mirror of
https://github.com/python/cpython.git
synced 2025-11-04 07:31:38 +00:00
438 lines
13 KiB
Python
438 lines
13 KiB
Python
"""Event loop and event loop policy."""
|
|
|
|
__all__ = ['AbstractEventLoopPolicy',
|
|
'AbstractEventLoop', 'AbstractServer',
|
|
'Handle', 'TimerHandle',
|
|
'get_event_loop_policy', 'set_event_loop_policy',
|
|
'get_event_loop', 'set_event_loop', 'new_event_loop',
|
|
'get_child_watcher', 'set_child_watcher',
|
|
]
|
|
|
|
import subprocess
|
|
import sys
|
|
import threading
|
|
import socket
|
|
|
|
from .log import logger
|
|
|
|
|
|
class Handle:
|
|
"""Object returned by callback registration methods."""
|
|
|
|
def __init__(self, callback, args):
|
|
self._callback = callback
|
|
self._args = args
|
|
self._cancelled = False
|
|
|
|
def __repr__(self):
|
|
res = 'Handle({}, {})'.format(self._callback, self._args)
|
|
if self._cancelled:
|
|
res += '<cancelled>'
|
|
return res
|
|
|
|
def cancel(self):
|
|
self._cancelled = True
|
|
|
|
def _run(self):
|
|
try:
|
|
self._callback(*self._args)
|
|
except Exception:
|
|
logger.exception('Exception in callback %s %r',
|
|
self._callback, self._args)
|
|
self = None # Needed to break cycles when an exception occurs.
|
|
|
|
|
|
def make_handle(callback, args):
|
|
# TODO: Inline this? Or make it a private EventLoop method?
|
|
assert not isinstance(callback, Handle), 'A Handle is not a callback'
|
|
return Handle(callback, args)
|
|
|
|
|
|
class TimerHandle(Handle):
|
|
"""Object returned by timed callback registration methods."""
|
|
|
|
def __init__(self, when, callback, args):
|
|
assert when is not None
|
|
super().__init__(callback, args)
|
|
|
|
self._when = when
|
|
|
|
def __repr__(self):
|
|
res = 'TimerHandle({}, {}, {})'.format(self._when,
|
|
self._callback,
|
|
self._args)
|
|
if self._cancelled:
|
|
res += '<cancelled>'
|
|
|
|
return res
|
|
|
|
def __hash__(self):
|
|
return hash(self._when)
|
|
|
|
def __lt__(self, other):
|
|
return self._when < other._when
|
|
|
|
def __le__(self, other):
|
|
if self._when < other._when:
|
|
return True
|
|
return self.__eq__(other)
|
|
|
|
def __gt__(self, other):
|
|
return self._when > other._when
|
|
|
|
def __ge__(self, other):
|
|
if self._when > other._when:
|
|
return True
|
|
return self.__eq__(other)
|
|
|
|
def __eq__(self, other):
|
|
if isinstance(other, TimerHandle):
|
|
return (self._when == other._when and
|
|
self._callback == other._callback and
|
|
self._args == other._args and
|
|
self._cancelled == other._cancelled)
|
|
return NotImplemented
|
|
|
|
def __ne__(self, other):
|
|
equal = self.__eq__(other)
|
|
return NotImplemented if equal is NotImplemented else not equal
|
|
|
|
|
|
class AbstractServer:
|
|
"""Abstract server returned by create_service()."""
|
|
|
|
def close(self):
|
|
"""Stop serving. This leaves existing connections open."""
|
|
return NotImplemented
|
|
|
|
def wait_closed(self):
|
|
"""Coroutine to wait until service is closed."""
|
|
return NotImplemented
|
|
|
|
|
|
class AbstractEventLoop:
|
|
"""Abstract event loop."""
|
|
|
|
# Running and stopping the event loop.
|
|
|
|
def run_forever(self):
|
|
"""Run the event loop until stop() is called."""
|
|
raise NotImplementedError
|
|
|
|
def run_until_complete(self, future):
|
|
"""Run the event loop until a Future is done.
|
|
|
|
Return the Future's result, or raise its exception.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def stop(self):
|
|
"""Stop the event loop as soon as reasonable.
|
|
|
|
Exactly how soon that is may depend on the implementation, but
|
|
no more I/O callbacks should be scheduled.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def is_running(self):
|
|
"""Return whether the event loop is currently running."""
|
|
raise NotImplementedError
|
|
|
|
def close(self):
|
|
"""Close the loop.
|
|
|
|
The loop should not be running.
|
|
|
|
This is idempotent and irreversible.
|
|
|
|
No other methods should be called after this one.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
# Methods scheduling callbacks. All these return Handles.
|
|
|
|
def call_soon(self, callback, *args):
|
|
return self.call_later(0, callback, *args)
|
|
|
|
def call_later(self, delay, callback, *args):
|
|
raise NotImplementedError
|
|
|
|
def call_at(self, when, callback, *args):
|
|
raise NotImplementedError
|
|
|
|
def time(self):
|
|
raise NotImplementedError
|
|
|
|
# Methods for interacting with threads.
|
|
|
|
def call_soon_threadsafe(self, callback, *args):
|
|
raise NotImplementedError
|
|
|
|
def run_in_executor(self, executor, callback, *args):
|
|
raise NotImplementedError
|
|
|
|
def set_default_executor(self, executor):
|
|
raise NotImplementedError
|
|
|
|
# Network I/O methods returning Futures.
|
|
|
|
def getaddrinfo(self, host, port, *, family=0, type=0, proto=0, flags=0):
|
|
raise NotImplementedError
|
|
|
|
def getnameinfo(self, sockaddr, flags=0):
|
|
raise NotImplementedError
|
|
|
|
def create_connection(self, protocol_factory, host=None, port=None, *,
|
|
ssl=None, family=0, proto=0, flags=0, sock=None,
|
|
local_addr=None, server_hostname=None):
|
|
raise NotImplementedError
|
|
|
|
def create_server(self, protocol_factory, host=None, port=None, *,
|
|
family=socket.AF_UNSPEC, flags=socket.AI_PASSIVE,
|
|
sock=None, backlog=100, ssl=None, reuse_address=None):
|
|
"""A coroutine which creates a TCP server bound to host and port.
|
|
|
|
The return value is a Server object which can be used to stop
|
|
the service.
|
|
|
|
If host is an empty string or None all interfaces are assumed
|
|
and a list of multiple sockets will be returned (most likely
|
|
one for IPv4 and another one for IPv6).
|
|
|
|
family can be set to either AF_INET or AF_INET6 to force the
|
|
socket to use IPv4 or IPv6. If not set it will be determined
|
|
from host (defaults to AF_UNSPEC).
|
|
|
|
flags is a bitmask for getaddrinfo().
|
|
|
|
sock can optionally be specified in order to use a preexisting
|
|
socket object.
|
|
|
|
backlog is the maximum number of queued connections passed to
|
|
listen() (defaults to 100).
|
|
|
|
ssl can be set to an SSLContext to enable SSL over the
|
|
accepted connections.
|
|
|
|
reuse_address tells the kernel to reuse a local socket in
|
|
TIME_WAIT state, without waiting for its natural timeout to
|
|
expire. If not specified will automatically be set to True on
|
|
UNIX.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def create_datagram_endpoint(self, protocol_factory,
|
|
local_addr=None, remote_addr=None, *,
|
|
family=0, proto=0, flags=0):
|
|
raise NotImplementedError
|
|
|
|
# Pipes and subprocesses.
|
|
|
|
def connect_read_pipe(self, protocol_factory, pipe):
|
|
"""Register read pipe in eventloop.
|
|
|
|
protocol_factory should instantiate object with Protocol interface.
|
|
pipe is file-like object already switched to nonblocking.
|
|
Return pair (transport, protocol), where transport support
|
|
ReadTransport ABC"""
|
|
# The reason to accept file-like object instead of just file descriptor
|
|
# is: we need to own pipe and close it at transport finishing
|
|
# Can got complicated errors if pass f.fileno(),
|
|
# close fd in pipe transport then close f and vise versa.
|
|
raise NotImplementedError
|
|
|
|
def connect_write_pipe(self, protocol_factory, pipe):
|
|
"""Register write pipe in eventloop.
|
|
|
|
protocol_factory should instantiate object with BaseProtocol interface.
|
|
Pipe is file-like object already switched to nonblocking.
|
|
Return pair (transport, protocol), where transport support
|
|
WriteTransport ABC"""
|
|
# The reason to accept file-like object instead of just file descriptor
|
|
# is: we need to own pipe and close it at transport finishing
|
|
# Can got complicated errors if pass f.fileno(),
|
|
# close fd in pipe transport then close f and vise versa.
|
|
raise NotImplementedError
|
|
|
|
def subprocess_shell(self, protocol_factory, cmd, *, stdin=subprocess.PIPE,
|
|
stdout=subprocess.PIPE, stderr=subprocess.PIPE,
|
|
**kwargs):
|
|
raise NotImplementedError
|
|
|
|
def subprocess_exec(self, protocol_factory, *args, stdin=subprocess.PIPE,
|
|
stdout=subprocess.PIPE, stderr=subprocess.PIPE,
|
|
**kwargs):
|
|
raise NotImplementedError
|
|
|
|
# Ready-based callback registration methods.
|
|
# The add_*() methods return None.
|
|
# The remove_*() methods return True if something was removed,
|
|
# False if there was nothing to delete.
|
|
|
|
def add_reader(self, fd, callback, *args):
|
|
raise NotImplementedError
|
|
|
|
def remove_reader(self, fd):
|
|
raise NotImplementedError
|
|
|
|
def add_writer(self, fd, callback, *args):
|
|
raise NotImplementedError
|
|
|
|
def remove_writer(self, fd):
|
|
raise NotImplementedError
|
|
|
|
# Completion based I/O methods returning Futures.
|
|
|
|
def sock_recv(self, sock, nbytes):
|
|
raise NotImplementedError
|
|
|
|
def sock_sendall(self, sock, data):
|
|
raise NotImplementedError
|
|
|
|
def sock_connect(self, sock, address):
|
|
raise NotImplementedError
|
|
|
|
def sock_accept(self, sock):
|
|
raise NotImplementedError
|
|
|
|
# Signal handling.
|
|
|
|
def add_signal_handler(self, sig, callback, *args):
|
|
raise NotImplementedError
|
|
|
|
def remove_signal_handler(self, sig):
|
|
raise NotImplementedError
|
|
|
|
|
|
class AbstractEventLoopPolicy:
|
|
"""Abstract policy for accessing the event loop."""
|
|
|
|
def get_event_loop(self):
|
|
"""XXX"""
|
|
raise NotImplementedError
|
|
|
|
def set_event_loop(self, loop):
|
|
"""XXX"""
|
|
raise NotImplementedError
|
|
|
|
def new_event_loop(self):
|
|
"""XXX"""
|
|
raise NotImplementedError
|
|
|
|
# Child processes handling (Unix only).
|
|
|
|
def get_child_watcher(self):
|
|
"""XXX"""
|
|
raise NotImplementedError
|
|
|
|
def set_child_watcher(self, watcher):
|
|
"""XXX"""
|
|
raise NotImplementedError
|
|
|
|
|
|
class BaseDefaultEventLoopPolicy(AbstractEventLoopPolicy):
|
|
"""Default policy implementation for accessing the event loop.
|
|
|
|
In this policy, each thread has its own event loop. However, we
|
|
only automatically create an event loop by default for the main
|
|
thread; other threads by default have no event loop.
|
|
|
|
Other policies may have different rules (e.g. a single global
|
|
event loop, or automatically creating an event loop per thread, or
|
|
using some other notion of context to which an event loop is
|
|
associated).
|
|
"""
|
|
|
|
_loop_factory = None
|
|
|
|
class _Local(threading.local):
|
|
_loop = None
|
|
_set_called = False
|
|
|
|
def __init__(self):
|
|
self._local = self._Local()
|
|
|
|
def get_event_loop(self):
|
|
"""Get the event loop.
|
|
|
|
This may be None or an instance of EventLoop.
|
|
"""
|
|
if (self._local._loop is None and
|
|
not self._local._set_called and
|
|
isinstance(threading.current_thread(), threading._MainThread)):
|
|
self._local._loop = self.new_event_loop()
|
|
assert self._local._loop is not None, \
|
|
('There is no current event loop in thread %r.' %
|
|
threading.current_thread().name)
|
|
return self._local._loop
|
|
|
|
def set_event_loop(self, loop):
|
|
"""Set the event loop."""
|
|
self._local._set_called = True
|
|
assert loop is None or isinstance(loop, AbstractEventLoop)
|
|
self._local._loop = loop
|
|
|
|
def new_event_loop(self):
|
|
"""Create a new event loop.
|
|
|
|
You must call set_event_loop() to make this the current event
|
|
loop.
|
|
"""
|
|
return self._loop_factory()
|
|
|
|
|
|
# Event loop policy. The policy itself is always global, even if the
|
|
# policy's rules say that there is an event loop per thread (or other
|
|
# notion of context). The default policy is installed by the first
|
|
# call to get_event_loop_policy().
|
|
_event_loop_policy = None
|
|
|
|
# Lock for protecting the on-the-fly creation of the event loop policy.
|
|
_lock = threading.Lock()
|
|
|
|
|
|
def _init_event_loop_policy():
|
|
global _event_loop_policy
|
|
with _lock:
|
|
if _event_loop_policy is None: # pragma: no branch
|
|
from . import DefaultEventLoopPolicy
|
|
_event_loop_policy = DefaultEventLoopPolicy()
|
|
|
|
|
|
def get_event_loop_policy():
|
|
"""XXX"""
|
|
if _event_loop_policy is None:
|
|
_init_event_loop_policy()
|
|
return _event_loop_policy
|
|
|
|
|
|
def set_event_loop_policy(policy):
|
|
"""XXX"""
|
|
global _event_loop_policy
|
|
assert policy is None or isinstance(policy, AbstractEventLoopPolicy)
|
|
_event_loop_policy = policy
|
|
|
|
|
|
def get_event_loop():
|
|
"""XXX"""
|
|
return get_event_loop_policy().get_event_loop()
|
|
|
|
|
|
def set_event_loop(loop):
|
|
"""XXX"""
|
|
get_event_loop_policy().set_event_loop(loop)
|
|
|
|
|
|
def new_event_loop():
|
|
"""XXX"""
|
|
return get_event_loop_policy().new_event_loop()
|
|
|
|
|
|
def get_child_watcher():
|
|
"""XXX"""
|
|
return get_event_loop_policy().get_child_watcher()
|
|
|
|
|
|
def set_child_watcher(watcher):
|
|
"""XXX"""
|
|
return get_event_loop_policy().set_child_watcher(watcher)
|