It no longer emits a deprecation warning if the current event loop was set.
Co-authored-by: Ćukasz Langa <lukasz@langa.pl>
Get the current event loop.
- If there is no current event loop set in the current OS thread,
- the OS thread is main, and :func:`set_event_loop` has not yet
- been called, asyncio will create a new event loop and set it as the
- current one.
+ When called from a coroutine or a callback (e.g. scheduled with
+ call_soon or similar API), this function will always return the
+ running event loop.
+
+ If there is no running event loop set, the function will return
+ the result of ``get_event_loop_policy().get_event_loop()`` call.
Because this function has rather complex behavior (especially
when custom event loop policies are in use), using the
event loop.
.. deprecated:: 3.10
- Emits a deprecation warning if there is no running event loop.
- In future Python releases, this function may become an alias of
- :func:`get_running_loop` and will accordingly raise a
- :exc:`RuntimeError` if there is no running event loop.
+ Deprecation warning is emitted if there is no current event loop.
+ In Python 3.12 it will be an error.
+
+ .. note::
+ In Python versions 3.10.0--3.10.8 and 3.11.0 this function
+ (and other functions which used it implicitly) emitted a
+ :exc:`DeprecationWarning` if there was no running event loop, even if
+ the current loop was set.
.. function:: set_event_loop(loop)
- The **preferred** function to get the running event loop.
* - :func:`asyncio.get_event_loop`
- - Get an event loop instance (current or via the policy).
+ - Get an event loop instance (running or current via the current policy).
* - :func:`asyncio.set_event_loop`
- Set the event loop as current via the current policy.
On Windows, :class:`ProactorEventLoop` is now used by default.
+ .. deprecated:: 3.11.1
+ :meth:`get_event_loop` now emits a :exc:`DeprecationWarning` if there
+ is no current event loop set and a new event loop has been implicitly
+ created. In Python 3.12 it will be an error.
+
.. class:: WindowsSelectorEventLoopPolicy
if (self._local._loop is None and
not self._local._set_called and
threading.current_thread() is threading.main_thread()):
+ stacklevel = 2
+ try:
+ f = sys._getframe(1)
+ except AttributeError:
+ pass
+ else:
+ while f:
+ module = f.f_globals.get('__name__')
+ if not (module == 'asyncio' or module.startswith('asyncio.')):
+ break
+ f = f.f_back
+ stacklevel += 1
+ import warnings
+ warnings.warn('There is no current event loop',
+ DeprecationWarning, stacklevel=stacklevel)
self.set_event_loop(self.new_event_loop())
if self._local._loop is None:
def _get_event_loop(stacklevel=3):
+ # This internal method is going away in Python 3.12, left here only for
+ # backwards compatibility with 3.10.0 - 3.10.8 and 3.11.0.
+ # Similarly, this method's C equivalent in _asyncio is going away as well.
+ # See GH-99949 for more details.
current_loop = _get_running_loop()
if current_loop is not None:
return current_loop
- import warnings
- warnings.warn('There is no current event loop',
- DeprecationWarning, stacklevel=stacklevel)
return get_event_loop_policy().get_event_loop()
def test_env_var_debug(self):
code = '\n'.join((
'import asyncio',
- 'loop = asyncio.get_event_loop()',
+ 'loop = asyncio.new_event_loop()',
'print(loop.get_debug())'))
# Test with -E to not fail if the unit test was run with
def test_get_event_loop(self):
policy = asyncio.DefaultEventLoopPolicy()
self.assertIsNone(policy._local._loop)
-
- loop = policy.get_event_loop()
+ with self.assertWarns(DeprecationWarning) as cm:
+ loop = policy.get_event_loop()
+ self.assertEqual(cm.filename, __file__)
self.assertIsInstance(loop, asyncio.AbstractEventLoop)
self.assertIs(policy._local._loop, loop)
policy, "set_event_loop",
wraps=policy.set_event_loop) as m_set_event_loop:
- loop = policy.get_event_loop()
+ with self.assertWarns(DeprecationWarning) as cm:
+ loop = policy.get_event_loop()
+ self.addCleanup(loop.close)
+ self.assertEqual(cm.filename, __file__)
# policy._local._loop must be set through .set_event_loop()
# (the unix DefaultEventLoopPolicy needs this call to attach
def test_set_event_loop(self):
policy = asyncio.DefaultEventLoopPolicy()
- old_loop = policy.get_event_loop()
+ old_loop = policy.new_event_loop()
+ policy.set_event_loop(old_loop)
self.assertRaises(TypeError, policy.set_event_loop, object())
asyncio.set_event_loop_policy(Policy())
loop = asyncio.new_event_loop()
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaises(TestError):
- asyncio.get_event_loop()
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaises(TestError):
+ asyncio.get_event_loop()
asyncio.set_event_loop(None)
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaises(TestError):
- asyncio.get_event_loop()
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaises(TestError):
+ asyncio.get_event_loop()
with self.assertRaisesRegex(RuntimeError, 'no running'):
asyncio.get_running_loop()
loop.run_until_complete(func())
asyncio.set_event_loop(loop)
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaises(TestError):
- asyncio.get_event_loop()
- self.assertEqual(cm.filename, __file__)
-
+ with self.assertRaises(TestError):
+ asyncio.get_event_loop()
asyncio.set_event_loop(None)
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaises(TestError):
- asyncio.get_event_loop()
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaises(TestError):
+ asyncio.get_event_loop()
finally:
asyncio.set_event_loop_policy(old_policy)
self.addCleanup(loop2.close)
self.assertEqual(cm.filename, __file__)
asyncio.set_event_loop(None)
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaisesRegex(RuntimeError, 'no current'):
- asyncio.get_event_loop()
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current'):
+ asyncio.get_event_loop()
with self.assertRaisesRegex(RuntimeError, 'no running'):
asyncio.get_running_loop()
loop.run_until_complete(func())
asyncio.set_event_loop(loop)
- with self.assertWarns(DeprecationWarning) as cm:
- self.assertIs(asyncio.get_event_loop(), loop)
- self.assertEqual(cm.filename, __file__)
+ self.assertIs(asyncio.get_event_loop(), loop)
asyncio.set_event_loop(None)
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaisesRegex(RuntimeError, 'no current'):
- asyncio.get_event_loop()
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current'):
+ asyncio.get_event_loop()
finally:
asyncio.set_event_loop_policy(old_policy)
self.assertTrue(f.cancelled())
def test_constructor_without_loop(self):
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaisesRegex(RuntimeError, 'There is no current event loop'):
- self._new_future()
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
+ self._new_future()
def test_constructor_use_running_loop(self):
async def test():
self.assertIs(f.get_loop(), self.loop)
def test_constructor_use_global_loop(self):
- # Deprecated in 3.10
+ # Deprecated in 3.10, undeprecated in 3.11.1
asyncio.set_event_loop(self.loop)
self.addCleanup(asyncio.set_event_loop, None)
- with self.assertWarns(DeprecationWarning) as cm:
- f = self._new_future()
- self.assertEqual(cm.filename, __file__)
+ f = self._new_future()
self.assertIs(f._loop, self.loop)
self.assertIs(f.get_loop(), self.loop)
return (arg, threading.get_ident())
ex = concurrent.futures.ThreadPoolExecutor(1)
f1 = ex.submit(run, 'oi')
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaises(RuntimeError):
- asyncio.wrap_future(f1)
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
+ asyncio.wrap_future(f1)
ex.shutdown(wait=True)
def test_wrap_future_use_running_loop(self):
ex.shutdown(wait=True)
def test_wrap_future_use_global_loop(self):
- # Deprecated in 3.10
+ # Deprecated in 3.10, undeprecated in 3.11.1
asyncio.set_event_loop(self.loop)
self.addCleanup(asyncio.set_event_loop, None)
def run(arg):
return (arg, threading.get_ident())
ex = concurrent.futures.ThreadPoolExecutor(1)
f1 = ex.submit(run, 'oi')
- with self.assertWarns(DeprecationWarning) as cm:
- f2 = asyncio.wrap_future(f1)
- self.assertEqual(cm.filename, __file__)
+ f2 = asyncio.wrap_future(f1)
self.assertIs(self.loop, f2._loop)
ex.shutdown(wait=True)
self.assertEqual(data, b'data')
def test_streamreader_constructor_without_loop(self):
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaisesRegex(RuntimeError, 'There is no current event loop'):
- asyncio.StreamReader()
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
+ asyncio.StreamReader()
def test_streamreader_constructor_use_running_loop(self):
# asyncio issue #184: Ensure that StreamReaderProtocol constructor
def test_streamreader_constructor_use_global_loop(self):
# asyncio issue #184: Ensure that StreamReaderProtocol constructor
# retrieves the current loop if the loop parameter is not set
- # Deprecated in 3.10
+ # Deprecated in 3.10, undeprecated in 3.11.1
self.addCleanup(asyncio.set_event_loop, None)
asyncio.set_event_loop(self.loop)
- with self.assertWarns(DeprecationWarning) as cm:
- reader = asyncio.StreamReader()
- self.assertEqual(cm.filename, __file__)
+ reader = asyncio.StreamReader()
self.assertIs(reader._loop, self.loop)
def test_streamreaderprotocol_constructor_without_loop(self):
reader = mock.Mock()
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaisesRegex(RuntimeError, 'There is no current event loop'):
- asyncio.StreamReaderProtocol(reader)
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
+ asyncio.StreamReaderProtocol(reader)
def test_streamreaderprotocol_constructor_use_running_loop(self):
# asyncio issue #184: Ensure that StreamReaderProtocol constructor
def test_streamreaderprotocol_constructor_use_global_loop(self):
# asyncio issue #184: Ensure that StreamReaderProtocol constructor
# retrieves the current loop if the loop parameter is not set
- # Deprecated in 3.10
+ # Deprecated in 3.10, undeprecated in 3.11.1
self.addCleanup(asyncio.set_event_loop, None)
asyncio.set_event_loop(self.loop)
reader = mock.Mock()
- with self.assertWarns(DeprecationWarning) as cm:
- protocol = asyncio.StreamReaderProtocol(reader)
- self.assertEqual(cm.filename, __file__)
+ protocol = asyncio.StreamReaderProtocol(reader)
self.assertIs(protocol._loop, self.loop)
def test_multiple_drain(self):
a = notmuch()
self.addCleanup(a.close)
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaisesRegex(RuntimeError, 'There is no current event loop'):
- asyncio.ensure_future(a)
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
+ asyncio.ensure_future(a)
async def test():
return asyncio.ensure_future(notmuch())
self.assertTrue(t.done())
self.assertEqual(t.result(), 'ok')
- # Deprecated in 3.10
+ # Deprecated in 3.10, undeprecated in 3.11.1
asyncio.set_event_loop(self.loop)
self.addCleanup(asyncio.set_event_loop, None)
- with self.assertWarns(DeprecationWarning) as cm:
- t = asyncio.ensure_future(notmuch())
- self.assertEqual(cm.filename, __file__)
+ t = asyncio.ensure_future(notmuch())
self.assertIs(t._loop, self.loop)
self.loop.run_until_complete(t)
self.assertTrue(t.done())
self.addCleanup(a.close)
futs = asyncio.as_completed([a])
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaisesRegex(RuntimeError, 'There is no current event loop'):
- list(futs)
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
+ list(futs)
def test_as_completed_coroutine_use_running_loop(self):
loop = self.new_test_loop()
inner = coro()
self.addCleanup(inner.close)
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaisesRegex(RuntimeError, 'There is no current event loop'):
- asyncio.shield(inner)
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
+ asyncio.shield(inner)
def test_shield_coroutine_use_running_loop(self):
async def coro():
self.assertEqual(res, 42)
def test_shield_coroutine_use_global_loop(self):
- # Deprecated in 3.10
+ # Deprecated in 3.10, undeprecated in 3.11.1
async def coro():
return 42
asyncio.set_event_loop(self.loop)
self.addCleanup(asyncio.set_event_loop, None)
- with self.assertWarns(DeprecationWarning) as cm:
- outer = asyncio.shield(coro())
- self.assertEqual(cm.filename, __file__)
+ outer = asyncio.shield(coro())
self.assertEqual(outer._loop, self.loop)
res = self.loop.run_until_complete(outer)
self.assertEqual(res, 42)
self.assertIsNone(asyncio.current_task(loop=self.loop))
def test_current_task_no_running_loop_implicit(self):
- with self.assertRaises(RuntimeError):
+ with self.assertRaisesRegex(RuntimeError, 'no running event loop'):
asyncio.current_task()
def test_current_task_with_implicit_loop(self):
return asyncio.gather(*args, **kwargs)
def test_constructor_empty_sequence_without_loop(self):
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaises(RuntimeError):
- asyncio.gather()
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
+ asyncio.gather()
def test_constructor_empty_sequence_use_running_loop(self):
async def gather():
self.assertEqual(fut.result(), [])
def test_constructor_empty_sequence_use_global_loop(self):
- # Deprecated in 3.10
+ # Deprecated in 3.10, undeprecated in 3.11.1
asyncio.set_event_loop(self.one_loop)
self.addCleanup(asyncio.set_event_loop, None)
- with self.assertWarns(DeprecationWarning) as cm:
- fut = asyncio.gather()
- self.assertEqual(cm.filename, __file__)
+ fut = asyncio.gather()
self.assertIsInstance(fut, asyncio.Future)
self.assertIs(fut._loop, self.one_loop)
self._run_loop(self.one_loop)
self.addCleanup(gen1.close)
gen2 = coro()
self.addCleanup(gen2.close)
- with self.assertWarns(DeprecationWarning) as cm:
- with self.assertRaises(RuntimeError):
- asyncio.gather(gen1, gen2)
- self.assertEqual(cm.filename, __file__)
+ with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
+ asyncio.gather(gen1, gen2)
def test_constructor_use_running_loop(self):
async def coro():
self.one_loop.run_until_complete(fut)
def test_constructor_use_global_loop(self):
- # Deprecated in 3.10
+ # Deprecated in 3.10, undeprecated in 3.11.1
async def coro():
return 'abc'
asyncio.set_event_loop(self.other_loop)
self.addCleanup(asyncio.set_event_loop, None)
gen1 = coro()
gen2 = coro()
- with self.assertWarns(DeprecationWarning) as cm:
- fut = asyncio.gather(gen1, gen2)
- self.assertEqual(cm.filename, __file__)
+ fut = asyncio.gather(gen1, gen2)
self.assertIs(fut._loop, self.other_loop)
self.other_loop.run_until_complete(fut)
def test_child_watcher_replace_mainloop_existing(self):
policy = self.create_policy()
- loop = policy.get_event_loop()
+ loop = policy.new_event_loop()
+ policy.set_event_loop(loop)
# Explicitly setup SafeChildWatcher,
# default ThreadedChildWatcher has no _loop property
def test_unawaited_warning_during_shutdown(self):
code = ("import asyncio\n"
"async def f(): pass\n"
- "asyncio.gather(f())\n")
+ "async def t(): asyncio.gather(f())\n"
+ "asyncio.run(t())\n")
assert_python_ok("-c", code)
code = ("import sys\n"
--- /dev/null
+:func:`asyncio.get_event_loop` now only emits a deprecation warning when a
+new event loop was created implicitly. It no longer emits a deprecation
+warning if the current event loop was set.
return loop;
}
- if (PyErr_WarnEx(PyExc_DeprecationWarning,
- "There is no current event loop",
- stacklevel))
- {
- return NULL;
- }
-
policy = PyObject_CallNoArgs(asyncio_get_event_loop_policy);
if (policy == NULL) {
return NULL;
return get_event_loop(1);
}
+// This internal method is going away in Python 3.12, left here only for
+// backwards compatibility with 3.10.0 - 3.10.8 and 3.11.0.
+// Similarly, this method's Python equivalent in asyncio.events is going
+// away as well.
+// See GH-99949 for more details.
/*[clinic input]
_asyncio._get_event_loop
stacklevel: int = 3