({
+                    'message': 'protocol.resume_writing() failed',
+                    'exception': exc,
+                    'transport': self,
+                    'protocol': self._protocol,
+                })
+
+    def get_write_buffer_limits(self):
+        return (self._low_water, self._high_water)
+
+    def _set_write_buffer_limits(self, high=None, low=None):
+        if high is None:
+            if low is None:
+                high = 64 * 1024
+            else:
+                high = 4 * low
+        if low is None:
+            low = high // 4
+
+        if not high >= low >= 0:
+            raise ValueError(
+                f'high ({high!r}) must be >= low ({low!r}) must be >= 0')
+
+        self._high_water = high
+        self._low_water = low
+
+    def set_write_buffer_limits(self, high=None, low=None):
+        self._set_write_buffer_limits(high=high, low=low)
+        self._maybe_pause_protocol()
+
+    def get_write_buffer_size(self):
+        raise NotImplementedError

Dependencies/Python/Lib/asyncio/trsock.py

@@ -0,0 +1,98 @@
+import socket
+
+
+class TransportSocket:
+
+    """A socket-like wrapper for exposing real transport sockets.
+
+    These objects can be safely returned by APIs like
+    `transport.get_extra_info('socket')`.  All potentially disruptive
+    operations (like "socket.close()") are banned.
+    """
+
+    __slots__ = ('_sock',)
+
+    def __init__(self, sock: socket.socket):
+        self._sock = sock
+
+    @property
+    def family(self):
+        return self._sock.family
+
+    @property
+    def type(self):
+        return self._sock.type
+
+    @property
+    def proto(self):
+        return self._sock.proto
+
+    def __repr__(self):
+        s = (
+            f"<asyncio.TransportSocket fd={self.fileno()}, "
+            f"family={self.family!s}, type={self.type!s}, "
+            f"proto={self.proto}"
+        )
+
+        if self.fileno() != -1:
+            try:
+                laddr = self.getsockname()
+                if laddr:
+                    s = f"{s}, laddr={laddr}"
+            except socket.error:
+                pass
+            try:
+                raddr = self.getpeername()
+                if raddr:
+                    s = f"{s}, raddr={raddr}"
+            except socket.error:
+                pass
+
+        return f"{s}>"
+
+    def __getstate__(self):
+        raise TypeError("Cannot serialize asyncio.TransportSocket object")
+
+    def fileno(self):
+        return self._sock.fileno()
+
+    def dup(self):
+        return self._sock.dup()
+
+    def get_inheritable(self):
+        return self._sock.get_inheritable()
+
+    def shutdown(self, how):
+        # asyncio doesn't currently provide a high-level transport API
+        # to shutdown the connection.
+        self._sock.shutdown(how)
+
+    def getsockopt(self, *args, **kwargs):
+        return self._sock.getsockopt(*args, **kwargs)
+
+    def setsockopt(self, *args, **kwargs):
+        self._sock.setsockopt(*args, **kwargs)
+
+    def getpeername(self):
+        return self._sock.getpeername()
+
+    def getsockname(self):
+        return self._sock.getsockname()
+
+    def getsockbyname(self):
+        return self._sock.getsockbyname()
+
+    def settimeout(self, value):
+        if value == 0:
+            return
+        raise ValueError(
+            'settimeout(): only 0 timeout is allowed on transport sockets')
+
+    def gettimeout(self):
+        return 0
+
+    def setblocking(self, flag):
+        if not flag:
+            return
+        raise ValueError(
+            'setblocking(): transport sockets cannot be blocking')

Dependencies/Python/Lib/asyncio/windows_events.py

@@ -0,0 +1,903 @@
+"""Selector and proactor event loops for Windows."""
+
+import sys
+
+if sys.platform != 'win32':  # pragma: no cover
+    raise ImportError('win32 only')
+
+import _overlapped
+import _winapi
+import errno
+from functools import partial
+import math
+import msvcrt
+import socket
+import struct
+import time
+import weakref
+
+from . import events
+from . import base_subprocess
+from . import futures
+from . import exceptions
+from . import proactor_events
+from . import selector_events
+from . import tasks
+from . import windows_utils
+from .log import logger
+
+
+__all__ = (
+    'SelectorEventLoop', 'ProactorEventLoop', 'IocpProactor',
+    'DefaultEventLoopPolicy', 'WindowsSelectorEventLoopPolicy',
+    'WindowsProactorEventLoopPolicy', 'EventLoop',
+)
+
+
+NULL = _winapi.NULL
+INFINITE = _winapi.INFINITE
+ERROR_CONNECTION_REFUSED = 1225
+ERROR_CONNECTION_ABORTED = 1236
+
+# Initial delay in seconds for connect_pipe() before retrying to connect
+CONNECT_PIPE_INIT_DELAY = 0.001
+
+# Maximum delay in seconds for connect_pipe() before retrying to connect
+CONNECT_PIPE_MAX_DELAY = 0.100
+
+
+class _OverlappedFuture(futures.Future):
+    """Subclass of Future which represents an overlapped operation.
+
+    Cancelling it will immediately cancel the overlapped operation.
+    """
+
+    def __init__(self, ov, *, loop=None):
+        super().__init__(loop=loop)
+        if self._source_traceback:
+            del self._source_traceback[-1]
+        self._ov = ov
+
+    def _repr_info(self):
+        info = super()._repr_info()
+        if self._ov is not None:
+            state = 'pending' if self._ov.pending else 'completed'
+            info.insert(1, f'overlapped=<{state}, {self._ov.address:#x}>')
+        return info
+
+    def _cancel_overlapped(self):
+        if self._ov is None:
+            return
+        try:
+            self._ov.cancel()
+        except OSError as exc:
+            context = {
+                'message': 'Cancelling an overlapped future failed',
+                'exception': exc,
+                'future': self,
+            }
+            if self._source_traceback:
+                context['source_traceback'] = self._source_traceback
+            self._loop.call_exception_handler(context)
+        self._ov = None
+
+    def cancel(self, msg=None):
+        self._cancel_overlapped()
+        return super().cancel(msg=msg)
+
+    def set_exception(self, exception):
+        super().set_exception(exception)
+        self._cancel_overlapped()
+
+    def set_result(self, result):
+        super().set_result(result)
+        self._ov = None
+
+
+class _BaseWaitHandleFuture(futures.Future):
+    """Subclass of Future which represents a wait handle."""
+
+    def __init__(self, ov, handle, wait_handle, *, loop=None):
+        super().__init__(loop=loop)
+        if self._source_traceback:
+            del self._source_traceback[-1]
+        # Keep a reference to the Overlapped object to keep it alive until the
+        # wait is unregistered
+        self._ov = ov
+        self._handle = handle
+        self._wait_handle = wait_handle
+
+        # Should we call UnregisterWaitEx() if the wait completes
+        # or is cancelled?
+        self._registered = True
+
+    def _poll(self):
+        # non-blocking wait: use a timeout of 0 millisecond
+        return (_winapi.WaitForSingleObject(self._handle, 0) ==
+                _winapi.WAIT_OBJECT_0)
+
+    def _repr_info(self):
+        info = super()._repr_info()
+        info.append(f'handle={self._handle:#x}')
+        if self._handle is not None:
+            state = 'signaled' if self._poll() else 'waiting'
+            info.append(state)
+        if self._wait_handle is not None:
+            info.append(f'wait_handle={self._wait_handle:#x}')
+        return info
+
+    def _unregister_wait_cb(self, fut):
+        # The wait was unregistered: it's not safe to destroy the Overlapped
+        # object
+        self._ov = None
+
+    def _unregister_wait(self):
+        if not self._registered:
+            return
+        self._registered = False
+
+        wait_handle = self._wait_handle
+        self._wait_handle = None
+        try:
+            _overlapped.UnregisterWait(wait_handle)
+        except OSError as exc:
+            if exc.winerror != _overlapped.ERROR_IO_PENDING:
+                context = {
+                    'message': 'Failed to unregister the wait handle',
+                    'exception': exc,
+                    'future': self,
+                }
+                if self._source_traceback:
+                    context['source_traceback'] = self._source_traceback
+                self._loop.call_exception_handler(context)
+                return
+            # ERROR_IO_PENDING means that the unregister is pending
+
+        self._unregister_wait_cb(None)
+
+    def cancel(self, msg=None):
+        self._unregister_wait()
+        return super().cancel(msg=msg)
+
+    def set_exception(self, exception):
+        self._unregister_wait()
+        super().set_exception(exception)
+
+    def set_result(self, result):
+        self._unregister_wait()
+        super().set_result(result)
+
+
+class _WaitCancelFuture(_BaseWaitHandleFuture):
+    """Subclass of Future which represents a wait for the cancellation of a
+    _WaitHandleFuture using an event.
+    """
+
+    def __init__(self, ov, event, wait_handle, *, loop=None):
+        super().__init__(ov, event, wait_handle, loop=loop)
+
+        self._done_callback = None
+
+    def cancel(self):
+        raise RuntimeError("_WaitCancelFuture must not be cancelled")
+
+    def set_result(self, result):
+        super().set_result(result)
+        if self._done_callback is not None:
+            self._done_callback(self)
+
+    def set_exception(self, exception):
+        super().set_exception(exception)
+        if self._done_callback is not None:
+            self._done_callback(self)
+
+
+class _WaitHandleFuture(_BaseWaitHandleFuture):
+    def __init__(self, ov, handle, wait_handle, proactor, *, loop=None):
+        super().__init__(ov, handle, wait_handle, loop=loop)
+        self._proactor = proactor
+        self._unregister_proactor = True
+        self._event = _overlapped.CreateEvent(None, True, False, None)
+        self._event_fut = None
+
+    def _unregister_wait_cb(self, fut):
+        if self._event is not None:
+            _winapi.CloseHandle(self._event)
+            self._event = None
+            self._event_fut = None
+
+        # If the wait was cancelled, the wait may never be signalled, so
+        # it's required to unregister it. Otherwise, IocpProactor.close() will
+        # wait forever for an event which will never come.
+        #
+        # If the IocpProactor already received the event, it's safe to call
+        # _unregister() because we kept a reference to the Overlapped object
+        # which is used as a unique key.
+        self._proactor._unregister(self._ov)
+        self._proactor = None
+
+        super()._unregister_wait_cb(fut)
+
+    def _unregister_wait(self):
+        if not self._registered:
+            return
+        self._registered = False
+
+        wait_handle = self._wait_handle
+        self._wait_handle = None
+        try:
+            _overlapped.UnregisterWaitEx(wait_handle, self._event)
+        except OSError as exc:
+            if exc.winerror != _overlapped.ERROR_IO_PENDING:
+                context = {
+                    'message': 'Failed to unregister the wait handle',
+                    'exception': exc,
+                    'future': self,
+                }
+                if self._source_traceback:
+                    context['source_traceback'] = self._source_traceback
+                self._loop.call_exception_handler(context)
+                return
+            # ERROR_IO_PENDING is not an error, the wait was unregistered
+
+        self._event_fut = self._proactor._wait_cancel(self._event,
+                                                      self._unregister_wait_cb)
+
+
+class PipeServer(object):
+    """Class representing a pipe server.
+
+    This is much like a bound, listening socket.
+    """
+    def __init__(self, address):
+        self._address = address
+        self._free_instances = weakref.WeakSet()
+        # initialize the pipe attribute before calling _server_pipe_handle()
+        # because this function can raise an exception and the destructor calls
+        # the close() method
+        self._pipe = None
+        self._accept_pipe_future = None
+        self._pipe = self._server_pipe_handle(True)
+
+    def _get_unconnected_pipe(self):
+        # Create new instance and return previous one.  This ensures
+        # that (until the server is closed) there is always at least
+        # one pipe handle for address.  Therefore if a client attempt
+        # to connect it will not fail with FileNotFoundError.
+        tmp, self._pipe = self._pipe, self._server_pipe_handle(False)
+        return tmp
+
+    def _server_pipe_handle(self, first):
+        # Return a wrapper for a new pipe handle.
+        if self.closed():
+            return None
+        flags = _winapi.PIPE_ACCESS_DUPLEX | _winapi.FILE_FLAG_OVERLAPPED
+        if first:
+            flags |= _winapi.FILE_FLAG_FIRST_PIPE_INSTANCE
+        h = _winapi.CreateNamedPipe(
+            self._address, flags,
+            _winapi.PIPE_TYPE_MESSAGE | _winapi.PIPE_READMODE_MESSAGE |
+            _winapi.PIPE_WAIT,
+            _winapi.PIPE_UNLIMITED_INSTANCES,
+            windows_utils.BUFSIZE, windows_utils.BUFSIZE,
+            _winapi.NMPWAIT_WAIT_FOREVER, _winapi.NULL)
+        pipe = windows_utils.PipeHandle(h)
+        self._free_instances.add(pipe)
+        return pipe
+
+    def closed(self):
+        return (self._address is None)
+
+    def close(self):
+        if self._accept_pipe_future is not None:
+            self._accept_pipe_future.cancel()
+            self._accept_pipe_future = None
+        # Close all instances which have not been connected to by a client.
+        if self._address is not None:
+            for pipe in self._free_instances:
+                pipe.close()
+            self._pipe = None
+            self._address = None
+            self._free_instances.clear()
+
+    __del__ = close
+
+
+class _WindowsSelectorEventLoop(selector_events.BaseSelectorEventLoop):
+    """Windows version of selector event loop."""
+
+
+class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
+    """Windows version of proactor event loop using IOCP."""
+
+    def __init__(self, proactor=None):
+        if proactor is None:
+            proactor = IocpProactor()
+        super().__init__(proactor)
+
+    def _run_forever_setup(self):
+        assert self._self_reading_future is None
+        self.call_soon(self._loop_self_reading)
+        super()._run_forever_setup()
+
+    def _run_forever_cleanup(self):
+        super()._run_forever_cleanup()
+        if self._self_reading_future is not None:
+            ov = self._self_reading_future._ov
+            self._self_reading_future.cancel()
+            # self_reading_future always uses IOCP, so even though it's
+            # been cancelled, we need to make sure that the IOCP message
+            # is received so that the kernel is not holding on to the
+            # memory, possibly causing memory corruption later. Only
+            # unregister it if IO is complete in all respects. Otherwise
+            # we need another _poll() later to complete the IO.
+            if ov is not None and not ov.pending:
+                self._proactor._unregister(ov)
+            self._self_reading_future = None
+
+    async def create_pipe_connection(self, protocol_factory, address):
+        f = self._proactor.connect_pipe(address)
+        pipe = await f
+        protocol = protocol_factory()
+        trans = self._make_duplex_pipe_transport(pipe, protocol,
+                                                 extra={'addr': address})
+        return trans, protocol
+
+    async def start_serving_pipe(self, protocol_factory, address):
+        server = PipeServer(address)
+
+        def loop_accept_pipe(f=None):
+            pipe = None
+            try:
+                if f:
+                    pipe = f.result()
+                    server._free_instances.discard(pipe)
+
+                    if server.closed():
+                        # A client connected before the server was closed:
+                        # drop the client (close the pipe) and exit
+                        pipe.close()
+                        return
+
+                    protocol = protocol_factory()
+                    self._make_duplex_pipe_transport(
+                        pipe, protocol, extra={'addr': address})
+
+                pipe = server._get_unconnected_pipe()
+                if pipe is None:
+                    return
+
+                f = self._proactor.accept_pipe(pipe)
+            except BrokenPipeError:
+                if pipe and pipe.fileno() != -1:
+                    pipe.close()
+                self.call_soon(loop_accept_pipe)
+            except OSError as exc:
+                if pipe and pipe.fileno() != -1:
+                    self.call_exception_handler({
+                        'message': 'Pipe accept failed',
+                        'exception': exc,
+                        'pipe': pipe,
+                    })
+                    pipe.close()
+                elif self._debug:
+                    logger.warning("Accept pipe failed on pipe %r",
+                                   pipe, exc_info=True)
+                self.call_soon(loop_accept_pipe)
+            except exceptions.CancelledError:
+                if pipe:
+                    pipe.close()
+            else:
+                server._accept_pipe_future = f
+                f.add_done_callback(loop_accept_pipe)
+
+        self.call_soon(loop_accept_pipe)
+        return [server]
+
+    async def _make_subprocess_transport(self, protocol, args, shell,
+                                         stdin, stdout, stderr, bufsize,
+                                         extra=None, **kwargs):
+        waiter = self.create_future()
+        transp = _WindowsSubprocessTransport(self, protocol, args, shell,
+                                             stdin, stdout, stderr, bufsize,
+                                             waiter=waiter, extra=extra,
+                                             **kwargs)
+        try:
+            await waiter
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException:
+            transp.close()
+            await transp._wait()
+            raise
+
+        return transp
+
+
+class IocpProactor:
+    """Proactor implementation using IOCP."""
+
+    def __init__(self, concurrency=INFINITE):
+        self._loop = None
+        self._results = []
+        self._iocp = _overlapped.CreateIoCompletionPort(
+            _overlapped.INVALID_HANDLE_VALUE, NULL, 0, concurrency)
+        self._cache = {}
+        self._registered = weakref.WeakSet()
+        self._unregistered = []
+        self._stopped_serving = weakref.WeakSet()
+
+    def _check_closed(self):
+        if self._iocp is None:
+            raise RuntimeError('IocpProactor is closed')
+
+    def __repr__(self):
+        info = ['overlapped#=%s' % len(self._cache),
+                'result#=%s' % len(self._results)]
+        if self._iocp is None:
+            info.append('closed')
+        return '<%s %s>' % (self.__class__.__name__, " ".join(info))
+
+    def set_loop(self, loop):
+        self._loop = loop
+
+    def select(self, timeout=None):
+        if not self._results:
+            self._poll(timeout)
+        tmp = self._results
+        self._results = []
+        try:
+            return tmp
+        finally:
+            # Needed to break cycles when an exception occurs.
+            tmp = None
+
+    def _result(self, value):
+        fut = self._loop.create_future()
+        fut.set_result(value)
+        return fut
+
+    @staticmethod
+    def finish_socket_func(trans, key, ov):
+        try:
+            return ov.getresult()
+        except OSError as exc:
+            if exc.winerror in (_overlapped.ERROR_NETNAME_DELETED,
+                                _overlapped.ERROR_OPERATION_ABORTED):
+                raise ConnectionResetError(*exc.args)
+            else:
+                raise
+
+    @classmethod
+    def _finish_recvfrom(cls, trans, key, ov, *, empty_result):
+        try:
+            return cls.finish_socket_func(trans, key, ov)
+        except OSError as exc:
+            # WSARecvFrom will report ERROR_PORT_UNREACHABLE when the same
+            # socket is used to send to an address that is not listening.
+            if exc.winerror == _overlapped.ERROR_PORT_UNREACHABLE:
+                return empty_result, None
+            else:
+                raise
+
+    def recv(self, conn, nbytes, flags=0):
+        self._register_with_iocp(conn)
+        ov = _overlapped.Overlapped(NULL)
+        try:
+            if isinstance(conn, socket.socket):
+                ov.WSARecv(conn.fileno(), nbytes, flags)
+            else:
+                ov.ReadFile(conn.fileno(), nbytes)
+        except BrokenPipeError:
+            return self._result(b'')
+
+        return self._register(ov, conn, self.finish_socket_func)
+
+    def recv_into(self, conn, buf, flags=0):
+        self._register_with_iocp(conn)
+        ov = _overlapped.Overlapped(NULL)
+        try:
+            if isinstance(conn, socket.socket):
+                ov.WSARecvInto(conn.fileno(), buf, flags)
+            else:
+                ov.ReadFileInto(conn.fileno(), buf)
+        except BrokenPipeError:
+            return self._result(0)
+
+        return self._register(ov, conn, self.finish_socket_func)
+
+    def recvfrom(self, conn, nbytes, flags=0):
+        self._register_with_iocp(conn)
+        ov = _overlapped.Overlapped(NULL)
+        try:
+            ov.WSARecvFrom(conn.fileno(), nbytes, flags)
+        except BrokenPipeError:
+            return self._result((b'', None))
+
+        return self._register(ov, conn, partial(self._finish_recvfrom,
+                                                empty_result=b''))
+
+    def recvfrom_into(self, conn, buf, flags=0):
+        self._register_with_iocp(conn)
+        ov = _overlapped.Overlapped(NULL)
+        try:
+            ov.WSARecvFromInto(conn.fileno(), buf, flags)
+        except BrokenPipeError:
+            return self._result((0, None))
+
+        return self._register(ov, conn, partial(self._finish_recvfrom,
+                                                empty_result=0))
+
+    def sendto(self, conn, buf, flags=0, addr=None):
+        self._register_with_iocp(conn)
+        ov = _overlapped.Overlapped(NULL)
+
+        ov.WSASendTo(conn.fileno(), buf, flags, addr)
+
+        return self._register(ov, conn, self.finish_socket_func)
+
+    def send(self, conn, buf, flags=0):
+        self._register_with_iocp(conn)
+        ov = _overlapped.Overlapped(NULL)
+        if isinstance(conn, socket.socket):
+            ov.WSASend(conn.fileno(), buf, flags)
+        else:
+            ov.WriteFile(conn.fileno(), buf)
+
+        return self._register(ov, conn, self.finish_socket_func)
+
+    def accept(self, listener):
+        self._register_with_iocp(listener)
+        conn = self._get_accept_socket(listener.family)
+        ov = _overlapped.Overlapped(NULL)
+        ov.AcceptEx(listener.fileno(), conn.fileno())
+
+        def finish_accept(trans, key, ov):
+            ov.getresult()
+            # Use SO_UPDATE_ACCEPT_CONTEXT so getsockname() etc work.
+            buf = struct.pack('@P', listener.fileno())
+            conn.setsockopt(socket.SOL_SOCKET,
+                            _overlapped.SO_UPDATE_ACCEPT_CONTEXT, buf)
+            conn.settimeout(listener.gettimeout())
+            return conn, conn.getpeername()
+
+        async def accept_coro(future, conn):
+            # Coroutine closing the accept socket if the future is cancelled
+            try:
+                await future
+            except exceptions.CancelledError:
+                conn.close()
+                raise
+
+        future = self._register(ov, listener, finish_accept)
+        coro = accept_coro(future, conn)
+        tasks.ensure_future(coro, loop=self._loop)
+        return future
+
+    def connect(self, conn, address):
+        if conn.type == socket.SOCK_DGRAM:
+            # WSAConnect will complete immediately for UDP sockets so we don't
+            # need to register any IOCP operation
+            _overlapped.WSAConnect(conn.fileno(), address)
+            fut = self._loop.create_future()
+            fut.set_result(None)
+            return fut
+
+        self._register_with_iocp(conn)
+        # The socket needs to be locally bound before we call ConnectEx().
+        try:
+            _overlapped.BindLocal(conn.fileno(), conn.family)
+        except OSError as e:
+            if e.winerror != errno.WSAEINVAL:
+                raise
+            # Probably already locally bound; check using getsockname().
+            if conn.getsockname()[1] == 0:
+                raise
+        ov = _overlapped.Overlapped(NULL)
+        ov.ConnectEx(conn.fileno(), address)
+
+        def finish_connect(trans, key, ov):
+            ov.getresult()
+            # Use SO_UPDATE_CONNECT_CONTEXT so getsockname() etc work.
+            conn.setsockopt(socket.SOL_SOCKET,
+                            _overlapped.SO_UPDATE_CONNECT_CONTEXT, 0)
+            return conn
+
+        return self._register(ov, conn, finish_connect)
+
+    def sendfile(self, sock, file, offset, count):
+        self._register_with_iocp(sock)
+        ov = _overlapped.Overlapped(NULL)
+        offset_low = offset & 0xffff_ffff
+        offset_high = (offset >> 32) & 0xffff_ffff
+        ov.TransmitFile(sock.fileno(),
+                        msvcrt.get_osfhandle(file.fileno()),
+                        offset_low, offset_high,
+                        count, 0, 0)
+
+        return self._register(ov, sock, self.finish_socket_func)
+
+    def accept_pipe(self, pipe):
+        self._register_with_iocp(pipe)
+        ov = _overlapped.Overlapped(NULL)
+        connected = ov.ConnectNamedPipe(pipe.fileno())
+
+        if connected:
+            # ConnectNamePipe() failed with ERROR_PIPE_CONNECTED which means
+            # that the pipe is connected. There is no need to wait for the
+            # completion of the connection.
+            return self._result(pipe)
+
+        def finish_accept_pipe(trans, key, ov):
+            ov.getresult()
+            return pipe
+
+        return self._register(ov, pipe, finish_accept_pipe)
+
+    async def connect_pipe(self, address):
+        delay = CONNECT_PIPE_INIT_DELAY
+        while True:
+            # Unfortunately there is no way to do an overlapped connect to
+            # a pipe.  Call CreateFile() in a loop until it doesn't fail with
+            # ERROR_PIPE_BUSY.
+            try:
+                handle = _overlapped.ConnectPipe(address)
+                break
+            except OSError as exc:
+                if exc.winerror != _overlapped.ERROR_PIPE_BUSY:
+                    raise
+
+            # ConnectPipe() failed with ERROR_PIPE_BUSY: retry later
+            delay = min(delay * 2, CONNECT_PIPE_MAX_DELAY)
+            await tasks.sleep(delay)
+
+        return windows_utils.PipeHandle(handle)
+
+    def wait_for_handle(self, handle, timeout=None):
+        """Wait for a handle.
+
+        Return a Future object. The result of the future is True if the wait
+        completed, or False if the wait did not complete (on timeout).
+        """
+        return self._wait_for_handle(handle, timeout, False)
+
+    def _wait_cancel(self, event, done_callback):
+        fut = self._wait_for_handle(event, None, True)
+        # add_done_callback() cannot be used because the wait may only complete
+        # in IocpProactor.close(), while the event loop is not running.
+        fut._done_callback = done_callback
+        return fut
+
+    def _wait_for_handle(self, handle, timeout, _is_cancel):
+        self._check_closed()
+
+        if timeout is None:
+            ms = _winapi.INFINITE
+        else:
+            # RegisterWaitForSingleObject() has a resolution of 1 millisecond,
+            # round away from zero to wait *at least* timeout seconds.
+            ms = math.ceil(timeout * 1e3)
+
+        # We only create ov so we can use ov.address as a key for the cache.
+        ov = _overlapped.Overlapped(NULL)
+        wait_handle = _overlapped.RegisterWaitWithQueue(
+            handle, self._iocp, ov.address, ms)
+        if _is_cancel:
+            f = _WaitCancelFuture(ov, handle, wait_handle, loop=self._loop)
+        else:
+            f = _WaitHandleFuture(ov, handle, wait_handle, self,
+                                  loop=self._loop)
+        if f._source_traceback:
+            del f._source_traceback[-1]
+
+        def finish_wait_for_handle(trans, key, ov):
+            # Note that this second wait means that we should only use
+            # this with handles types where a successful wait has no
+            # effect.  So events or processes are all right, but locks
+            # or semaphores are not.  Also note if the handle is
+            # signalled and then quickly reset, then we may return
+            # False even though we have not timed out.
+            return f._poll()
+
+        self._cache[ov.address] = (f, ov, 0, finish_wait_for_handle)
+        return f
+
+    def _register_with_iocp(self, obj):
+        # To get notifications of finished ops on this objects sent to the
+        # completion port, were must register the handle.
+        if obj not in self._registered:
+            self._registered.add(obj)
+            _overlapped.CreateIoCompletionPort(obj.fileno(), self._iocp, 0, 0)
+            # XXX We could also use SetFileCompletionNotificationModes()
+            # to avoid sending notifications to completion port of ops
+            # that succeed immediately.
+
+    def _register(self, ov, obj, callback):
+        self._check_closed()
+
+        # Return a future which will be set with the result of the
+        # operation when it completes.  The future's value is actually
+        # the value returned by callback().
+        f = _OverlappedFuture(ov, loop=self._loop)
+        if f._source_traceback:
+            del f._source_traceback[-1]
+        if not ov.pending:
+            # The operation has completed, so no need to postpone the
+            # work.  We cannot take this short cut if we need the
+            # NumberOfBytes, CompletionKey values returned by
+            # PostQueuedCompletionStatus().
+            try:
+                value = callback(None, None, ov)
+            except OSError as e:
+                f.set_exception(e)
+            else:
+                f.set_result(value)
+            # Even if GetOverlappedResult() was called, we have to wait for the
+            # notification of the completion in GetQueuedCompletionStatus().
+            # Register the overlapped operation to keep a reference to the
+            # OVERLAPPED object, otherwise the memory is freed and Windows may
+            # read uninitialized memory.
+
+        # Register the overlapped operation for later.  Note that
+        # we only store obj to prevent it from being garbage
+        # collected too early.
+        self._cache[ov.address] = (f, ov, obj, callback)
+        return f
+
+    def _unregister(self, ov):
+        """Unregister an overlapped object.
+
+        Call this method when its future has been cancelled. The event can
+        already be signalled (pending in the proactor event queue). It is also
+        safe if the event is never signalled (because it was cancelled).
+        """
+        self._check_closed()
+        self._unregistered.append(ov)
+
+    def _get_accept_socket(self, family):
+        s = socket.socket(family)
+        s.settimeout(0)
+        return s
+
+    def _poll(self, timeout=None):
+        if timeout is None:
+            ms = INFINITE
+        elif timeout < 0:
+            raise ValueError("negative timeout")
+        else:
+            # GetQueuedCompletionStatus() has a resolution of 1 millisecond,
+            # round away from zero to wait *at least* timeout seconds.
+            ms = math.ceil(timeout * 1e3)
+            if ms >= INFINITE:
+                raise ValueError("timeout too big")
+
+        while True:
+            status = _overlapped.GetQueuedCompletionStatus(self._iocp, ms)
+            if status is None:
+                break
+            ms = 0
+
+            err, transferred, key, address = status
+            try:
+                f, ov, obj, callback = self._cache.pop(address)
+            except KeyError:
+                if self._loop.get_debug():
+                    self._loop.call_exception_handler({
+                        'message': ('GetQueuedCompletionStatus() returned an '
+                                    'unexpected event'),
+                        'status': ('err=%s transferred=%s key=%#x address=%#x'
+                                   % (err, transferred, key, address)),
+                    })
+
+                # key is either zero, or it is used to return a pipe
+                # handle which should be closed to avoid a leak.
+                if key not in (0, _overlapped.INVALID_HANDLE_VALUE):
+                    _winapi.CloseHandle(key)
+                continue
+
+            if obj in self._stopped_serving:
+                f.cancel()
+            # Don't call the callback if _register() already read the result or
+            # if the overlapped has been cancelled
+            elif not f.done():
+                try:
+                    value = callback(transferred, key, ov)
+                except OSError as e:
+                    f.set_exception(e)
+                    self._results.append(f)
+                else:
+                    f.set_result(value)
+                    self._results.append(f)
+                finally:
+                    f = None
+
+        # Remove unregistered futures
+        for ov in self._unregistered:
+            self._cache.pop(ov.address, None)
+        self._unregistered.clear()
+
+    def _stop_serving(self, obj):
+        # obj is a socket or pipe handle.  It will be closed in
+        # BaseProactorEventLoop._stop_serving() which will make any
+        # pending operations fail quickly.
+        self._stopped_serving.add(obj)
+
+    def close(self):
+        if self._iocp is None:
+            # already closed
+            return
+
+        # Cancel remaining registered operations.
+        for fut, ov, obj, callback in list(self._cache.values()):
+            if fut.cancelled():
+                # Nothing to do with cancelled futures
+                pass
+            elif isinstance(fut, _WaitCancelFuture):
+                # _WaitCancelFuture must not be cancelled
+                pass
+            else:
+                try:
+                    fut.cancel()
+                except OSError as exc:
+                    if self._loop is not None:
+                        context = {
+                            'message': 'Cancelling a future failed',
+                            'exception': exc,
+                            'future': fut,
+                        }
+                        if fut._source_traceback:
+                            context['source_traceback'] = fut._source_traceback
+                        self._loop.call_exception_handler(context)
+
+        # Wait until all cancelled overlapped complete: don't exit with running
+        # overlapped to prevent a crash. Display progress every second if the
+        # loop is still running.
+        msg_update = 1.0
+        start_time = time.monotonic()
+        next_msg = start_time + msg_update
+        while self._cache:
+            if next_msg <= time.monotonic():
+                logger.debug('%r is running after closing for %.1f seconds',
+                             self, time.monotonic() - start_time)
+                next_msg = time.monotonic() + msg_update
+
+            # handle a few events, or timeout
+            self._poll(msg_update)
+
+        self._results = []
+
+        _winapi.CloseHandle(self._iocp)
+        self._iocp = None
+
+    def __del__(self):
+        self.close()
+
+
+class _WindowsSubprocessTransport(base_subprocess.BaseSubprocessTransport):
+
+    def _start(self, args, shell, stdin, stdout, stderr, bufsize, **kwargs):
+        self._proc = windows_utils.Popen(
+            args, shell=shell, stdin=stdin, stdout=stdout, stderr=stderr,
+            bufsize=bufsize, **kwargs)
+
+        def callback(f):
+            returncode = self._proc.poll()
+            self._process_exited(returncode)
+
+        f = self._loop._proactor.wait_for_handle(int(self._proc._handle))
+        f.add_done_callback(callback)
+
+
+SelectorEventLoop = _WindowsSelectorEventLoop
+
+
+class WindowsSelectorEventLoopPolicy(events.BaseDefaultEventLoopPolicy):
+    _loop_factory = SelectorEventLoop
+
+
+class WindowsProactorEventLoopPolicy(events.BaseDefaultEventLoopPolicy):
+    _loop_factory = ProactorEventLoop
+
+
+DefaultEventLoopPolicy = WindowsProactorEventLoopPolicy
+EventLoop = ProactorEventLoop

Dependencies/Python/Lib/asyncio/windows_utils.py

@@ -0,0 +1,173 @@
+"""Various Windows specific bits and pieces."""
+
+import sys
+
+if sys.platform != 'win32':  # pragma: no cover
+    raise ImportError('win32 only')
+
+import _winapi
+import itertools
+import msvcrt
+import os
+import subprocess
+import tempfile
+import warnings
+
+
+__all__ = 'pipe', 'Popen', 'PIPE', 'PipeHandle'
+
+
+# Constants/globals
+
+
+BUFSIZE = 8192
+PIPE = subprocess.PIPE
+STDOUT = subprocess.STDOUT
+_mmap_counter = itertools.count()
+
+
+# Replacement for os.pipe() using handles instead of fds
+
+
+def pipe(*, duplex=False, overlapped=(True, True), bufsize=BUFSIZE):
+    """Like os.pipe() but with overlapped support and using handles not fds."""
+    address = tempfile.mktemp(
+        prefix=r'\\.\pipe\python-pipe-{:d}-{:d}-'.format(
+            os.getpid(), next(_mmap_counter)))
+
+    if duplex:
+        openmode = _winapi.PIPE_ACCESS_DUPLEX
+        access = _winapi.GENERIC_READ | _winapi.GENERIC_WRITE
+        obsize, ibsize = bufsize, bufsize
+    else:
+        openmode = _winapi.PIPE_ACCESS_INBOUND
+        access = _winapi.GENERIC_WRITE
+        obsize, ibsize = 0, bufsize
+
+    openmode |= _winapi.FILE_FLAG_FIRST_PIPE_INSTANCE
+
+    if overlapped[0]:
+        openmode |= _winapi.FILE_FLAG_OVERLAPPED
+
+    if overlapped[1]:
+        flags_and_attribs = _winapi.FILE_FLAG_OVERLAPPED
+    else:
+        flags_and_attribs = 0
+
+    h1 = h2 = None
+    try:
+        h1 = _winapi.CreateNamedPipe(
+            address, openmode, _winapi.PIPE_WAIT,
+            1, obsize, ibsize, _winapi.NMPWAIT_WAIT_FOREVER, _winapi.NULL)
+
+        h2 = _winapi.CreateFile(
+            address, access, 0, _winapi.NULL, _winapi.OPEN_EXISTING,
+            flags_and_attribs, _winapi.NULL)
+
+        ov = _winapi.ConnectNamedPipe(h1, overlapped=True)
+        ov.GetOverlappedResult(True)
+        return h1, h2
+    except:
+        if h1 is not None:
+            _winapi.CloseHandle(h1)
+        if h2 is not None:
+            _winapi.CloseHandle(h2)
+        raise
+
+
+# Wrapper for a pipe handle
+
+
+class PipeHandle:
+    """Wrapper for an overlapped pipe handle which is vaguely file-object like.
+
+    The IOCP event loop can use these instead of socket objects.
+    """
+    def __init__(self, handle):
+        self._handle = handle
+
+    def __repr__(self):
+        if self._handle is not None:
+            handle = f'handle={self._handle!r}'
+        else:
+            handle = 'closed'
+        return f'<{self.__class__.__name__} {handle}>'
+
+    @property
+    def handle(self):
+        return self._handle
+
+    def fileno(self):
+        if self._handle is None:
+            raise ValueError("I/O operation on closed pipe")
+        return self._handle
+
+    def close(self, *, CloseHandle=_winapi.CloseHandle):
+        if self._handle is not None:
+            CloseHandle(self._handle)
+            self._handle = None
+
+    def __del__(self, _warn=warnings.warn):
+        if self._handle is not None:
+            _warn(f"unclosed {self!r}", ResourceWarning, source=self)
+            self.close()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, t, v, tb):
+        self.close()
+
+
+# Replacement for subprocess.Popen using overlapped pipe handles
+
+
+class Popen(subprocess.Popen):
+    """Replacement for subprocess.Popen using overlapped pipe handles.
+
+    The stdin, stdout, stderr are None or instances of PipeHandle.
+    """
+    def __init__(self, args, stdin=None, stdout=None, stderr=None, **kwds):
+        assert not kwds.get('universal_newlines')
+        assert kwds.get('bufsize', 0) == 0
+        stdin_rfd = stdout_wfd = stderr_wfd = None
+        stdin_wh = stdout_rh = stderr_rh = None
+        if stdin == PIPE:
+            stdin_rh, stdin_wh = pipe(overlapped=(False, True), duplex=True)
+            stdin_rfd = msvcrt.open_osfhandle(stdin_rh, os.O_RDONLY)
+        else:
+            stdin_rfd = stdin
+        if stdout == PIPE:
+            stdout_rh, stdout_wh = pipe(overlapped=(True, False))
+            stdout_wfd = msvcrt.open_osfhandle(stdout_wh, 0)
+        else:
+            stdout_wfd = stdout
+        if stderr == PIPE:
+            stderr_rh, stderr_wh = pipe(overlapped=(True, False))
+            stderr_wfd = msvcrt.open_osfhandle(stderr_wh, 0)
+        elif stderr == STDOUT:
+            stderr_wfd = stdout_wfd
+        else:
+            stderr_wfd = stderr
+        try:
+            super().__init__(args, stdin=stdin_rfd, stdout=stdout_wfd,
+                             stderr=stderr_wfd, **kwds)
+        except:
+            for h in (stdin_wh, stdout_rh, stderr_rh):
+                if h is not None:
+                    _winapi.CloseHandle(h)
+            raise
+        else:
+            if stdin_wh is not None:
+                self.stdin = PipeHandle(stdin_wh)
+            if stdout_rh is not None:
+                self.stdout = PipeHandle(stdout_rh)
+            if stderr_rh is not None:
+                self.stderr = PipeHandle(stderr_rh)
+        finally:
+            if stdin == PIPE:
+                os.close(stdin_rfd)
+            if stdout == PIPE:
+                os.close(stdout_wfd)
+            if stderr == PIPE:
+                os.close(stderr_wfd)