import collections

import subprocess

import warnings

from . import protocols

from . import transports

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(f'pid={self._pid}')

if self._returncode is not None:

info.append(f'returncode={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(f'stdin={stdin.pipe}')

stdout = self._pipes.get(1)

stderr = self._pipes.get(2)

if stdout is not None and stderr is stdout:

info.append(f'stdout=stderr={stdout.pipe}')

else:

if stdout is not None:

info.append(f'stdout={stdout.pipe}')

if stderr is not None:

info.append(f'stderr={stderr.pipe}')

return '<{}>'.format(' '.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 and

# has the child process finished?

self._returncode is None and

# the child process has finished, but the

# transport hasn't been notified yet?

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

def __del__(self, _warn=warnings.warn):

if not self._closed:

_warn(f"unclosed transport {self!r}", 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()

async def _connect_pipes(self, waiter):

try:

proc = self._proc

loop = self._loop

if proc.stdin is not None:

_, pipe = await loop.connect_write_pipe(

lambda: WriteSubprocessPipeProto(self, 0),

proc.stdin)

self._pipes[0] = pipe

if proc.stdout is not None:

_, pipe = await loop.connect_read_pipe(

lambda: ReadSubprocessPipeProto(self, 1),

proc.stdout)

self._pipes[1] = pipe

if proc.stderr is not None:

_, pipe = await 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 (SystemExit, KeyboardInterrupt):

raise

except BaseException 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()

async 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 await 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:

# wake up futures waiting for wait()

for waiter in self._exit_waiters:

if not waiter.cancelled():

waiter.set_result(self._returncode)

self._exit_waiters = None

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 f'<{self.__class__.__name__} fd={self.fd} pipe={self.pipe!r}>'

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)