Edit: base_subprocess.py
import collections import subprocess import warnings from . import compat from . import protocols from . import transports from .coroutines import coroutine from .log import logger class BaseSubprocessTransport(transports.SubprocessTransport): def __init__(self, loop, protocol, args, shell, stdin, stdout, stderr, bufsize, waiter=None, extra=None, **kwargs): super().__init__(extra) self._closed = False self._protocol = protocol self._loop = loop self._proc = None self._pid = None self._returncode = None self._exit_waiters = [] self._pending_calls = collections.deque() self._pipes = {} self._finished = False if stdin == subprocess.PIPE: self._pipes[0] = None if stdout == subprocess.PIPE: self._pipes[1] = None if stderr == subprocess.PIPE: self._pipes[2] = None # Create the child process: set the _proc attribute try: self._start(args=args, shell=shell, stdin=stdin, stdout=stdout, stderr=stderr, bufsize=bufsize, **kwargs) except: self.close() raise self._pid = self._proc.pid self._extra['subprocess'] = self._proc if self._loop.get_debug(): if isinstance(args, (bytes, str)): program = args else: program = args[0] logger.debug('process %r created: pid %s', program, self._pid) self._loop.create_task(self._connect_pipes(waiter)) def __repr__(self): info = [self.__class__.__name__] if self._closed: info.append('closed') if self._pid is not None: info.append('pid=%s' % self._pid) if self._returncode is not None: info.append('returncode=%s' % self._returncode) elif self._pid is not None: info.append('running') else: info.append('not started') stdin = self._pipes.get(0) if stdin is not None: info.append('stdin=%s' % stdin.pipe) stdout = self._pipes.get(1) stderr = self._pipes.get(2) if stdout is not None and stderr is stdout: info.append('stdout=stderr=%s' % stdout.pipe) else: if stdout is not None: info.append('stdout=%s' % stdout.pipe) if stderr is not None: info.append('stderr=%s' % stderr.pipe) return '<%s>' % ' '.join(info) def _start(self, args, shell, stdin, stdout, stderr, bufsize, **kwargs): raise NotImplementedError def set_protocol(self, protocol): self._protocol = protocol def get_protocol(self): return self._protocol def is_closing(self): return self._closed def close(self): if self._closed: return self._closed = True for proto in self._pipes.values(): if proto is None: continue proto.pipe.close() if (self._proc is not None # the child process finished? and self._returncode is None # the child process finished but the transport was not notified yet? and self._proc.poll() is None ): if self._loop.get_debug(): logger.warning('Close running child process: kill %r', self) try: self._proc.kill() except ProcessLookupError: pass # Don't clear the _proc reference yet: _post_init() may still run # On Python 3.3 and older, objects with a destructor part of a reference # cycle are never destroyed. It's not more the case on Python 3.4 thanks # to the PEP 442. if compat.PY34: def __del__(self): if not self._closed: warnings.warn("unclosed transport %r" % self, ResourceWarning, source=self) self.close() def get_pid(self): return self._pid def get_returncode(self): return self._returncode def get_pipe_transport(self, fd): if fd in self._pipes: return self._pipes[fd].pipe else: return None def _check_proc(self): if self._proc is None: raise ProcessLookupError() def send_signal(self, signal): self._check_proc() self._proc.send_signal(signal) def terminate(self): self._check_proc() self._proc.terminate() def kill(self): self._check_proc() self._proc.kill() @coroutine def _connect_pipes(self, waiter): try: proc = self._proc loop = self._loop if proc.stdin is not None: _, pipe = yield from loop.connect_write_pipe( lambda: WriteSubprocessPipeProto(self, 0), proc.stdin) self._pipes[0] = pipe if proc.stdout is not None: _, pipe = yield from loop.connect_read_pipe( lambda: ReadSubprocessPipeProto(self, 1), proc.stdout) self._pipes[1] = pipe if proc.stderr is not None: _, pipe = yield from loop.connect_read_pipe( lambda: ReadSubprocessPipeProto(self, 2), proc.stderr) self._pipes[2] = pipe assert self._pending_calls is not None loop.call_soon(self._protocol.connection_made, self) for callback, data in self._pending_calls: loop.call_soon(callback, *data) self._pending_calls = None except Exception as exc: if waiter is not None and not waiter.cancelled(): waiter.set_exception(exc) else: if waiter is not None and not waiter.cancelled(): waiter.set_result(None) def _call(self, cb, *data): if self._pending_calls is not None: self._pending_calls.append((cb, data)) else: self._loop.call_soon(cb, *data) def _pipe_connection_lost(self, fd, exc): self._call(self._protocol.pipe_connection_lost, fd, exc) self._try_finish() def _pipe_data_received(self, fd, data): self._call(self._protocol.pipe_data_received, fd, data) def _process_exited(self, returncode): assert returncode is not None, returncode assert self._returncode is None, self._returncode if self._loop.get_debug(): logger.info('%r exited with return code %r', self, returncode) self._returncode = returncode if self._proc.returncode is None: # asyncio uses a child watcher: copy the status into the Popen # object. On Python 3.6, it is required to avoid a ResourceWarning. self._proc.returncode = returncode self._call(self._protocol.process_exited) self._try_finish() # wake up futures waiting for wait() for waiter in self._exit_waiters: if not waiter.cancelled(): waiter.set_result(returncode) self._exit_waiters = None @coroutine def _wait(self): """Wait until the process exit and return the process return code. This method is a coroutine.""" if self._returncode is not None: return self._returncode waiter = self._loop.create_future() self._exit_waiters.append(waiter) return (yield from waiter) def _try_finish(self): assert not self._finished if self._returncode is None: return if all(p is not None and p.disconnected for p in self._pipes.values()): self._finished = True self._call(self._call_connection_lost, None) def _call_connection_lost(self, exc): try: self._protocol.connection_lost(exc) finally: self._loop = None self._proc = None self._protocol = None class WriteSubprocessPipeProto(protocols.BaseProtocol): def __init__(self, proc, fd): self.proc = proc self.fd = fd self.pipe = None self.disconnected = False def connection_made(self, transport): self.pipe = transport def __repr__(self): return ('<%s fd=%s pipe=%r>' % (self.__class__.__name__, self.fd, self.pipe)) def connection_lost(self, exc): self.disconnected = True self.proc._pipe_connection_lost(self.fd, exc) self.proc = None def pause_writing(self): self.proc._protocol.pause_writing() def resume_writing(self): self.proc._protocol.resume_writing() class ReadSubprocessPipeProto(WriteSubprocessPipeProto, protocols.Protocol): def data_received(self, data): self.proc._pipe_data_received(self.fd, data)
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