Issue #22926: In debug mode, call_soon(), call_at() and call_later() methods of

asyncio.BaseEventLoop now use the identifier of the current thread to ensure
that they are called from the thread running the event loop.

Before, the get_event_loop() method was used to check the thread, and no
exception was raised when the thread had no event loop. Now the methods always
raise an exception in debug mode when called from the wrong thread. It should
help to notice misusage of the API.
This commit is contained in:
Victor Stinner 2014-12-26 21:07:52 +01:00
parent d7ff5a5375
commit 956de691f8
6 changed files with 89 additions and 62 deletions

View File

@ -22,6 +22,7 @@ import logging
import os
import socket
import subprocess
import threading
import time
import traceback
import sys
@ -168,7 +169,9 @@ class BaseEventLoop(events.AbstractEventLoop):
self._scheduled = []
self._default_executor = None
self._internal_fds = 0
self._running = False
# Identifier of the thread running the event loop, or None if the
# event loop is not running
self._owner = None
self._clock_resolution = time.get_clock_info('monotonic').resolution
self._exception_handler = None
self._debug = (not sys.flags.ignore_environment
@ -246,9 +249,9 @@ class BaseEventLoop(events.AbstractEventLoop):
def run_forever(self):
"""Run until stop() is called."""
self._check_closed()
if self._running:
if self.is_running():
raise RuntimeError('Event loop is running.')
self._running = True
self._owner = threading.get_ident()
try:
while True:
try:
@ -256,7 +259,7 @@ class BaseEventLoop(events.AbstractEventLoop):
except _StopError:
break
finally:
self._running = False
self._owner = None
def run_until_complete(self, future):
"""Run until the Future is done.
@ -311,7 +314,7 @@ class BaseEventLoop(events.AbstractEventLoop):
The event loop must not be running.
"""
if self._running:
if self.is_running():
raise RuntimeError("Cannot close a running event loop")
if self._closed:
return
@ -331,7 +334,7 @@ class BaseEventLoop(events.AbstractEventLoop):
def is_running(self):
"""Returns True if the event loop is running."""
return self._running
return (self._owner is not None)
def time(self):
"""Return the time according to the event loop's clock.
@ -373,7 +376,7 @@ class BaseEventLoop(events.AbstractEventLoop):
raise TypeError("coroutines cannot be used with call_at()")
self._check_closed()
if self._debug:
self._assert_is_current_event_loop()
self._check_thread()
timer = events.TimerHandle(when, callback, args, self)
if timer._source_traceback:
del timer._source_traceback[-1]
@ -391,17 +394,17 @@ class BaseEventLoop(events.AbstractEventLoop):
Any positional arguments after the callback will be passed to
the callback when it is called.
"""
handle = self._call_soon(callback, args, check_loop=True)
if self._debug:
self._check_thread()
handle = self._call_soon(callback, args)
if handle._source_traceback:
del handle._source_traceback[-1]
return handle
def _call_soon(self, callback, args, check_loop):
def _call_soon(self, callback, args):
if (coroutines.iscoroutine(callback)
or coroutines.iscoroutinefunction(callback)):
raise TypeError("coroutines cannot be used with call_soon()")
if self._debug and check_loop:
self._assert_is_current_event_loop()
self._check_closed()
handle = events.Handle(callback, args, self)
if handle._source_traceback:
@ -409,8 +412,8 @@ class BaseEventLoop(events.AbstractEventLoop):
self._ready.append(handle)
return handle
def _assert_is_current_event_loop(self):
"""Asserts that this event loop is the current event loop.
def _check_thread(self):
"""Check that the current thread is the thread running the event loop.
Non-thread-safe methods of this class make this assumption and will
likely behave incorrectly when the assumption is violated.
@ -418,18 +421,17 @@ class BaseEventLoop(events.AbstractEventLoop):
Should only be called when (self._debug == True). The caller is
responsible for checking this condition for performance reasons.
"""
try:
current = events.get_event_loop()
except RuntimeError:
if self._owner is None:
return
if current is not self:
thread_id = threading.get_ident()
if thread_id != self._owner:
raise RuntimeError(
"Non-thread-safe operation invoked on an event loop other "
"than the current one")
def call_soon_threadsafe(self, callback, *args):
"""Like call_soon(), but thread-safe."""
handle = self._call_soon(callback, args, check_loop=False)
handle = self._call_soon(callback, args)
if handle._source_traceback:
del handle._source_traceback[-1]
self._write_to_self()

View File

@ -383,7 +383,7 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
sock, protocol, waiter, extra)
def close(self):
if self._running:
if self.is_running():
raise RuntimeError("Cannot close a running event loop")
if self.is_closed():
return
@ -432,9 +432,7 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
self._ssock.setblocking(False)
self._csock.setblocking(False)
self._internal_fds += 1
# don't check the current loop because _make_self_pipe() is called
# from the event loop constructor
self._call_soon(self._loop_self_reading, (), check_loop=False)
self.call_soon(self._loop_self_reading)
def _loop_self_reading(self, f=None):
try:

View File

@ -68,7 +68,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
address, waiter, extra)
def close(self):
if self._running:
if self.is_running():
raise RuntimeError("Cannot close a running event loop")
if self.is_closed():
return

View File

@ -5,6 +5,7 @@ import logging
import math
import socket
import sys
import threading
import time
import unittest
from unittest import mock
@ -148,28 +149,71 @@ class BaseEventLoopTests(test_utils.TestCase):
# are really slow
self.assertLessEqual(dt, 0.9, dt)
def test_assert_is_current_event_loop(self):
def check_thread(self, loop, debug):
def cb():
pass
other_loop = base_events.BaseEventLoop()
other_loop._selector = mock.Mock()
asyncio.set_event_loop(other_loop)
loop.set_debug(debug)
if debug:
msg = ("Non-thread-safe operation invoked on an event loop other "
"than the current one")
with self.assertRaisesRegex(RuntimeError, msg):
loop.call_soon(cb)
with self.assertRaisesRegex(RuntimeError, msg):
loop.call_later(60, cb)
with self.assertRaisesRegex(RuntimeError, msg):
loop.call_at(loop.time() + 60, cb)
else:
loop.call_soon(cb)
loop.call_later(60, cb)
loop.call_at(loop.time() + 60, cb)
# raise RuntimeError if the event loop is different in debug mode
self.loop.set_debug(True)
with self.assertRaises(RuntimeError):
self.loop.call_soon(cb)
with self.assertRaises(RuntimeError):
self.loop.call_later(60, cb)
with self.assertRaises(RuntimeError):
self.loop.call_at(self.loop.time() + 60, cb)
def test_check_thread(self):
def check_in_thread(loop, event, debug, create_loop, fut):
# wait until the event loop is running
event.wait()
try:
if create_loop:
loop2 = base_events.BaseEventLoop()
try:
asyncio.set_event_loop(loop2)
self.check_thread(loop, debug)
finally:
asyncio.set_event_loop(None)
loop2.close()
else:
self.check_thread(loop, debug)
except Exception as exc:
loop.call_soon_threadsafe(fut.set_exception, exc)
else:
loop.call_soon_threadsafe(fut.set_result, None)
def test_thread(loop, debug, create_loop=False):
event = threading.Event()
fut = asyncio.Future(loop=loop)
loop.call_soon(event.set)
args = (loop, event, debug, create_loop, fut)
thread = threading.Thread(target=check_in_thread, args=args)
thread.start()
loop.run_until_complete(fut)
thread.join()
self.loop._process_events = mock.Mock()
self.loop._write_to_self = mock.Mock()
# raise RuntimeError if the thread has no event loop
test_thread(self.loop, True)
# check disabled if debug mode is disabled
self.loop.set_debug(False)
self.loop.call_soon(cb)
self.loop.call_later(60, cb)
self.loop.call_at(self.loop.time() + 60, cb)
test_thread(self.loop, False)
# raise RuntimeError if the event loop of the thread is not the called
# event loop
test_thread(self.loop, True, create_loop=True)
# check disabled if debug mode is disabled
test_thread(self.loop, False, create_loop=True)
def test_run_once_in_executor_handle(self):
def cb():

View File

@ -440,17 +440,16 @@ class BaseProactorEventLoopTests(test_utils.TestCase):
self.loop = EventLoop(self.proactor)
self.set_event_loop(self.loop, cleanup=False)
@mock.patch.object(BaseProactorEventLoop, '_call_soon')
@mock.patch.object(BaseProactorEventLoop, 'call_soon')
@mock.patch.object(BaseProactorEventLoop, '_socketpair')
def test_ctor(self, socketpair, _call_soon):
def test_ctor(self, socketpair, call_soon):
ssock, csock = socketpair.return_value = (
mock.Mock(), mock.Mock())
loop = BaseProactorEventLoop(self.proactor)
self.assertIs(loop._ssock, ssock)
self.assertIs(loop._csock, csock)
self.assertEqual(loop._internal_fds, 1)
_call_soon.assert_called_with(loop._loop_self_reading, (),
check_loop=False)
call_soon.assert_called_with(loop._loop_self_reading)
def test_close_self_pipe(self):
self.loop._close_self_pipe()

View File

@ -233,19 +233,12 @@ if sys.platform != 'win32':
def setUp(self):
policy = asyncio.get_event_loop_policy()
self.loop = policy.new_event_loop()
# ensure that the event loop is passed explicitly in asyncio
policy.set_event_loop(None)
self.set_event_loop(self.loop)
watcher = self.Watcher()
watcher.attach_loop(self.loop)
policy.set_child_watcher(watcher)
def tearDown(self):
policy = asyncio.get_event_loop_policy()
policy.set_child_watcher(None)
self.loop.close()
super().tearDown()
self.addCleanup(policy.set_child_watcher, None)
class SubprocessSafeWatcherTests(SubprocessWatcherMixin,
test_utils.TestCase):
@ -262,17 +255,8 @@ else:
class SubprocessProactorTests(SubprocessMixin, test_utils.TestCase):
def setUp(self):
policy = asyncio.get_event_loop_policy()
self.loop = asyncio.ProactorEventLoop()
# ensure that the event loop is passed explicitly in asyncio
policy.set_event_loop(None)
def tearDown(self):
policy = asyncio.get_event_loop_policy()
self.loop.close()
policy.set_event_loop(None)
super().tearDown()
self.set_event_loop(self.loop)
if __name__ == '__main__':