blob: 6763f0b7bdcff663798977a2040d5bdea8db0717 [file] [log] [blame]
"""Selector and proactor event loops for Windows."""
import _winapi
import errno
import math
import socket
import struct
import weakref
from . import events
from . import base_subprocess
from . import futures
from . import proactor_events
from . import selector_events
from . import tasks
from . import windows_utils
from . import _overlapped
from .coroutines import coroutine
from .log import logger
__all__ = ['SelectorEventLoop', 'ProactorEventLoop', 'IocpProactor',
'DefaultEventLoopPolicy',
]
NULL = 0
INFINITE = 0xffffffff
ERROR_CONNECTION_REFUSED = 1225
ERROR_CONNECTION_ABORTED = 1236
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, 'overlapped=<%s, %#x>' % (state, self._ov.address))
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):
self._cancel_overlapped()
return super().cancel()
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 _WaitHandleFuture(futures.Future):
"""Subclass of Future which represents a wait handle."""
def __init__(self, iocp, ov, handle, wait_handle, *, loop=None):
super().__init__(loop=loop)
if self._source_traceback:
del self._source_traceback[-1]
# iocp and ov are only used by cancel() to notify IocpProactor
# that the wait was cancelled
self._iocp = iocp
self._ov = ov
self._handle = handle
self._wait_handle = wait_handle
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.insert(1, 'handle=%#x' % self._handle)
if self._wait_handle:
state = 'signaled' if self._poll() else 'waiting'
info.insert(1, 'wait_handle=<%s, %#x>'
% (state, self._wait_handle))
return info
def _unregister_wait(self):
if self._wait_handle is None:
return
try:
_overlapped.UnregisterWait(self._wait_handle)
except OSError as exc:
# ERROR_IO_PENDING is not an error, the wait was unregistered
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)
self._wait_handle = None
self._iocp = None
self._ov = None
def cancel(self):
result = super().cancel()
if self._ov is not None:
# signal the cancellation to the overlapped object
_overlapped.PostQueuedCompletionStatus(self._iocp, True,
0, self._ov.address)
self._unregister_wait()
return result
def set_exception(self, exception):
super().set_exception(exception)
self._unregister_wait()
def set_result(self, result):
super().set_result(result)
self._unregister_wait()
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._address is None:
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 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."""
def _socketpair(self):
return windows_utils.socketpair()
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 _socketpair(self):
return windows_utils.socketpair()
@coroutine
def create_pipe_connection(self, protocol_factory, address):
f = self._proactor.connect_pipe(address)
pipe = yield from f
protocol = protocol_factory()
trans = self._make_duplex_pipe_transport(pipe, protocol,
extra={'addr': address})
return trans, protocol
@coroutine
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)
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 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)
except futures.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]
@coroutine
def _make_subprocess_transport(self, protocol, args, shell,
stdin, stdout, stderr, bufsize,
extra=None, **kwargs):
transp = _WindowsSubprocessTransport(self, protocol, args, shell,
stdin, stdout, stderr, bufsize,
extra=extra, **kwargs)
yield from transp._post_init()
return transp
class IocpProactor:
"""Proactor implementation using IOCP."""
def __init__(self, concurrency=0xffffffff):
self._loop = None
self._results = []
self._iocp = _overlapped.CreateIoCompletionPort(
_overlapped.INVALID_HANDLE_VALUE, NULL, 0, concurrency)
self._cache = {}
self._registered = weakref.WeakSet()
self._stopped_serving = weakref.WeakSet()
def __repr__(self):
return ('<%s overlapped#=%s result#=%s>'
% (self.__class__.__name__, len(self._cache),
len(self._results)))
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 = []
return tmp
def recv(self, conn, nbytes, flags=0):
self._register_with_iocp(conn)
ov = _overlapped.Overlapped(NULL)
if isinstance(conn, socket.socket):
ov.WSARecv(conn.fileno(), nbytes, flags)
else:
ov.ReadFile(conn.fileno(), nbytes)
def finish_recv(trans, key, ov):
try:
return ov.getresult()
except OSError as exc:
if exc.winerror == _overlapped.ERROR_NETNAME_DELETED:
raise ConnectionResetError(*exc.args)
else:
raise
return self._register(ov, conn, finish_recv)
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)
def finish_send(trans, key, ov):
try:
return ov.getresult()
except OSError as exc:
if exc.winerror == _overlapped.ERROR_NETNAME_DELETED:
raise ConnectionResetError(*exc.args)
else:
raise
return self._register(ov, conn, finish_send)
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()
@coroutine
def accept_coro(future, conn):
# Coroutine closing the accept socket if the future is cancelled
try:
yield from future
except futures.CancelledError:
conn.close()
raise
future = self._register(ov, listener, finish_accept)
coro = accept_coro(future, conn)
tasks.async(coro, loop=self._loop)
return future
def connect(self, conn, address):
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 accept_pipe(self, pipe):
self._register_with_iocp(pipe)
ov = _overlapped.Overlapped(NULL)
ov.ConnectNamedPipe(pipe.fileno())
def finish_accept_pipe(trans, key, ov):
ov.getresult()
return pipe
# FIXME: Tulip issue 196: why to we neeed register=False?
# See also the comment in the _register() method
return self._register(ov, pipe, finish_accept_pipe,
register=False)
def connect_pipe(self, address):
ov = _overlapped.Overlapped(NULL)
ov.WaitNamedPipeAndConnect(address, self._iocp, ov.address)
def finish_connect_pipe(err, handle, ov):
# err, handle were arguments passed to PostQueuedCompletionStatus()
# in a function run in a thread pool.
if err == _overlapped.ERROR_SEM_TIMEOUT:
# Connection did not succeed within time limit.
msg = _overlapped.FormatMessage(err)
raise ConnectionRefusedError(0, msg, None, err)
elif err != 0:
msg = _overlapped.FormatMessage(err)
raise OSError(0, msg, None, err)
else:
return windows_utils.PipeHandle(handle)
return self._register(ov, None, finish_connect_pipe, wait_for_post=True)
def wait_for_handle(self, handle, timeout=None):
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)
wh = _overlapped.RegisterWaitWithQueue(
handle, self._iocp, ov.address, ms)
f = _WaitHandleFuture(self._iocp, ov, handle, wh, 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()
if f._poll():
try:
result = f._poll()
except OSError as exc:
f.set_exception(exc)
else:
f.set_result(result)
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,
wait_for_post=False, register=True):
# 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 and not wait_for_post:
# 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.
#
# For an unknown reason, ConnectNamedPipe() behaves differently:
# the completion is not notified by GetOverlappedResult() if we
# already called GetOverlappedResult(). For this specific case, we
# don't expect notification (register is set to False).
else:
register = True
if register:
# 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 _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:
return
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)
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):
# Cancel remaining registered operations.
for address, (fut, ov, obj, callback) in list(self._cache.items()):
if obj is None:
# The operation was started with connect_pipe() which
# queues a task to Windows' thread pool. This cannot
# be cancelled, so just forget it.
del self._cache[address]
# FIXME: Tulip issue 196: remove this case, it should not happen
elif fut.done() and not fut.cancelled():
del self._cache[address]
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)
while self._cache:
if not self._poll(1):
logger.debug('taking long time to close proactor')
self._results = []
if self._iocp is not None:
_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 _WindowsDefaultEventLoopPolicy(events.BaseDefaultEventLoopPolicy):
_loop_factory = SelectorEventLoop
DefaultEventLoopPolicy = _WindowsDefaultEventLoopPolicy