| """Selector and proactor event loops for Windows.""" |
| |
| import _winapi |
| import errno |
| import math |
| import socket |
| import struct |
| import subprocess |
| 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 .log import logger |
| from . import _overlapped |
| |
| |
| __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) |
| self.ov = ov |
| |
| def cancel(self): |
| try: |
| self.ov.cancel() |
| except OSError: |
| pass |
| return super().cancel() |
| |
| |
| class _WaitHandleFuture(futures.Future): |
| """Subclass of Future which represents a wait handle.""" |
| |
| def __init__(self, wait_handle, *, loop=None): |
| super().__init__(loop=loop) |
| self._wait_handle = wait_handle |
| |
| def cancel(self): |
| super().cancel() |
| try: |
| _overlapped.UnregisterWait(self._wait_handle) |
| except OSError as e: |
| if e.winerror != _overlapped.ERROR_IO_PENDING: |
| raise |
| |
| |
| 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() |
| 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): |
| # 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() |
| |
| @tasks.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 |
| |
| @tasks.coroutine |
| def start_serving_pipe(self, protocol_factory, address): |
| server = PipeServer(address) |
| |
| def loop(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() |
| except futures.CancelledError: |
| if pipe: |
| pipe.close() |
| else: |
| f.add_done_callback(loop) |
| |
| self.call_soon(loop) |
| return [server] |
| |
| @tasks.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 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(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) |
| |
| 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(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) |
| |
| 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() |
| |
| @tasks.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(trans, key, ov): |
| ov.getresult() |
| return pipe |
| |
| return self._register(ov, pipe, finish) |
| |
| def connect_pipe(self, address): |
| ov = _overlapped.Overlapped(NULL) |
| ov.WaitNamedPipeAndConnect(address, self._iocp, ov.address) |
| |
| def finish(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, 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(wh, loop=self._loop) |
| |
| def finish(trans, key, ov): |
| if not f.cancelled(): |
| try: |
| _overlapped.UnregisterWait(wh) |
| except OSError as e: |
| if e.winerror != _overlapped.ERROR_IO_PENDING: |
| raise |
| # 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 (_winapi.WaitForSingleObject(handle, 0) == |
| _winapi.WAIT_OBJECT_0) |
| |
| self._cache[ov.address] = (f, ov, None, finish) |
| 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): |
| # 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 ov.pending or wait_for_post: |
| # 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) |
| else: |
| # 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) |
| 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 |
| err, transferred, key, address = status |
| try: |
| f, ov, obj, callback = self._cache.pop(address) |
| except KeyError: |
| # 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) |
| ms = 0 |
| continue |
| if obj in self._stopped_serving: |
| f.cancel() |
| elif not f.cancelled(): |
| 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) |
| ms = 0 |
| |
| 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, (f, 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] |
| else: |
| try: |
| ov.cancel() |
| except OSError: |
| pass |
| |
| 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 |
| |
| |
| 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 |