| """Selector and proactor event loops for Windows.""" |
| |
| import _overlapped |
| import _winapi |
| import errno |
| 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', |
| ) |
| |
| |
| NULL = 0 |
| INFINITE = 0xffffffff |
| 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(self): |
| try: |
| assert self._self_reading_future is None |
| self.call_soon(self._loop_self_reading) |
| super().run_forever() |
| finally: |
| if self._self_reading_future is not None: |
| ov = self._self_reading_future._ov |
| self._self_reading_future.cancel() |
| # self_reading_future was just cancelled so if it hasn't been |
| # finished yet, it never will be (it's possible that it has |
| # already finished and its callback is waiting in the queue, |
| # where it could still happen if the event loop is restarted). |
| # Unregister it otherwise IocpProactor.close will wait for it |
| # forever |
| if ov is not None: |
| 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 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 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=0xffffffff): |
| 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 = [] |
| return tmp |
| |
| def _result(self, value): |
| fut = self._loop.create_future() |
| fut.set_result(value) |
| return fut |
| |
| 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'') |
| |
| def finish_recv(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 |
| |
| return self._register(ov, conn, finish_recv) |
| |
| 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) |
| |
| def finish_recv(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 |
| |
| return self._register(ov, conn, finish_recv) |
| |
| 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)) |
| |
| def finish_recv(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 |
| |
| return self._register(ov, conn, finish_recv) |
| |
| 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) |
| |
| def finish_send(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 |
| |
| return self._register(ov, conn, finish_send) |
| |
| 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 in (_overlapped.ERROR_NETNAME_DELETED, |
| _overlapped.ERROR_OPERATION_ABORTED): |
| 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() |
| |
| 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) |
| |
| def finish_sendfile(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 |
| return self._register(ov, sock, finish_sendfile) |
| |
| 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) |
| |
| # 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 address, (fut, ov, obj, callback) in list(self._cache.items()): |
| 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 |
