646 lines
23 KiB
Python
646 lines
23 KiB
Python
"""Selector and proactor event loops for Windows."""
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import _winapi
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import errno
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import math
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import socket
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import struct
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import weakref
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from . import events
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from . import base_subprocess
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from . import futures
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from . import proactor_events
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from . import selector_events
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from . import tasks
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from . import windows_utils
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from . import _overlapped
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from .coroutines import coroutine
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from .log import logger
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__all__ = ['SelectorEventLoop', 'ProactorEventLoop', 'IocpProactor',
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'DefaultEventLoopPolicy',
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]
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NULL = 0
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INFINITE = 0xffffffff
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ERROR_CONNECTION_REFUSED = 1225
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ERROR_CONNECTION_ABORTED = 1236
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class _OverlappedFuture(futures.Future):
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"""Subclass of Future which represents an overlapped operation.
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Cancelling it will immediately cancel the overlapped operation.
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"""
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def __init__(self, ov, *, loop=None):
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super().__init__(loop=loop)
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if self._source_traceback:
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del self._source_traceback[-1]
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self._ov = ov
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def _repr_info(self):
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info = super()._repr_info()
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if self._ov is not None:
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state = 'pending' if self._ov.pending else 'completed'
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info.insert(1, 'overlapped=<%s, %#x>' % (state, self._ov.address))
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return info
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def _cancel_overlapped(self):
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if self._ov is None:
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return
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try:
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self._ov.cancel()
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except OSError as exc:
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context = {
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'message': 'Cancelling an overlapped future failed',
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'exception': exc,
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'future': self,
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}
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if self._source_traceback:
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context['source_traceback'] = self._source_traceback
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self._loop.call_exception_handler(context)
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self._ov = None
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def cancel(self):
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self._cancel_overlapped()
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return super().cancel()
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def set_exception(self, exception):
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super().set_exception(exception)
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self._cancel_overlapped()
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def set_result(self, result):
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super().set_result(result)
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self._ov = None
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class _WaitHandleFuture(futures.Future):
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"""Subclass of Future which represents a wait handle."""
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def __init__(self, iocp, ov, handle, wait_handle, *, loop=None):
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super().__init__(loop=loop)
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if self._source_traceback:
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del self._source_traceback[-1]
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# iocp and ov are only used by cancel() to notify IocpProactor
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# that the wait was cancelled
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self._iocp = iocp
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self._ov = ov
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self._handle = handle
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self._wait_handle = wait_handle
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def _poll(self):
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# non-blocking wait: use a timeout of 0 millisecond
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return (_winapi.WaitForSingleObject(self._handle, 0) ==
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_winapi.WAIT_OBJECT_0)
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def _repr_info(self):
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info = super()._repr_info()
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info.insert(1, 'handle=%#x' % self._handle)
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if self._wait_handle:
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state = 'signaled' if self._poll() else 'waiting'
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info.insert(1, 'wait_handle=<%s, %#x>'
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% (state, self._wait_handle))
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return info
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def _unregister_wait(self):
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if self._wait_handle is None:
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return
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try:
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_overlapped.UnregisterWait(self._wait_handle)
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except OSError as exc:
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# ERROR_IO_PENDING is not an error, the wait was unregistered
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if exc.winerror != _overlapped.ERROR_IO_PENDING:
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context = {
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'message': 'Failed to unregister the wait handle',
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'exception': exc,
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'future': self,
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}
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if self._source_traceback:
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context['source_traceback'] = self._source_traceback
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self._loop.call_exception_handler(context)
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self._wait_handle = None
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self._iocp = None
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self._ov = None
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def cancel(self):
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result = super().cancel()
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if self._ov is not None:
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# signal the cancellation to the overlapped object
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_overlapped.PostQueuedCompletionStatus(self._iocp, True,
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0, self._ov.address)
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self._unregister_wait()
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return result
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def set_exception(self, exception):
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super().set_exception(exception)
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self._unregister_wait()
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def set_result(self, result):
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super().set_result(result)
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self._unregister_wait()
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class PipeServer(object):
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"""Class representing a pipe server.
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This is much like a bound, listening socket.
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"""
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def __init__(self, address):
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self._address = address
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self._free_instances = weakref.WeakSet()
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# initialize the pipe attribute before calling _server_pipe_handle()
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# because this function can raise an exception and the destructor calls
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# the close() method
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self._pipe = None
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self._accept_pipe_future = None
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self._pipe = self._server_pipe_handle(True)
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def _get_unconnected_pipe(self):
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# Create new instance and return previous one. This ensures
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# that (until the server is closed) there is always at least
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# one pipe handle for address. Therefore if a client attempt
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# to connect it will not fail with FileNotFoundError.
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tmp, self._pipe = self._pipe, self._server_pipe_handle(False)
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return tmp
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def _server_pipe_handle(self, first):
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# Return a wrapper for a new pipe handle.
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if self._address is None:
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return None
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flags = _winapi.PIPE_ACCESS_DUPLEX | _winapi.FILE_FLAG_OVERLAPPED
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if first:
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flags |= _winapi.FILE_FLAG_FIRST_PIPE_INSTANCE
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h = _winapi.CreateNamedPipe(
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self._address, flags,
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_winapi.PIPE_TYPE_MESSAGE | _winapi.PIPE_READMODE_MESSAGE |
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_winapi.PIPE_WAIT,
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_winapi.PIPE_UNLIMITED_INSTANCES,
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windows_utils.BUFSIZE, windows_utils.BUFSIZE,
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_winapi.NMPWAIT_WAIT_FOREVER, _winapi.NULL)
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pipe = windows_utils.PipeHandle(h)
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self._free_instances.add(pipe)
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return pipe
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def close(self):
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if self._accept_pipe_future is not None:
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self._accept_pipe_future.cancel()
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self._accept_pipe_future = None
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# Close all instances which have not been connected to by a client.
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if self._address is not None:
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for pipe in self._free_instances:
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pipe.close()
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self._pipe = None
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self._address = None
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self._free_instances.clear()
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__del__ = close
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class _WindowsSelectorEventLoop(selector_events.BaseSelectorEventLoop):
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"""Windows version of selector event loop."""
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def _socketpair(self):
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return windows_utils.socketpair()
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class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
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"""Windows version of proactor event loop using IOCP."""
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def __init__(self, proactor=None):
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if proactor is None:
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proactor = IocpProactor()
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super().__init__(proactor)
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def _socketpair(self):
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return windows_utils.socketpair()
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@coroutine
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def create_pipe_connection(self, protocol_factory, address):
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f = self._proactor.connect_pipe(address)
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pipe = yield from f
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protocol = protocol_factory()
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trans = self._make_duplex_pipe_transport(pipe, protocol,
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extra={'addr': address})
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return trans, protocol
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@coroutine
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def start_serving_pipe(self, protocol_factory, address):
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server = PipeServer(address)
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def loop_accept_pipe(f=None):
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pipe = None
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try:
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if f:
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pipe = f.result()
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server._free_instances.discard(pipe)
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protocol = protocol_factory()
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self._make_duplex_pipe_transport(
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pipe, protocol, extra={'addr': address})
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pipe = server._get_unconnected_pipe()
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if pipe is None:
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return
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f = self._proactor.accept_pipe(pipe)
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except OSError as exc:
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if pipe and pipe.fileno() != -1:
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self.call_exception_handler({
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'message': 'Pipe accept failed',
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'exception': exc,
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'pipe': pipe,
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})
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pipe.close()
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elif self._debug:
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logger.warning("Accept pipe failed on pipe %r",
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pipe, exc_info=True)
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except futures.CancelledError:
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if pipe:
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pipe.close()
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else:
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server._accept_pipe_future = f
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f.add_done_callback(loop_accept_pipe)
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self.call_soon(loop_accept_pipe)
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return [server]
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@coroutine
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def _make_subprocess_transport(self, protocol, args, shell,
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stdin, stdout, stderr, bufsize,
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extra=None, **kwargs):
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transp = _WindowsSubprocessTransport(self, protocol, args, shell,
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stdin, stdout, stderr, bufsize,
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extra=extra, **kwargs)
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try:
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yield from transp._post_init()
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except:
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transp.close()
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raise
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return transp
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class IocpProactor:
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"""Proactor implementation using IOCP."""
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def __init__(self, concurrency=0xffffffff):
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self._loop = None
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self._results = []
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self._iocp = _overlapped.CreateIoCompletionPort(
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_overlapped.INVALID_HANDLE_VALUE, NULL, 0, concurrency)
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self._cache = {}
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self._registered = weakref.WeakSet()
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self._stopped_serving = weakref.WeakSet()
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def __repr__(self):
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return ('<%s overlapped#=%s result#=%s>'
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% (self.__class__.__name__, len(self._cache),
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len(self._results)))
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def set_loop(self, loop):
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self._loop = loop
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def select(self, timeout=None):
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if not self._results:
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self._poll(timeout)
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tmp = self._results
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self._results = []
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return tmp
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def recv(self, conn, nbytes, flags=0):
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self._register_with_iocp(conn)
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ov = _overlapped.Overlapped(NULL)
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if isinstance(conn, socket.socket):
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ov.WSARecv(conn.fileno(), nbytes, flags)
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else:
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ov.ReadFile(conn.fileno(), nbytes)
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def finish_recv(trans, key, ov):
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try:
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return ov.getresult()
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except OSError as exc:
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if exc.winerror == _overlapped.ERROR_NETNAME_DELETED:
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raise ConnectionResetError(*exc.args)
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else:
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raise
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return self._register(ov, conn, finish_recv)
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def send(self, conn, buf, flags=0):
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self._register_with_iocp(conn)
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ov = _overlapped.Overlapped(NULL)
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if isinstance(conn, socket.socket):
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ov.WSASend(conn.fileno(), buf, flags)
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else:
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ov.WriteFile(conn.fileno(), buf)
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def finish_send(trans, key, ov):
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try:
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return ov.getresult()
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except OSError as exc:
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if exc.winerror == _overlapped.ERROR_NETNAME_DELETED:
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raise ConnectionResetError(*exc.args)
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else:
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raise
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return self._register(ov, conn, finish_send)
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def accept(self, listener):
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self._register_with_iocp(listener)
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conn = self._get_accept_socket(listener.family)
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ov = _overlapped.Overlapped(NULL)
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ov.AcceptEx(listener.fileno(), conn.fileno())
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def finish_accept(trans, key, ov):
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ov.getresult()
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# Use SO_UPDATE_ACCEPT_CONTEXT so getsockname() etc work.
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buf = struct.pack('@P', listener.fileno())
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conn.setsockopt(socket.SOL_SOCKET,
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_overlapped.SO_UPDATE_ACCEPT_CONTEXT, buf)
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conn.settimeout(listener.gettimeout())
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return conn, conn.getpeername()
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@coroutine
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def accept_coro(future, conn):
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# Coroutine closing the accept socket if the future is cancelled
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try:
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yield from future
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except futures.CancelledError:
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conn.close()
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raise
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future = self._register(ov, listener, finish_accept)
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coro = accept_coro(future, conn)
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tasks.async(coro, loop=self._loop)
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return future
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def connect(self, conn, address):
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self._register_with_iocp(conn)
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# The socket needs to be locally bound before we call ConnectEx().
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try:
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_overlapped.BindLocal(conn.fileno(), conn.family)
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except OSError as e:
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if e.winerror != errno.WSAEINVAL:
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raise
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# Probably already locally bound; check using getsockname().
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if conn.getsockname()[1] == 0:
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raise
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ov = _overlapped.Overlapped(NULL)
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ov.ConnectEx(conn.fileno(), address)
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def finish_connect(trans, key, ov):
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ov.getresult()
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# Use SO_UPDATE_CONNECT_CONTEXT so getsockname() etc work.
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conn.setsockopt(socket.SOL_SOCKET,
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_overlapped.SO_UPDATE_CONNECT_CONTEXT, 0)
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return conn
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return self._register(ov, conn, finish_connect)
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def accept_pipe(self, pipe):
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self._register_with_iocp(pipe)
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ov = _overlapped.Overlapped(NULL)
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ov.ConnectNamedPipe(pipe.fileno())
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def finish_accept_pipe(trans, key, ov):
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ov.getresult()
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return pipe
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# FIXME: Tulip issue 196: why do we need register=False?
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# See also the comment in the _register() method
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return self._register(ov, pipe, finish_accept_pipe,
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register=False)
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def connect_pipe(self, address):
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ov = _overlapped.Overlapped(NULL)
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ov.WaitNamedPipeAndConnect(address, self._iocp, ov.address)
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def finish_connect_pipe(err, handle, ov):
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# err, handle were arguments passed to PostQueuedCompletionStatus()
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# in a function run in a thread pool.
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if err == _overlapped.ERROR_SEM_TIMEOUT:
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# Connection did not succeed within time limit.
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msg = _overlapped.FormatMessage(err)
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raise ConnectionRefusedError(0, msg, None, err)
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elif err != 0:
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msg = _overlapped.FormatMessage(err)
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raise OSError(0, msg, None, err)
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else:
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return windows_utils.PipeHandle(handle)
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return self._register(ov, None, finish_connect_pipe,
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wait_for_post=True)
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def wait_for_handle(self, handle, timeout=None):
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"""Wait for a handle.
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Return a Future object. The result of the future is True if the wait
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completed, or False if the wait did not complete (on timeout).
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"""
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if timeout is None:
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ms = _winapi.INFINITE
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else:
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# RegisterWaitForSingleObject() has a resolution of 1 millisecond,
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# round away from zero to wait *at least* timeout seconds.
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ms = math.ceil(timeout * 1e3)
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# We only create ov so we can use ov.address as a key for the cache.
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ov = _overlapped.Overlapped(NULL)
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wh = _overlapped.RegisterWaitWithQueue(
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handle, self._iocp, ov.address, ms)
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f = _WaitHandleFuture(self._iocp, ov, handle, wh, loop=self._loop)
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if f._source_traceback:
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del f._source_traceback[-1]
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def finish_wait_for_handle(trans, key, ov):
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# Note that this second wait means that we should only use
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# this with handles types where a successful wait has no
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# effect. So events or processes are all right, but locks
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# or semaphores are not. Also note if the handle is
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# signalled and then quickly reset, then we may return
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# False even though we have not timed out.
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return f._poll()
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if f._poll():
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try:
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result = f._poll()
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except OSError as exc:
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f.set_exception(exc)
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else:
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f.set_result(result)
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self._cache[ov.address] = (f, ov, 0, finish_wait_for_handle)
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return f
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def _register_with_iocp(self, obj):
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# To get notifications of finished ops on this objects sent to the
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# completion port, were must register the handle.
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if obj not in self._registered:
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self._registered.add(obj)
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_overlapped.CreateIoCompletionPort(obj.fileno(), self._iocp, 0, 0)
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# XXX We could also use SetFileCompletionNotificationModes()
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# to avoid sending notifications to completion port of ops
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# that succeed immediately.
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def _register(self, ov, obj, callback,
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wait_for_post=False, register=True):
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# Return a future which will be set with the result of the
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# operation when it completes. The future's value is actually
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# the value returned by callback().
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f = _OverlappedFuture(ov, loop=self._loop)
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if f._source_traceback:
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del f._source_traceback[-1]
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if not ov.pending and not wait_for_post:
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# The operation has completed, so no need to postpone the
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# work. We cannot take this short cut if we need the
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# NumberOfBytes, CompletionKey values returned by
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# PostQueuedCompletionStatus().
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try:
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value = callback(None, None, ov)
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except OSError as e:
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f.set_exception(e)
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else:
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f.set_result(value)
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# Even if GetOverlappedResult() was called, we have to wait for the
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# notification of the completion in GetQueuedCompletionStatus().
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# Register the overlapped operation to keep a reference to the
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# OVERLAPPED object, otherwise the memory is freed and Windows may
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# read uninitialized memory.
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#
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# For an unknown reason, ConnectNamedPipe() behaves differently:
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# the completion is not notified by GetOverlappedResult() if we
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# already called GetOverlappedResult(). For this specific case, we
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# don't expect notification (register is set to False).
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else:
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register = True
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if register:
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# Register the overlapped operation for later. Note that
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# we only store obj to prevent it from being garbage
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# collected too early.
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self._cache[ov.address] = (f, ov, obj, callback)
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return f
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def _get_accept_socket(self, family):
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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
|