1142 lines
39 KiB
Python
1142 lines
39 KiB
Python
"""Selector event loop for Unix with signal handling."""
|
|
|
|
import errno
|
|
import io
|
|
import os
|
|
import selectors
|
|
import signal
|
|
import socket
|
|
import stat
|
|
import subprocess
|
|
import sys
|
|
import threading
|
|
import warnings
|
|
|
|
|
|
from . import base_events
|
|
from . import base_subprocess
|
|
from . import constants
|
|
from . import coroutines
|
|
from . import events
|
|
from . import futures
|
|
from . import selector_events
|
|
from . import tasks
|
|
from . import transports
|
|
from .log import logger
|
|
|
|
|
|
__all__ = (
|
|
'SelectorEventLoop',
|
|
'AbstractChildWatcher', 'SafeChildWatcher',
|
|
'FastChildWatcher', 'DefaultEventLoopPolicy',
|
|
)
|
|
|
|
|
|
if sys.platform == 'win32': # pragma: no cover
|
|
raise ImportError('Signals are not really supported on Windows')
|
|
|
|
|
|
def _sighandler_noop(signum, frame):
|
|
"""Dummy signal handler."""
|
|
pass
|
|
|
|
|
|
class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
|
|
"""Unix event loop.
|
|
|
|
Adds signal handling and UNIX Domain Socket support to SelectorEventLoop.
|
|
"""
|
|
|
|
def __init__(self, selector=None):
|
|
super().__init__(selector)
|
|
self._signal_handlers = {}
|
|
|
|
def close(self):
|
|
super().close()
|
|
if not sys.is_finalizing():
|
|
for sig in list(self._signal_handlers):
|
|
self.remove_signal_handler(sig)
|
|
else:
|
|
if self._signal_handlers:
|
|
warnings.warn(f"Closing the loop {self!r} "
|
|
f"on interpreter shutdown "
|
|
f"stage, skipping signal handlers removal",
|
|
ResourceWarning,
|
|
source=self)
|
|
self._signal_handlers.clear()
|
|
|
|
def _process_self_data(self, data):
|
|
for signum in data:
|
|
if not signum:
|
|
# ignore null bytes written by _write_to_self()
|
|
continue
|
|
self._handle_signal(signum)
|
|
|
|
def add_signal_handler(self, sig, callback, *args):
|
|
"""Add a handler for a signal. UNIX only.
|
|
|
|
Raise ValueError if the signal number is invalid or uncatchable.
|
|
Raise RuntimeError if there is a problem setting up the handler.
|
|
"""
|
|
if (coroutines.iscoroutine(callback) or
|
|
coroutines.iscoroutinefunction(callback)):
|
|
raise TypeError("coroutines cannot be used "
|
|
"with add_signal_handler()")
|
|
self._check_signal(sig)
|
|
self._check_closed()
|
|
try:
|
|
# set_wakeup_fd() raises ValueError if this is not the
|
|
# main thread. By calling it early we ensure that an
|
|
# event loop running in another thread cannot add a signal
|
|
# handler.
|
|
signal.set_wakeup_fd(self._csock.fileno())
|
|
except (ValueError, OSError) as exc:
|
|
raise RuntimeError(str(exc))
|
|
|
|
handle = events.Handle(callback, args, self, None)
|
|
self._signal_handlers[sig] = handle
|
|
|
|
try:
|
|
# Register a dummy signal handler to ask Python to write the signal
|
|
# number in the wakup file descriptor. _process_self_data() will
|
|
# read signal numbers from this file descriptor to handle signals.
|
|
signal.signal(sig, _sighandler_noop)
|
|
|
|
# Set SA_RESTART to limit EINTR occurrences.
|
|
signal.siginterrupt(sig, False)
|
|
except OSError as exc:
|
|
del self._signal_handlers[sig]
|
|
if not self._signal_handlers:
|
|
try:
|
|
signal.set_wakeup_fd(-1)
|
|
except (ValueError, OSError) as nexc:
|
|
logger.info('set_wakeup_fd(-1) failed: %s', nexc)
|
|
|
|
if exc.errno == errno.EINVAL:
|
|
raise RuntimeError(f'sig {sig} cannot be caught')
|
|
else:
|
|
raise
|
|
|
|
def _handle_signal(self, sig):
|
|
"""Internal helper that is the actual signal handler."""
|
|
handle = self._signal_handlers.get(sig)
|
|
if handle is None:
|
|
return # Assume it's some race condition.
|
|
if handle._cancelled:
|
|
self.remove_signal_handler(sig) # Remove it properly.
|
|
else:
|
|
self._add_callback_signalsafe(handle)
|
|
|
|
def remove_signal_handler(self, sig):
|
|
"""Remove a handler for a signal. UNIX only.
|
|
|
|
Return True if a signal handler was removed, False if not.
|
|
"""
|
|
self._check_signal(sig)
|
|
try:
|
|
del self._signal_handlers[sig]
|
|
except KeyError:
|
|
return False
|
|
|
|
if sig == signal.SIGINT:
|
|
handler = signal.default_int_handler
|
|
else:
|
|
handler = signal.SIG_DFL
|
|
|
|
try:
|
|
signal.signal(sig, handler)
|
|
except OSError as exc:
|
|
if exc.errno == errno.EINVAL:
|
|
raise RuntimeError(f'sig {sig} cannot be caught')
|
|
else:
|
|
raise
|
|
|
|
if not self._signal_handlers:
|
|
try:
|
|
signal.set_wakeup_fd(-1)
|
|
except (ValueError, OSError) as exc:
|
|
logger.info('set_wakeup_fd(-1) failed: %s', exc)
|
|
|
|
return True
|
|
|
|
def _check_signal(self, sig):
|
|
"""Internal helper to validate a signal.
|
|
|
|
Raise ValueError if the signal number is invalid or uncatchable.
|
|
Raise RuntimeError if there is a problem setting up the handler.
|
|
"""
|
|
if not isinstance(sig, int):
|
|
raise TypeError(f'sig must be an int, not {sig!r}')
|
|
|
|
if not (1 <= sig < signal.NSIG):
|
|
raise ValueError(f'sig {sig} out of range(1, {signal.NSIG})')
|
|
|
|
def _make_read_pipe_transport(self, pipe, protocol, waiter=None,
|
|
extra=None):
|
|
return _UnixReadPipeTransport(self, pipe, protocol, waiter, extra)
|
|
|
|
def _make_write_pipe_transport(self, pipe, protocol, waiter=None,
|
|
extra=None):
|
|
return _UnixWritePipeTransport(self, pipe, protocol, waiter, extra)
|
|
|
|
async def _make_subprocess_transport(self, protocol, args, shell,
|
|
stdin, stdout, stderr, bufsize,
|
|
extra=None, **kwargs):
|
|
with events.get_child_watcher() as watcher:
|
|
waiter = self.create_future()
|
|
transp = _UnixSubprocessTransport(self, protocol, args, shell,
|
|
stdin, stdout, stderr, bufsize,
|
|
waiter=waiter, extra=extra,
|
|
**kwargs)
|
|
|
|
watcher.add_child_handler(transp.get_pid(),
|
|
self._child_watcher_callback, transp)
|
|
try:
|
|
await waiter
|
|
except Exception:
|
|
transp.close()
|
|
await transp._wait()
|
|
raise
|
|
|
|
return transp
|
|
|
|
def _child_watcher_callback(self, pid, returncode, transp):
|
|
self.call_soon_threadsafe(transp._process_exited, returncode)
|
|
|
|
async def create_unix_connection(
|
|
self, protocol_factory, path=None, *,
|
|
ssl=None, sock=None,
|
|
server_hostname=None,
|
|
ssl_handshake_timeout=None):
|
|
assert server_hostname is None or isinstance(server_hostname, str)
|
|
if ssl:
|
|
if server_hostname is None:
|
|
raise ValueError(
|
|
'you have to pass server_hostname when using ssl')
|
|
else:
|
|
if server_hostname is not None:
|
|
raise ValueError('server_hostname is only meaningful with ssl')
|
|
if ssl_handshake_timeout is not None:
|
|
raise ValueError(
|
|
'ssl_handshake_timeout is only meaningful with ssl')
|
|
|
|
if path is not None:
|
|
if sock is not None:
|
|
raise ValueError(
|
|
'path and sock can not be specified at the same time')
|
|
|
|
path = os.fspath(path)
|
|
sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM, 0)
|
|
try:
|
|
sock.setblocking(False)
|
|
await self.sock_connect(sock, path)
|
|
except:
|
|
sock.close()
|
|
raise
|
|
|
|
else:
|
|
if sock is None:
|
|
raise ValueError('no path and sock were specified')
|
|
if (sock.family != socket.AF_UNIX or
|
|
sock.type != socket.SOCK_STREAM):
|
|
raise ValueError(
|
|
f'A UNIX Domain Stream Socket was expected, got {sock!r}')
|
|
sock.setblocking(False)
|
|
|
|
transport, protocol = await self._create_connection_transport(
|
|
sock, protocol_factory, ssl, server_hostname,
|
|
ssl_handshake_timeout=ssl_handshake_timeout)
|
|
return transport, protocol
|
|
|
|
async def create_unix_server(
|
|
self, protocol_factory, path=None, *,
|
|
sock=None, backlog=100, ssl=None,
|
|
ssl_handshake_timeout=None,
|
|
start_serving=True):
|
|
if isinstance(ssl, bool):
|
|
raise TypeError('ssl argument must be an SSLContext or None')
|
|
|
|
if ssl_handshake_timeout is not None and not ssl:
|
|
raise ValueError(
|
|
'ssl_handshake_timeout is only meaningful with ssl')
|
|
|
|
if path is not None:
|
|
if sock is not None:
|
|
raise ValueError(
|
|
'path and sock can not be specified at the same time')
|
|
|
|
path = os.fspath(path)
|
|
sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
|
|
|
|
# Check for abstract socket. `str` and `bytes` paths are supported.
|
|
if path[0] not in (0, '\x00'):
|
|
try:
|
|
if stat.S_ISSOCK(os.stat(path).st_mode):
|
|
os.remove(path)
|
|
except FileNotFoundError:
|
|
pass
|
|
except OSError as err:
|
|
# Directory may have permissions only to create socket.
|
|
logger.error('Unable to check or remove stale UNIX socket '
|
|
'%r: %r', path, err)
|
|
|
|
try:
|
|
sock.bind(path)
|
|
except OSError as exc:
|
|
sock.close()
|
|
if exc.errno == errno.EADDRINUSE:
|
|
# Let's improve the error message by adding
|
|
# with what exact address it occurs.
|
|
msg = f'Address {path!r} is already in use'
|
|
raise OSError(errno.EADDRINUSE, msg) from None
|
|
else:
|
|
raise
|
|
except:
|
|
sock.close()
|
|
raise
|
|
else:
|
|
if sock is None:
|
|
raise ValueError(
|
|
'path was not specified, and no sock specified')
|
|
|
|
if (sock.family != socket.AF_UNIX or
|
|
sock.type != socket.SOCK_STREAM):
|
|
raise ValueError(
|
|
f'A UNIX Domain Stream Socket was expected, got {sock!r}')
|
|
|
|
sock.setblocking(False)
|
|
server = base_events.Server(self, [sock], protocol_factory,
|
|
ssl, backlog, ssl_handshake_timeout)
|
|
if start_serving:
|
|
server._start_serving()
|
|
# Skip one loop iteration so that all 'loop.add_reader'
|
|
# go through.
|
|
await tasks.sleep(0, loop=self)
|
|
|
|
return server
|
|
|
|
async def _sock_sendfile_native(self, sock, file, offset, count):
|
|
try:
|
|
os.sendfile
|
|
except AttributeError as exc:
|
|
raise events.SendfileNotAvailableError(
|
|
"os.sendfile() is not available")
|
|
try:
|
|
fileno = file.fileno()
|
|
except (AttributeError, io.UnsupportedOperation) as err:
|
|
raise events.SendfileNotAvailableError("not a regular file")
|
|
try:
|
|
fsize = os.fstat(fileno).st_size
|
|
except OSError as err:
|
|
raise events.SendfileNotAvailableError("not a regular file")
|
|
blocksize = count if count else fsize
|
|
if not blocksize:
|
|
return 0 # empty file
|
|
|
|
fut = self.create_future()
|
|
self._sock_sendfile_native_impl(fut, None, sock, fileno,
|
|
offset, count, blocksize, 0)
|
|
return await fut
|
|
|
|
def _sock_sendfile_native_impl(self, fut, registered_fd, sock, fileno,
|
|
offset, count, blocksize, total_sent):
|
|
fd = sock.fileno()
|
|
if registered_fd is not None:
|
|
# Remove the callback early. It should be rare that the
|
|
# selector says the fd is ready but the call still returns
|
|
# EAGAIN, and I am willing to take a hit in that case in
|
|
# order to simplify the common case.
|
|
self.remove_writer(registered_fd)
|
|
if fut.cancelled():
|
|
self._sock_sendfile_update_filepos(fileno, offset, total_sent)
|
|
return
|
|
if count:
|
|
blocksize = count - total_sent
|
|
if blocksize <= 0:
|
|
self._sock_sendfile_update_filepos(fileno, offset, total_sent)
|
|
fut.set_result(total_sent)
|
|
return
|
|
|
|
try:
|
|
sent = os.sendfile(fd, fileno, offset, blocksize)
|
|
except (BlockingIOError, InterruptedError):
|
|
if registered_fd is None:
|
|
self._sock_add_cancellation_callback(fut, sock)
|
|
self.add_writer(fd, self._sock_sendfile_native_impl, fut,
|
|
fd, sock, fileno,
|
|
offset, count, blocksize, total_sent)
|
|
except OSError as exc:
|
|
if (registered_fd is not None and
|
|
exc.errno == errno.ENOTCONN and
|
|
type(exc) is not ConnectionError):
|
|
# If we have an ENOTCONN and this isn't a first call to
|
|
# sendfile(), i.e. the connection was closed in the middle
|
|
# of the operation, normalize the error to ConnectionError
|
|
# to make it consistent across all Posix systems.
|
|
new_exc = ConnectionError(
|
|
"socket is not connected", errno.ENOTCONN)
|
|
new_exc.__cause__ = exc
|
|
exc = new_exc
|
|
if total_sent == 0:
|
|
# We can get here for different reasons, the main
|
|
# one being 'file' is not a regular mmap(2)-like
|
|
# file, in which case we'll fall back on using
|
|
# plain send().
|
|
err = events.SendfileNotAvailableError(
|
|
"os.sendfile call failed")
|
|
self._sock_sendfile_update_filepos(fileno, offset, total_sent)
|
|
fut.set_exception(err)
|
|
else:
|
|
self._sock_sendfile_update_filepos(fileno, offset, total_sent)
|
|
fut.set_exception(exc)
|
|
except Exception as exc:
|
|
self._sock_sendfile_update_filepos(fileno, offset, total_sent)
|
|
fut.set_exception(exc)
|
|
else:
|
|
if sent == 0:
|
|
# EOF
|
|
self._sock_sendfile_update_filepos(fileno, offset, total_sent)
|
|
fut.set_result(total_sent)
|
|
else:
|
|
offset += sent
|
|
total_sent += sent
|
|
if registered_fd is None:
|
|
self._sock_add_cancellation_callback(fut, sock)
|
|
self.add_writer(fd, self._sock_sendfile_native_impl, fut,
|
|
fd, sock, fileno,
|
|
offset, count, blocksize, total_sent)
|
|
|
|
def _sock_sendfile_update_filepos(self, fileno, offset, total_sent):
|
|
if total_sent > 0:
|
|
os.lseek(fileno, offset, os.SEEK_SET)
|
|
|
|
def _sock_add_cancellation_callback(self, fut, sock):
|
|
def cb(fut):
|
|
if fut.cancelled():
|
|
fd = sock.fileno()
|
|
if fd != -1:
|
|
self.remove_writer(fd)
|
|
fut.add_done_callback(cb)
|
|
|
|
|
|
class _UnixReadPipeTransport(transports.ReadTransport):
|
|
|
|
max_size = 256 * 1024 # max bytes we read in one event loop iteration
|
|
|
|
def __init__(self, loop, pipe, protocol, waiter=None, extra=None):
|
|
super().__init__(extra)
|
|
self._extra['pipe'] = pipe
|
|
self._loop = loop
|
|
self._pipe = pipe
|
|
self._fileno = pipe.fileno()
|
|
self._protocol = protocol
|
|
self._closing = False
|
|
|
|
mode = os.fstat(self._fileno).st_mode
|
|
if not (stat.S_ISFIFO(mode) or
|
|
stat.S_ISSOCK(mode) or
|
|
stat.S_ISCHR(mode)):
|
|
self._pipe = None
|
|
self._fileno = None
|
|
self._protocol = None
|
|
raise ValueError("Pipe transport is for pipes/sockets only.")
|
|
|
|
os.set_blocking(self._fileno, False)
|
|
|
|
self._loop.call_soon(self._protocol.connection_made, self)
|
|
# only start reading when connection_made() has been called
|
|
self._loop.call_soon(self._loop._add_reader,
|
|
self._fileno, self._read_ready)
|
|
if waiter is not None:
|
|
# only wake up the waiter when connection_made() has been called
|
|
self._loop.call_soon(futures._set_result_unless_cancelled,
|
|
waiter, None)
|
|
|
|
def __repr__(self):
|
|
info = [self.__class__.__name__]
|
|
if self._pipe is None:
|
|
info.append('closed')
|
|
elif self._closing:
|
|
info.append('closing')
|
|
info.append(f'fd={self._fileno}')
|
|
selector = getattr(self._loop, '_selector', None)
|
|
if self._pipe is not None and selector is not None:
|
|
polling = selector_events._test_selector_event(
|
|
selector, self._fileno, selectors.EVENT_READ)
|
|
if polling:
|
|
info.append('polling')
|
|
else:
|
|
info.append('idle')
|
|
elif self._pipe is not None:
|
|
info.append('open')
|
|
else:
|
|
info.append('closed')
|
|
return '<{}>'.format(' '.join(info))
|
|
|
|
def _read_ready(self):
|
|
try:
|
|
data = os.read(self._fileno, self.max_size)
|
|
except (BlockingIOError, InterruptedError):
|
|
pass
|
|
except OSError as exc:
|
|
self._fatal_error(exc, 'Fatal read error on pipe transport')
|
|
else:
|
|
if data:
|
|
self._protocol.data_received(data)
|
|
else:
|
|
if self._loop.get_debug():
|
|
logger.info("%r was closed by peer", self)
|
|
self._closing = True
|
|
self._loop._remove_reader(self._fileno)
|
|
self._loop.call_soon(self._protocol.eof_received)
|
|
self._loop.call_soon(self._call_connection_lost, None)
|
|
|
|
def pause_reading(self):
|
|
self._loop._remove_reader(self._fileno)
|
|
|
|
def resume_reading(self):
|
|
self._loop._add_reader(self._fileno, self._read_ready)
|
|
|
|
def set_protocol(self, protocol):
|
|
self._protocol = protocol
|
|
|
|
def get_protocol(self):
|
|
return self._protocol
|
|
|
|
def is_closing(self):
|
|
return self._closing
|
|
|
|
def close(self):
|
|
if not self._closing:
|
|
self._close(None)
|
|
|
|
def __del__(self):
|
|
if self._pipe is not None:
|
|
warnings.warn(f"unclosed transport {self!r}", ResourceWarning,
|
|
source=self)
|
|
self._pipe.close()
|
|
|
|
def _fatal_error(self, exc, message='Fatal error on pipe transport'):
|
|
# should be called by exception handler only
|
|
if (isinstance(exc, OSError) and exc.errno == errno.EIO):
|
|
if self._loop.get_debug():
|
|
logger.debug("%r: %s", self, message, exc_info=True)
|
|
else:
|
|
self._loop.call_exception_handler({
|
|
'message': message,
|
|
'exception': exc,
|
|
'transport': self,
|
|
'protocol': self._protocol,
|
|
})
|
|
self._close(exc)
|
|
|
|
def _close(self, exc):
|
|
self._closing = True
|
|
self._loop._remove_reader(self._fileno)
|
|
self._loop.call_soon(self._call_connection_lost, exc)
|
|
|
|
def _call_connection_lost(self, exc):
|
|
try:
|
|
self._protocol.connection_lost(exc)
|
|
finally:
|
|
self._pipe.close()
|
|
self._pipe = None
|
|
self._protocol = None
|
|
self._loop = None
|
|
|
|
|
|
class _UnixWritePipeTransport(transports._FlowControlMixin,
|
|
transports.WriteTransport):
|
|
|
|
def __init__(self, loop, pipe, protocol, waiter=None, extra=None):
|
|
super().__init__(extra, loop)
|
|
self._extra['pipe'] = pipe
|
|
self._pipe = pipe
|
|
self._fileno = pipe.fileno()
|
|
self._protocol = protocol
|
|
self._buffer = bytearray()
|
|
self._conn_lost = 0
|
|
self._closing = False # Set when close() or write_eof() called.
|
|
|
|
mode = os.fstat(self._fileno).st_mode
|
|
is_char = stat.S_ISCHR(mode)
|
|
is_fifo = stat.S_ISFIFO(mode)
|
|
is_socket = stat.S_ISSOCK(mode)
|
|
if not (is_char or is_fifo or is_socket):
|
|
self._pipe = None
|
|
self._fileno = None
|
|
self._protocol = None
|
|
raise ValueError("Pipe transport is only for "
|
|
"pipes, sockets and character devices")
|
|
|
|
os.set_blocking(self._fileno, False)
|
|
self._loop.call_soon(self._protocol.connection_made, self)
|
|
|
|
# On AIX, the reader trick (to be notified when the read end of the
|
|
# socket is closed) only works for sockets. On other platforms it
|
|
# works for pipes and sockets. (Exception: OS X 10.4? Issue #19294.)
|
|
if is_socket or (is_fifo and not sys.platform.startswith("aix")):
|
|
# only start reading when connection_made() has been called
|
|
self._loop.call_soon(self._loop._add_reader,
|
|
self._fileno, self._read_ready)
|
|
|
|
if waiter is not None:
|
|
# only wake up the waiter when connection_made() has been called
|
|
self._loop.call_soon(futures._set_result_unless_cancelled,
|
|
waiter, None)
|
|
|
|
def __repr__(self):
|
|
info = [self.__class__.__name__]
|
|
if self._pipe is None:
|
|
info.append('closed')
|
|
elif self._closing:
|
|
info.append('closing')
|
|
info.append(f'fd={self._fileno}')
|
|
selector = getattr(self._loop, '_selector', None)
|
|
if self._pipe is not None and selector is not None:
|
|
polling = selector_events._test_selector_event(
|
|
selector, self._fileno, selectors.EVENT_WRITE)
|
|
if polling:
|
|
info.append('polling')
|
|
else:
|
|
info.append('idle')
|
|
|
|
bufsize = self.get_write_buffer_size()
|
|
info.append(f'bufsize={bufsize}')
|
|
elif self._pipe is not None:
|
|
info.append('open')
|
|
else:
|
|
info.append('closed')
|
|
return '<{}>'.format(' '.join(info))
|
|
|
|
def get_write_buffer_size(self):
|
|
return len(self._buffer)
|
|
|
|
def _read_ready(self):
|
|
# Pipe was closed by peer.
|
|
if self._loop.get_debug():
|
|
logger.info("%r was closed by peer", self)
|
|
if self._buffer:
|
|
self._close(BrokenPipeError())
|
|
else:
|
|
self._close()
|
|
|
|
def write(self, data):
|
|
assert isinstance(data, (bytes, bytearray, memoryview)), repr(data)
|
|
if isinstance(data, bytearray):
|
|
data = memoryview(data)
|
|
if not data:
|
|
return
|
|
|
|
if self._conn_lost or self._closing:
|
|
if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES:
|
|
logger.warning('pipe closed by peer or '
|
|
'os.write(pipe, data) raised exception.')
|
|
self._conn_lost += 1
|
|
return
|
|
|
|
if not self._buffer:
|
|
# Attempt to send it right away first.
|
|
try:
|
|
n = os.write(self._fileno, data)
|
|
except (BlockingIOError, InterruptedError):
|
|
n = 0
|
|
except Exception as exc:
|
|
self._conn_lost += 1
|
|
self._fatal_error(exc, 'Fatal write error on pipe transport')
|
|
return
|
|
if n == len(data):
|
|
return
|
|
elif n > 0:
|
|
data = memoryview(data)[n:]
|
|
self._loop._add_writer(self._fileno, self._write_ready)
|
|
|
|
self._buffer += data
|
|
self._maybe_pause_protocol()
|
|
|
|
def _write_ready(self):
|
|
assert self._buffer, 'Data should not be empty'
|
|
|
|
try:
|
|
n = os.write(self._fileno, self._buffer)
|
|
except (BlockingIOError, InterruptedError):
|
|
pass
|
|
except Exception as exc:
|
|
self._buffer.clear()
|
|
self._conn_lost += 1
|
|
# Remove writer here, _fatal_error() doesn't it
|
|
# because _buffer is empty.
|
|
self._loop._remove_writer(self._fileno)
|
|
self._fatal_error(exc, 'Fatal write error on pipe transport')
|
|
else:
|
|
if n == len(self._buffer):
|
|
self._buffer.clear()
|
|
self._loop._remove_writer(self._fileno)
|
|
self._maybe_resume_protocol() # May append to buffer.
|
|
if self._closing:
|
|
self._loop._remove_reader(self._fileno)
|
|
self._call_connection_lost(None)
|
|
return
|
|
elif n > 0:
|
|
del self._buffer[:n]
|
|
|
|
def can_write_eof(self):
|
|
return True
|
|
|
|
def write_eof(self):
|
|
if self._closing:
|
|
return
|
|
assert self._pipe
|
|
self._closing = True
|
|
if not self._buffer:
|
|
self._loop._remove_reader(self._fileno)
|
|
self._loop.call_soon(self._call_connection_lost, None)
|
|
|
|
def set_protocol(self, protocol):
|
|
self._protocol = protocol
|
|
|
|
def get_protocol(self):
|
|
return self._protocol
|
|
|
|
def is_closing(self):
|
|
return self._closing
|
|
|
|
def close(self):
|
|
if self._pipe is not None and not self._closing:
|
|
# write_eof is all what we needed to close the write pipe
|
|
self.write_eof()
|
|
|
|
def __del__(self):
|
|
if self._pipe is not None:
|
|
warnings.warn(f"unclosed transport {self!r}", ResourceWarning,
|
|
source=self)
|
|
self._pipe.close()
|
|
|
|
def abort(self):
|
|
self._close(None)
|
|
|
|
def _fatal_error(self, exc, message='Fatal error on pipe transport'):
|
|
# should be called by exception handler only
|
|
if isinstance(exc, base_events._FATAL_ERROR_IGNORE):
|
|
if self._loop.get_debug():
|
|
logger.debug("%r: %s", self, message, exc_info=True)
|
|
else:
|
|
self._loop.call_exception_handler({
|
|
'message': message,
|
|
'exception': exc,
|
|
'transport': self,
|
|
'protocol': self._protocol,
|
|
})
|
|
self._close(exc)
|
|
|
|
def _close(self, exc=None):
|
|
self._closing = True
|
|
if self._buffer:
|
|
self._loop._remove_writer(self._fileno)
|
|
self._buffer.clear()
|
|
self._loop._remove_reader(self._fileno)
|
|
self._loop.call_soon(self._call_connection_lost, exc)
|
|
|
|
def _call_connection_lost(self, exc):
|
|
try:
|
|
self._protocol.connection_lost(exc)
|
|
finally:
|
|
self._pipe.close()
|
|
self._pipe = None
|
|
self._protocol = None
|
|
self._loop = None
|
|
|
|
|
|
class _UnixSubprocessTransport(base_subprocess.BaseSubprocessTransport):
|
|
|
|
def _start(self, args, shell, stdin, stdout, stderr, bufsize, **kwargs):
|
|
stdin_w = None
|
|
if stdin == subprocess.PIPE:
|
|
# Use a socket pair for stdin, since not all platforms
|
|
# support selecting read events on the write end of a
|
|
# socket (which we use in order to detect closing of the
|
|
# other end). Notably this is needed on AIX, and works
|
|
# just fine on other platforms.
|
|
stdin, stdin_w = socket.socketpair()
|
|
self._proc = subprocess.Popen(
|
|
args, shell=shell, stdin=stdin, stdout=stdout, stderr=stderr,
|
|
universal_newlines=False, bufsize=bufsize, **kwargs)
|
|
if stdin_w is not None:
|
|
stdin.close()
|
|
self._proc.stdin = open(stdin_w.detach(), 'wb', buffering=bufsize)
|
|
|
|
|
|
class AbstractChildWatcher:
|
|
"""Abstract base class for monitoring child processes.
|
|
|
|
Objects derived from this class monitor a collection of subprocesses and
|
|
report their termination or interruption by a signal.
|
|
|
|
New callbacks are registered with .add_child_handler(). Starting a new
|
|
process must be done within a 'with' block to allow the watcher to suspend
|
|
its activity until the new process if fully registered (this is needed to
|
|
prevent a race condition in some implementations).
|
|
|
|
Example:
|
|
with watcher:
|
|
proc = subprocess.Popen("sleep 1")
|
|
watcher.add_child_handler(proc.pid, callback)
|
|
|
|
Notes:
|
|
Implementations of this class must be thread-safe.
|
|
|
|
Since child watcher objects may catch the SIGCHLD signal and call
|
|
waitpid(-1), there should be only one active object per process.
|
|
"""
|
|
|
|
def add_child_handler(self, pid, callback, *args):
|
|
"""Register a new child handler.
|
|
|
|
Arrange for callback(pid, returncode, *args) to be called when
|
|
process 'pid' terminates. Specifying another callback for the same
|
|
process replaces the previous handler.
|
|
|
|
Note: callback() must be thread-safe.
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def remove_child_handler(self, pid):
|
|
"""Removes the handler for process 'pid'.
|
|
|
|
The function returns True if the handler was successfully removed,
|
|
False if there was nothing to remove."""
|
|
|
|
raise NotImplementedError()
|
|
|
|
def attach_loop(self, loop):
|
|
"""Attach the watcher to an event loop.
|
|
|
|
If the watcher was previously attached to an event loop, then it is
|
|
first detached before attaching to the new loop.
|
|
|
|
Note: loop may be None.
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def close(self):
|
|
"""Close the watcher.
|
|
|
|
This must be called to make sure that any underlying resource is freed.
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def __enter__(self):
|
|
"""Enter the watcher's context and allow starting new processes
|
|
|
|
This function must return self"""
|
|
raise NotImplementedError()
|
|
|
|
def __exit__(self, a, b, c):
|
|
"""Exit the watcher's context"""
|
|
raise NotImplementedError()
|
|
|
|
|
|
class BaseChildWatcher(AbstractChildWatcher):
|
|
|
|
def __init__(self):
|
|
self._loop = None
|
|
self._callbacks = {}
|
|
|
|
def close(self):
|
|
self.attach_loop(None)
|
|
|
|
def _do_waitpid(self, expected_pid):
|
|
raise NotImplementedError()
|
|
|
|
def _do_waitpid_all(self):
|
|
raise NotImplementedError()
|
|
|
|
def attach_loop(self, loop):
|
|
assert loop is None or isinstance(loop, events.AbstractEventLoop)
|
|
|
|
if self._loop is not None and loop is None and self._callbacks:
|
|
warnings.warn(
|
|
'A loop is being detached '
|
|
'from a child watcher with pending handlers',
|
|
RuntimeWarning)
|
|
|
|
if self._loop is not None:
|
|
self._loop.remove_signal_handler(signal.SIGCHLD)
|
|
|
|
self._loop = loop
|
|
if loop is not None:
|
|
loop.add_signal_handler(signal.SIGCHLD, self._sig_chld)
|
|
|
|
# Prevent a race condition in case a child terminated
|
|
# during the switch.
|
|
self._do_waitpid_all()
|
|
|
|
def _sig_chld(self):
|
|
try:
|
|
self._do_waitpid_all()
|
|
except Exception as exc:
|
|
# self._loop should always be available here
|
|
# as '_sig_chld' is added as a signal handler
|
|
# in 'attach_loop'
|
|
self._loop.call_exception_handler({
|
|
'message': 'Unknown exception in SIGCHLD handler',
|
|
'exception': exc,
|
|
})
|
|
|
|
def _compute_returncode(self, status):
|
|
if os.WIFSIGNALED(status):
|
|
# The child process died because of a signal.
|
|
return -os.WTERMSIG(status)
|
|
elif os.WIFEXITED(status):
|
|
# The child process exited (e.g sys.exit()).
|
|
return os.WEXITSTATUS(status)
|
|
else:
|
|
# The child exited, but we don't understand its status.
|
|
# This shouldn't happen, but if it does, let's just
|
|
# return that status; perhaps that helps debug it.
|
|
return status
|
|
|
|
|
|
class SafeChildWatcher(BaseChildWatcher):
|
|
"""'Safe' child watcher implementation.
|
|
|
|
This implementation avoids disrupting other code spawning processes by
|
|
polling explicitly each process in the SIGCHLD handler instead of calling
|
|
os.waitpid(-1).
|
|
|
|
This is a safe solution but it has a significant overhead when handling a
|
|
big number of children (O(n) each time SIGCHLD is raised)
|
|
"""
|
|
|
|
def close(self):
|
|
self._callbacks.clear()
|
|
super().close()
|
|
|
|
def __enter__(self):
|
|
return self
|
|
|
|
def __exit__(self, a, b, c):
|
|
pass
|
|
|
|
def add_child_handler(self, pid, callback, *args):
|
|
if self._loop is None:
|
|
raise RuntimeError(
|
|
"Cannot add child handler, "
|
|
"the child watcher does not have a loop attached")
|
|
|
|
self._callbacks[pid] = (callback, args)
|
|
|
|
# Prevent a race condition in case the child is already terminated.
|
|
self._do_waitpid(pid)
|
|
|
|
def remove_child_handler(self, pid):
|
|
try:
|
|
del self._callbacks[pid]
|
|
return True
|
|
except KeyError:
|
|
return False
|
|
|
|
def _do_waitpid_all(self):
|
|
|
|
for pid in list(self._callbacks):
|
|
self._do_waitpid(pid)
|
|
|
|
def _do_waitpid(self, expected_pid):
|
|
assert expected_pid > 0
|
|
|
|
try:
|
|
pid, status = os.waitpid(expected_pid, os.WNOHANG)
|
|
except ChildProcessError:
|
|
# The child process is already reaped
|
|
# (may happen if waitpid() is called elsewhere).
|
|
pid = expected_pid
|
|
returncode = 255
|
|
logger.warning(
|
|
"Unknown child process pid %d, will report returncode 255",
|
|
pid)
|
|
else:
|
|
if pid == 0:
|
|
# The child process is still alive.
|
|
return
|
|
|
|
returncode = self._compute_returncode(status)
|
|
if self._loop.get_debug():
|
|
logger.debug('process %s exited with returncode %s',
|
|
expected_pid, returncode)
|
|
|
|
try:
|
|
callback, args = self._callbacks.pop(pid)
|
|
except KeyError: # pragma: no cover
|
|
# May happen if .remove_child_handler() is called
|
|
# after os.waitpid() returns.
|
|
if self._loop.get_debug():
|
|
logger.warning("Child watcher got an unexpected pid: %r",
|
|
pid, exc_info=True)
|
|
else:
|
|
callback(pid, returncode, *args)
|
|
|
|
|
|
class FastChildWatcher(BaseChildWatcher):
|
|
"""'Fast' child watcher implementation.
|
|
|
|
This implementation reaps every terminated processes by calling
|
|
os.waitpid(-1) directly, possibly breaking other code spawning processes
|
|
and waiting for their termination.
|
|
|
|
There is no noticeable overhead when handling a big number of children
|
|
(O(1) each time a child terminates).
|
|
"""
|
|
def __init__(self):
|
|
super().__init__()
|
|
self._lock = threading.Lock()
|
|
self._zombies = {}
|
|
self._forks = 0
|
|
|
|
def close(self):
|
|
self._callbacks.clear()
|
|
self._zombies.clear()
|
|
super().close()
|
|
|
|
def __enter__(self):
|
|
with self._lock:
|
|
self._forks += 1
|
|
|
|
return self
|
|
|
|
def __exit__(self, a, b, c):
|
|
with self._lock:
|
|
self._forks -= 1
|
|
|
|
if self._forks or not self._zombies:
|
|
return
|
|
|
|
collateral_victims = str(self._zombies)
|
|
self._zombies.clear()
|
|
|
|
logger.warning(
|
|
"Caught subprocesses termination from unknown pids: %s",
|
|
collateral_victims)
|
|
|
|
def add_child_handler(self, pid, callback, *args):
|
|
assert self._forks, "Must use the context manager"
|
|
|
|
if self._loop is None:
|
|
raise RuntimeError(
|
|
"Cannot add child handler, "
|
|
"the child watcher does not have a loop attached")
|
|
|
|
with self._lock:
|
|
try:
|
|
returncode = self._zombies.pop(pid)
|
|
except KeyError:
|
|
# The child is running.
|
|
self._callbacks[pid] = callback, args
|
|
return
|
|
|
|
# The child is dead already. We can fire the callback.
|
|
callback(pid, returncode, *args)
|
|
|
|
def remove_child_handler(self, pid):
|
|
try:
|
|
del self._callbacks[pid]
|
|
return True
|
|
except KeyError:
|
|
return False
|
|
|
|
def _do_waitpid_all(self):
|
|
# Because of signal coalescing, we must keep calling waitpid() as
|
|
# long as we're able to reap a child.
|
|
while True:
|
|
try:
|
|
pid, status = os.waitpid(-1, os.WNOHANG)
|
|
except ChildProcessError:
|
|
# No more child processes exist.
|
|
return
|
|
else:
|
|
if pid == 0:
|
|
# A child process is still alive.
|
|
return
|
|
|
|
returncode = self._compute_returncode(status)
|
|
|
|
with self._lock:
|
|
try:
|
|
callback, args = self._callbacks.pop(pid)
|
|
except KeyError:
|
|
# unknown child
|
|
if self._forks:
|
|
# It may not be registered yet.
|
|
self._zombies[pid] = returncode
|
|
if self._loop.get_debug():
|
|
logger.debug('unknown process %s exited '
|
|
'with returncode %s',
|
|
pid, returncode)
|
|
continue
|
|
callback = None
|
|
else:
|
|
if self._loop.get_debug():
|
|
logger.debug('process %s exited with returncode %s',
|
|
pid, returncode)
|
|
|
|
if callback is None:
|
|
logger.warning(
|
|
"Caught subprocess termination from unknown pid: "
|
|
"%d -> %d", pid, returncode)
|
|
else:
|
|
callback(pid, returncode, *args)
|
|
|
|
|
|
class _UnixDefaultEventLoopPolicy(events.BaseDefaultEventLoopPolicy):
|
|
"""UNIX event loop policy with a watcher for child processes."""
|
|
_loop_factory = _UnixSelectorEventLoop
|
|
|
|
def __init__(self):
|
|
super().__init__()
|
|
self._watcher = None
|
|
|
|
def _init_watcher(self):
|
|
with events._lock:
|
|
if self._watcher is None: # pragma: no branch
|
|
self._watcher = SafeChildWatcher()
|
|
if isinstance(threading.current_thread(),
|
|
threading._MainThread):
|
|
self._watcher.attach_loop(self._local._loop)
|
|
|
|
def set_event_loop(self, loop):
|
|
"""Set the event loop.
|
|
|
|
As a side effect, if a child watcher was set before, then calling
|
|
.set_event_loop() from the main thread will call .attach_loop(loop) on
|
|
the child watcher.
|
|
"""
|
|
|
|
super().set_event_loop(loop)
|
|
|
|
if (self._watcher is not None and
|
|
isinstance(threading.current_thread(), threading._MainThread)):
|
|
self._watcher.attach_loop(loop)
|
|
|
|
def get_child_watcher(self):
|
|
"""Get the watcher for child processes.
|
|
|
|
If not yet set, a SafeChildWatcher object is automatically created.
|
|
"""
|
|
if self._watcher is None:
|
|
self._init_watcher()
|
|
|
|
return self._watcher
|
|
|
|
def set_child_watcher(self, watcher):
|
|
"""Set the watcher for child processes."""
|
|
|
|
assert watcher is None or isinstance(watcher, AbstractChildWatcher)
|
|
|
|
if self._watcher is not None:
|
|
self._watcher.close()
|
|
|
|
self._watcher = watcher
|
|
|
|
|
|
SelectorEventLoop = _UnixSelectorEventLoop
|
|
DefaultEventLoopPolicy = _UnixDefaultEventLoopPolicy
|