cpython/Lib/asyncio/subprocess.py

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__all__ = ['create_subprocess_exec', 'create_subprocess_shell']
import collections
import subprocess
from . import events
from . import futures
from . import protocols
from . import streams
from . import tasks
PIPE = subprocess.PIPE
STDOUT = subprocess.STDOUT
DEVNULL = subprocess.DEVNULL
class SubprocessStreamProtocol(streams.FlowControlMixin,
protocols.SubprocessProtocol):
"""Like StreamReaderProtocol, but for a subprocess."""
def __init__(self, limit, loop):
super().__init__(loop=loop)
self._limit = limit
self.stdin = self.stdout = self.stderr = None
self.waiter = futures.Future(loop=loop)
self._waiters = collections.deque()
self._transport = None
def connection_made(self, transport):
self._transport = transport
if transport.get_pipe_transport(1):
self.stdout = streams.StreamReader(limit=self._limit,
loop=self._loop)
if transport.get_pipe_transport(2):
self.stderr = streams.StreamReader(limit=self._limit,
loop=self._loop)
stdin = transport.get_pipe_transport(0)
if stdin is not None:
self.stdin = streams.StreamWriter(stdin,
protocol=self,
reader=None,
loop=self._loop)
self.waiter.set_result(None)
def pipe_data_received(self, fd, data):
if fd == 1:
reader = self.stdout
elif fd == 2:
reader = self.stderr
else:
reader = None
if reader is not None:
reader.feed_data(data)
def pipe_connection_lost(self, fd, exc):
if fd == 0:
pipe = self.stdin
if pipe is not None:
pipe.close()
self.connection_lost(exc)
return
if fd == 1:
reader = self.stdout
elif fd == 2:
reader = self.stderr
else:
reader = None
if reader != None:
if exc is None:
reader.feed_eof()
else:
reader.set_exception(exc)
def process_exited(self):
# wake up futures waiting for wait()
returncode = self._transport.get_returncode()
while self._waiters:
waiter = self._waiters.popleft()
waiter.set_result(returncode)
class Process:
def __init__(self, transport, protocol, loop):
self._transport = transport
self._protocol = protocol
self._loop = loop
self.stdin = protocol.stdin
self.stdout = protocol.stdout
self.stderr = protocol.stderr
self.pid = transport.get_pid()
@property
def returncode(self):
return self._transport.get_returncode()
@tasks.coroutine
def wait(self):
"""Wait until the process exit and return the process return code."""
returncode = self._transport.get_returncode()
if returncode is not None:
return returncode
waiter = futures.Future(loop=self._loop)
self._protocol._waiters.append(waiter)
yield from waiter
return waiter.result()
def _check_alive(self):
if self._transport.get_returncode() is not None:
raise ProcessLookupError()
def send_signal(self, signal):
self._check_alive()
self._transport.send_signal(signal)
def terminate(self):
self._check_alive()
self._transport.terminate()
def kill(self):
self._check_alive()
self._transport.kill()
@tasks.coroutine
def _feed_stdin(self, input):
self.stdin.write(input)
yield from self.stdin.drain()
self.stdin.close()
@tasks.coroutine
def _noop(self):
return None
@tasks.coroutine
def _read_stream(self, fd):
transport = self._transport.get_pipe_transport(fd)
if fd == 2:
stream = self.stderr
else:
assert fd == 1
stream = self.stdout
output = yield from stream.read()
transport.close()
return output
@tasks.coroutine
def communicate(self, input=None):
loop = self._transport._loop
if input:
stdin = self._feed_stdin(input)
else:
stdin = self._noop()
if self.stdout is not None:
stdout = self._read_stream(1)
else:
stdout = self._noop()
if self.stderr is not None:
stderr = self._read_stream(2)
else:
stderr = self._noop()
stdin, stdout, stderr = yield from tasks.gather(stdin, stdout, stderr,
loop=loop)
yield from self.wait()
return (stdout, stderr)
@tasks.coroutine
def create_subprocess_shell(cmd, stdin=None, stdout=None, stderr=None,
loop=None, limit=streams._DEFAULT_LIMIT, **kwds):
if loop is None:
loop = events.get_event_loop()
protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
loop=loop)
transport, protocol = yield from loop.subprocess_shell(
protocol_factory,
cmd, stdin=stdin, stdout=stdout,
stderr=stderr, **kwds)
yield from protocol.waiter
return Process(transport, protocol, loop)
@tasks.coroutine
def create_subprocess_exec(program, *args, stdin=None, stdout=None, stderr=None,
loop=None, limit=streams._DEFAULT_LIMIT, **kwds):
if loop is None:
loop = events.get_event_loop()
protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
loop=loop)
transport, protocol = yield from loop.subprocess_exec(
protocol_factory,
program, *args,
stdin=stdin, stdout=stdout,
stderr=stderr, **kwds)
yield from protocol.waiter
return Process(transport, protocol, loop)