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/usr/lib/python3/dist-packages/twisted/internet/

/usr/lib/python3/dist-packages/twisted/internet

Name	Size	Mode	Actions
iocpreactor/	-	0755	rm
test/	-	0755	rm
__pycache__/	-	0755	rm
abstract.py	19295	0644	edit dl rm
address.py	5244	0644	edit dl rm
asyncioreactor.py	11131	0644	edit dl rm
base.py	47392	0644	edit dl rm
cfreactor.py	17499	0644	edit dl rm
default.py	1893	0644	edit dl rm
defer.py	85654	0644	edit dl rm
endpoints.py	77440	0644	edit dl rm
epollreactor.py	8941	0644	edit dl rm
error.py	13482	0644	edit dl rm
fdesc.py	3237	0644	edit dl rm
gireactor.py	4620	0644	edit dl rm
glib2reactor.py	1115	0644	edit dl rm
gtk2reactor.py	3640	0644	edit dl rm
gtk3reactor.py	1527	0644	edit dl rm
inotify.py	14396	0644	edit dl rm
interfaces.py	98048	0644	edit dl rm
kqreactor.py	10818	0644	edit dl rm
main.py	1006	0644	edit dl rm
pollreactor.py	5974	0644	edit dl rm
posixbase.py	27604	0644	edit dl rm
process.py	38516	0644	edit dl rm
protocol.py	27391	0644	edit dl rm
pyuisupport.py	843	0644	edit dl rm
reactor.py	1816	0644	edit dl rm
selectreactor.py	6102	0644	edit dl rm
serialport.py	2272	0644	edit dl rm
ssl.py	8643	0644	edit dl rm
stdio.py	1000	0644	edit dl rm
task.py	33608	0644	edit dl rm
tcp.py	54980	0644	edit dl rm
testing.py	29232	0644	edit dl rm
threads.py	3812	0644	edit dl rm
tksupport.py	1971	0644	edit dl rm
udp.py	18619	0644	edit dl rm
unix.py	22508	0644	edit dl rm
utils.py	8682	0644	edit dl rm
win32eventreactor.py	15266	0644	edit dl rm
wxreactor.py	5315	0644	edit dl rm
wxsupport.py	1305	0644	edit dl rm
_baseprocess.py	2003	0644	edit dl rm
_dumbwin32proc.py	12776	0644	edit dl rm
_glibbase.py	12706	0644	edit dl rm
_idna.py	1422	0644	edit dl rm
_newtls.py	9157	0644	edit dl rm
_pollingfile.py	8791	0644	edit dl rm
_posixserialport.py	2081	0644	edit dl rm
_posixstdio.py	4996	0644	edit dl rm
_producer_helpers.py	3909	0644	edit dl rm
_resolver.py	8465	0644	edit dl rm
_signals.py	2670	0644	edit dl rm
_sslverify.py	72796	0644	edit dl rm
_threadedselect.py	11582	0644	edit dl rm
_win32serialport.py	4914	0644	edit dl rm
_win32stdio.py	3140	0644	edit dl rm
__init__.py	521	0644	edit dl rm

Edit: /usr/lib/python3/dist-packages/twisted/internet/asyncioreactor.py (11131B)

# -*- test-case-name: twisted.test.test_internet -*-
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

"""
asyncio-based reactor implementation.
"""

import errno
import sys
from asyncio import AbstractEventLoop, get_event_loop
from typing import Dict, Optional, Type

from zope.interface import implementer

from twisted.internet.abstract import FileDescriptor
from twisted.internet.interfaces import IReactorFDSet
from twisted.internet.posixbase import (
    _NO_FILEDESC,
    PosixReactorBase,
    _ContinuousPolling,
)
from twisted.logger import Logger
from twisted.python.log import callWithLogger

@implementer(IReactorFDSet)
class AsyncioSelectorReactor(PosixReactorBase):
    """
    Reactor running on top of L{asyncio.SelectorEventLoop}.

On POSIX platforms, the default event loop is
    L{asyncio.SelectorEventLoop}.
    On Windows, the default event loop on Python 3.7 and older
    is C{asyncio.WindowsSelectorEventLoop}, but on Python 3.8 and newer
    the default event loop is C{asyncio.WindowsProactorEventLoop} which
    is incompatible with L{AsyncioSelectorReactor}.
    Applications that use L{AsyncioSelectorReactor} on Windows
    with Python 3.8+ must call
    C{asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())}
    before instantiating and running L{AsyncioSelectorReactor}.
    """

_asyncClosed = False
    _log = Logger()

def __init__(self, eventloop: Optional[AbstractEventLoop] = None):
        if eventloop is None:
            _eventloop: AbstractEventLoop = get_event_loop()
        else:
            _eventloop = eventloop

# On Python 3.8+, asyncio.get_event_loop() on
        # Windows was changed to return a ProactorEventLoop
        # unless the loop policy has been changed.
        if sys.platform == "win32":
            from asyncio import ProactorEventLoop

if isinstance(_eventloop, ProactorEventLoop):
                raise TypeError(
                    f"ProactorEventLoop is not supported, got: {_eventloop}"
                )

self._asyncioEventloop: AbstractEventLoop = _eventloop
        self._writers: Dict[Type[FileDescriptor], int] = {}
        self._readers: Dict[Type[FileDescriptor], int] = {}
        self._continuousPolling = _ContinuousPolling(self)

self._scheduledAt = None
        self._timerHandle = None

super().__init__()

def _unregisterFDInAsyncio(self, fd):
        """
        Compensate for a bug in asyncio where it will not unregister a FD that
        it cannot handle in the epoll loop. It touches internal asyncio code.

A description of the bug by markrwilliams:

The C{add_writer} method of asyncio event loops isn't atomic because
        all the Selector classes in the selector module internally record a
        file object before passing it to the platform's selector
        implementation. If the platform's selector decides the file object
        isn't acceptable, the resulting exception doesn't cause the Selector to
        un-track the file object.

The failing/hanging stdio test goes through the following sequence of
        events (roughly):

* The first C{connection.write(intToByte(value))} call hits the asyncio
        reactor's C{addWriter} method.

* C{addWriter} calls the asyncio loop's C{add_writer} method, which
        happens to live on C{_BaseSelectorEventLoop}.

* The asyncio loop's C{add_writer} method checks if the file object has
        been registered before via the selector's C{get_key} method.

* It hasn't, so the KeyError block runs and calls the selector's
        register method

* Code examples that follow use EpollSelector, but the code flow holds
        true for any other selector implementation. The selector's register
        method first calls through to the next register method in the MRO

* That next method is always C{_BaseSelectorImpl.register} which
        creates a C{SelectorKey} instance for the file object, stores it under
        the file object's file descriptor, and then returns it.

* Control returns to the concrete selector implementation, which asks
        the operating system to track the file descriptor using the right API.

* The operating system refuses! An exception is raised that, in this
        case, the asyncio reactor handles by creating a C{_ContinuousPolling}
        object to watch the file descriptor.

* The second C{connection.write(intToByte(value))} call hits the
        asyncio reactor's C{addWriter} method, which hits the C{add_writer}
        method. But the loop's selector's get_key method now returns a
        C{SelectorKey}! Now the asyncio reactor's C{addWriter} method thinks
        the asyncio loop will watch the file descriptor, even though it won't.
        """
        try:
            self._asyncioEventloop._selector.unregister(fd)
        except BaseException:
            pass

def _readOrWrite(self, selectable, read):
        method = selectable.doRead if read else selectable.doWrite

if selectable.fileno() == -1:
            self._disconnectSelectable(selectable, _NO_FILEDESC, read)
            return

try:
            why = method()
        except Exception as e:
            why = e
            self._log.failure(None)
        if why:
            self._disconnectSelectable(selectable, why, read)

def addReader(self, reader):
        if reader in self._readers.keys() or reader in self._continuousPolling._readers:
            return

fd = reader.fileno()
        try:
            self._asyncioEventloop.add_reader(
                fd, callWithLogger, reader, self._readOrWrite, reader, True
            )
            self._readers[reader] = fd
        except OSError as e:
            self._unregisterFDInAsyncio(fd)
            if e.errno == errno.EPERM:
                # epoll(7) doesn't support certain file descriptors,
                # e.g. filesystem files, so for those we just poll
                # continuously:
                self._continuousPolling.addReader(reader)
            else:
                raise

def addWriter(self, writer):
        if writer in self._writers.keys() or writer in self._continuousPolling._writers:
            return

fd = writer.fileno()
        try:
            self._asyncioEventloop.add_writer(
                fd, callWithLogger, writer, self._readOrWrite, writer, False
            )
            self._writers[writer] = fd
        except PermissionError:
            self._unregisterFDInAsyncio(fd)
            # epoll(7) doesn't support certain file descriptors,
            # e.g. filesystem files, so for those we just poll
            # continuously:
            self._continuousPolling.addWriter(writer)
        except BrokenPipeError:
            # The kqueuereactor will raise this if there is a broken pipe
            self._unregisterFDInAsyncio(fd)
        except BaseException:
            self._unregisterFDInAsyncio(fd)
            raise

def removeReader(self, reader):

# First, see if they're trying to remove a reader that we don't have.
        if not (
            reader in self._readers.keys() or self._continuousPolling.isReading(reader)
        ):
            # We don't have it, so just return OK.
            return

# If it was a cont. polling reader, check there first.
        if self._continuousPolling.isReading(reader):
            self._continuousPolling.removeReader(reader)
            return

fd = reader.fileno()
        if fd == -1:
            # If the FD is -1, we want to know what its original FD was, to
            # remove it.
            fd = self._readers.pop(reader)
        else:
            self._readers.pop(reader)

self._asyncioEventloop.remove_reader(fd)

def removeWriter(self, writer):

# First, see if they're trying to remove a writer that we don't have.
        if not (
            writer in self._writers.keys() or self._continuousPolling.isWriting(writer)
        ):
            # We don't have it, so just return OK.
            return

# If it was a cont. polling writer, check there first.
        if self._continuousPolling.isWriting(writer):
            self._continuousPolling.removeWriter(writer)
            return

fd = writer.fileno()

if fd == -1:
            # If the FD is -1, we want to know what its original FD was, to
            # remove it.
            fd = self._writers.pop(writer)
        else:
            self._writers.pop(writer)

self._asyncioEventloop.remove_writer(fd)

def removeAll(self):
        return (
            self._removeAll(self._readers.keys(), self._writers.keys())
            + self._continuousPolling.removeAll()
        )

def getReaders(self):
        return list(self._readers.keys()) + self._continuousPolling.getReaders()

def getWriters(self):
        return list(self._writers.keys()) + self._continuousPolling.getWriters()

def iterate(self, timeout):
        self._asyncioEventloop.call_later(timeout + 0.01, self._asyncioEventloop.stop)
        self._asyncioEventloop.run_forever()

def run(self, installSignalHandlers=True):
        self.startRunning(installSignalHandlers=installSignalHandlers)
        self._asyncioEventloop.run_forever()
        if self._justStopped:
            self._justStopped = False

def stop(self):
        super().stop()
        # This will cause runUntilCurrent which in its turn
        # will call fireSystemEvent("shutdown")
        self.callLater(0, lambda: None)

def crash(self):
        super().crash()
        self._asyncioEventloop.stop()

def _onTimer(self):
        self._scheduledAt = None
        self.runUntilCurrent()
        self._reschedule()

def _reschedule(self):
        timeout = self.timeout()
        if timeout is not None:
            abs_time = self._asyncioEventloop.time() + timeout
            self._scheduledAt = abs_time
            if self._timerHandle is not None:
                self._timerHandle.cancel()
            self._timerHandle = self._asyncioEventloop.call_at(abs_time, self._onTimer)

def _moveCallLaterSooner(self, tple):
        PosixReactorBase._moveCallLaterSooner(self, tple)
        self._reschedule()

def callLater(self, seconds, f, *args, **kwargs):
        dc = PosixReactorBase.callLater(self, seconds, f, *args, **kwargs)
        abs_time = self._asyncioEventloop.time() + self.timeout()
        if self._scheduledAt is None or abs_time < self._scheduledAt:
            self._reschedule()
        return dc

def callFromThread(self, f, *args, **kwargs):
        g = lambda: self.callLater(0, f, *args, **kwargs)
        self._asyncioEventloop.call_soon_threadsafe(g)

def install(eventloop=None):
    """
    Install an asyncio-based reactor.

@param eventloop: The asyncio eventloop to wrap. If default, the global one
        is selected.
    """
    reactor = AsyncioSelectorReactor(eventloop)
    from twisted.internet.main import installReactor

installReactor(reactor)

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