From 172c0f2752d8708b6dda7b42e6c5a3519420a4e8 Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Sun, 25 Apr 2021 13:40:44 +0300 Subject: [PATCH] bpo-39529: Deprecate creating new event loop in asyncio.get_event_loop() (GH-23554) asyncio.get_event_loop() emits now a deprecation warning when it creates a new event loop. In future releases it will became an alias of asyncio.get_running_loop(). --- Doc/library/asyncio-eventloop.rst | 5 + Doc/library/asyncio-future.rst | 12 + Doc/library/asyncio-task.rst | 17 + Doc/whatsnew/3.10.rst | 13 + Lib/asyncio/events.py | 11 +- Lib/asyncio/futures.py | 4 +- Lib/asyncio/streams.py | 14 +- Lib/asyncio/tasks.py | 42 ++- Lib/test/test_asyncio/test_events.py | 77 +++- Lib/test/test_asyncio/test_futures.py | 62 +++- Lib/test/test_asyncio/test_queues.py | 23 +- Lib/test/test_asyncio/test_streams.py | 53 ++- Lib/test/test_asyncio/test_tasks.py | 346 ++++++++++++------ .../2020-12-06-20-21-16.bpo-39529.9Zrg43.rst | 9 + Modules/_asynciomodule.c | 26 +- Modules/clinic/_asynciomodule.c.h | 41 ++- 16 files changed, 570 insertions(+), 185 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2020-12-06-20-21-16.bpo-39529.9Zrg43.rst diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst index 7de5a0ab259..ca91efec260 100644 --- a/Doc/library/asyncio-eventloop.rst +++ b/Doc/library/asyncio-eventloop.rst @@ -53,6 +53,11 @@ an event loop: Consider also using the :func:`asyncio.run` function instead of using lower level functions to manually create and close an event loop. + .. deprecated:: 3.10 + Deprecation warning is emitted if there is no running event loop. + If future Python releases this function will be an alias of + :func:`get_running_loop`. + .. function:: set_event_loop(loop) Set *loop* as a current event loop for the current OS thread. diff --git a/Doc/library/asyncio-future.rst b/Doc/library/asyncio-future.rst index 939d4c1a845..ef496a23f5c 100644 --- a/Doc/library/asyncio-future.rst +++ b/Doc/library/asyncio-future.rst @@ -57,12 +57,20 @@ Future Functions .. versionchanged:: 3.5.1 The function accepts any :term:`awaitable` object. + .. deprecated:: 3.10 + Deprecation warning is emitted if *obj* is not a Future-like object + and *loop* is not specified and there is no running event loop. + .. function:: wrap_future(future, *, loop=None) Wrap a :class:`concurrent.futures.Future` object in a :class:`asyncio.Future` object. + .. deprecated:: 3.10 + Deprecation warning is emitted if *future* is not a Future-like object + and *loop* is not specified and there is no running event loop. + Future Object ============= @@ -90,6 +98,10 @@ Future Object .. versionchanged:: 3.7 Added support for the :mod:`contextvars` module. + .. deprecated:: 3.10 + Deprecation warning is emitted if *loop* is not specified + and there is no running event loop. + .. method:: result() Return the result of the Future. diff --git a/Doc/library/asyncio-task.rst b/Doc/library/asyncio-task.rst index 1ca1b4a06d7..3f54ecb08ef 100644 --- a/Doc/library/asyncio-task.rst +++ b/Doc/library/asyncio-task.rst @@ -397,6 +397,11 @@ Running Tasks Concurrently If the *gather* itself is cancelled, the cancellation is propagated regardless of *return_exceptions*. + .. deprecated:: 3.10 + Deprecation warning is emitted if no positional arguments are provided + or not all positional arguments are Future-like objects + and there is no running event loop. + Shielding From Cancellation =========================== @@ -434,6 +439,10 @@ Shielding From Cancellation except CancelledError: res = None + .. deprecated:: 3.10 + Deprecation warning is emitted if *aw* is not Future-like object + and there is no running event loop. + Timeouts ======== @@ -593,6 +602,10 @@ Waiting Primitives earliest_result = await coro # ... + .. deprecated:: 3.10 + Deprecation warning is emitted if not all awaitable objects in the *aws* + iterable are Future-like objects and there is no running event loop. + Running in Threads ================== @@ -775,6 +788,10 @@ Task Object .. deprecated-removed:: 3.8 3.10 The *loop* parameter. + .. deprecated:: 3.10 + Deprecation warning is emitted if *loop* is not specified + and there is no running event loop. + .. method:: cancel(msg=None) Request the Task to be cancelled. diff --git a/Doc/whatsnew/3.10.rst b/Doc/whatsnew/3.10.rst index dac44cf03fa..ab0b46f9f2d 100644 --- a/Doc/whatsnew/3.10.rst +++ b/Doc/whatsnew/3.10.rst @@ -1349,6 +1349,19 @@ Deprecated scheduled for removal in Python 3.12. (Contributed by Erlend E. Aasland in :issue:`42264`.) +* :func:`asyncio.get_event_loop` emits now a deprecation warning if there is + no running event loop. In future it will be an alias of + :func:`~asyncio.get_running_loop`. + :mod:`asyncio` functions which implicitly create a :class:`~asyncio.Future` + or :class:`~asyncio.Task` objects emit now + a deprecation warning if there is no running event loop and no explicit + *loop* argument is passed: :func:`~asyncio.ensure_future`, + :func:`~asyncio.wrap_future`, :func:`~asyncio.gather`, + :func:`~asyncio.shield`, :func:`~asyncio.as_completed` and constructors of + :class:`~asyncio.Future`, :class:`~asyncio.Task`, + :class:`~asyncio.StreamReader`, :class:`~asyncio.StreamReaderProtocol`. + (Contributed by Serhiy Storchaka in :issue:`39529`.) + * The undocumented built-in function ``sqlite3.enable_shared_cache`` is now deprecated, scheduled for removal in Python 3.12. Its use is strongly discouraged by the SQLite3 documentation. See `the SQLite3 docs diff --git a/Lib/asyncio/events.py b/Lib/asyncio/events.py index 1a20f362ec3..b966ad26bf4 100644 --- a/Lib/asyncio/events.py +++ b/Lib/asyncio/events.py @@ -759,9 +759,16 @@ def get_event_loop(): the result of `get_event_loop_policy().get_event_loop()` call. """ # NOTE: this function is implemented in C (see _asynciomodule.c) + return _py__get_event_loop() + + +def _get_event_loop(stacklevel=3): 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() @@ -791,6 +798,7 @@ _py__get_running_loop = _get_running_loop _py__set_running_loop = _set_running_loop _py_get_running_loop = get_running_loop _py_get_event_loop = get_event_loop +_py__get_event_loop = _get_event_loop try: @@ -798,7 +806,7 @@ try: # functions in asyncio. Pure Python implementation is # about 4 times slower than C-accelerated. from _asyncio import (_get_running_loop, _set_running_loop, - get_running_loop, get_event_loop) + get_running_loop, get_event_loop, _get_event_loop) except ImportError: pass else: @@ -807,3 +815,4 @@ else: _c__set_running_loop = _set_running_loop _c_get_running_loop = get_running_loop _c_get_event_loop = get_event_loop + _c__get_event_loop = _get_event_loop diff --git a/Lib/asyncio/futures.py b/Lib/asyncio/futures.py index 2d22ef66c9c..10f8f0554e4 100644 --- a/Lib/asyncio/futures.py +++ b/Lib/asyncio/futures.py @@ -76,7 +76,7 @@ class Future: the default event loop. """ if loop is None: - self._loop = events.get_event_loop() + self._loop = events._get_event_loop() else: self._loop = loop self._callbacks = [] @@ -408,7 +408,7 @@ def wrap_future(future, *, loop=None): assert isinstance(future, concurrent.futures.Future), \ f'concurrent.futures.Future is expected, got {future!r}' if loop is None: - loop = events.get_event_loop() + loop = events._get_event_loop() new_future = loop.create_future() _chain_future(future, new_future) return new_future diff --git a/Lib/asyncio/streams.py b/Lib/asyncio/streams.py index 96a9f97200d..080d8a62cde 100644 --- a/Lib/asyncio/streams.py +++ b/Lib/asyncio/streams.py @@ -125,7 +125,7 @@ class FlowControlMixin(protocols.Protocol): def __init__(self, loop=None): if loop is None: - self._loop = events.get_event_loop() + self._loop = events._get_event_loop(stacklevel=4) else: self._loop = loop self._paused = False @@ -283,9 +283,13 @@ class StreamReaderProtocol(FlowControlMixin, protocols.Protocol): def __del__(self): # Prevent reports about unhandled exceptions. # Better than self._closed._log_traceback = False hack - closed = self._closed - if closed.done() and not closed.cancelled(): - closed.exception() + try: + closed = self._closed + except AttributeError: + pass # failed constructor + else: + if closed.done() and not closed.cancelled(): + closed.exception() class StreamWriter: @@ -381,7 +385,7 @@ class StreamReader: self._limit = limit if loop is None: - self._loop = events.get_event_loop() + self._loop = events._get_event_loop() else: self._loop = loop self._buffer = bytearray() diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py index 52f1e6629e2..9a9d0d6e3cc 100644 --- a/Lib/asyncio/tasks.py +++ b/Lib/asyncio/tasks.py @@ -549,7 +549,7 @@ def as_completed(fs, *, timeout=None): from .queues import Queue # Import here to avoid circular import problem. done = Queue() - loop = events.get_event_loop() + loop = events._get_event_loop() todo = {ensure_future(f, loop=loop) for f in set(fs)} timeout_handle = None @@ -616,23 +616,26 @@ def ensure_future(coro_or_future, *, loop=None): If the argument is a Future, it is returned directly. """ - if coroutines.iscoroutine(coro_or_future): - if loop is None: - loop = events.get_event_loop() - task = loop.create_task(coro_or_future) - if task._source_traceback: - del task._source_traceback[-1] - return task - elif futures.isfuture(coro_or_future): + return _ensure_future(coro_or_future, loop=loop) + + +def _ensure_future(coro_or_future, *, loop=None): + if futures.isfuture(coro_or_future): if loop is not None and loop is not futures._get_loop(coro_or_future): raise ValueError('The future belongs to a different loop than ' - 'the one specified as the loop argument') + 'the one specified as the loop argument') return coro_or_future - elif inspect.isawaitable(coro_or_future): - return ensure_future(_wrap_awaitable(coro_or_future), loop=loop) - else: - raise TypeError('An asyncio.Future, a coroutine or an awaitable is ' - 'required') + + if not coroutines.iscoroutine(coro_or_future): + if inspect.isawaitable(coro_or_future): + coro_or_future = _wrap_awaitable(coro_or_future) + else: + raise TypeError('An asyncio.Future, a coroutine or an awaitable ' + 'is required') + + if loop is None: + loop = events._get_event_loop(stacklevel=4) + return loop.create_task(coro_or_future) @types.coroutine @@ -655,7 +658,8 @@ class _GatheringFuture(futures.Future): cancelled. """ - def __init__(self, children, *, loop=None): + def __init__(self, children, *, loop): + assert loop is not None super().__init__(loop=loop) self._children = children self._cancel_requested = False @@ -706,7 +710,7 @@ def gather(*coros_or_futures, return_exceptions=False): gather won't cancel any other awaitables. """ if not coros_or_futures: - loop = events.get_event_loop() + loop = events._get_event_loop() outer = loop.create_future() outer.set_result([]) return outer @@ -773,7 +777,7 @@ def gather(*coros_or_futures, return_exceptions=False): loop = None for arg in coros_or_futures: if arg not in arg_to_fut: - fut = ensure_future(arg, loop=loop) + fut = _ensure_future(arg, loop=loop) if loop is None: loop = futures._get_loop(fut) if fut is not arg: @@ -823,7 +827,7 @@ def shield(arg): except CancelledError: res = None """ - inner = ensure_future(arg) + inner = _ensure_future(arg) if inner.done(): # Shortcut. return inner diff --git a/Lib/test/test_asyncio/test_events.py b/Lib/test/test_asyncio/test_events.py index 5511407ba53..55fc266cb71 100644 --- a/Lib/test/test_asyncio/test_events.py +++ b/Lib/test/test_asyncio/test_events.py @@ -2702,14 +2702,18 @@ class GetEventLoopTestsMixin: asyncio.set_event_loop_policy(Policy()) loop = asyncio.new_event_loop() - with self.assertRaises(TestError): - asyncio.get_event_loop() + with self.assertWarns(DeprecationWarning) as cm: + with self.assertRaises(TestError): + asyncio.get_event_loop() + self.assertEqual(cm.warnings[0].filename, __file__) asyncio.set_event_loop(None) - with self.assertRaises(TestError): - asyncio.get_event_loop() + with self.assertWarns(DeprecationWarning) as cm: + with self.assertRaises(TestError): + asyncio.get_event_loop() + self.assertEqual(cm.warnings[0].filename, __file__) with self.assertRaisesRegex(RuntimeError, 'no running'): - self.assertIs(asyncio.get_running_loop(), None) + asyncio.get_running_loop() self.assertIs(asyncio._get_running_loop(), None) async def func(): @@ -2720,12 +2724,16 @@ class GetEventLoopTestsMixin: loop.run_until_complete(func()) asyncio.set_event_loop(loop) - with self.assertRaises(TestError): - asyncio.get_event_loop() + with self.assertWarns(DeprecationWarning) as cm: + with self.assertRaises(TestError): + asyncio.get_event_loop() + self.assertEqual(cm.warnings[0].filename, __file__) asyncio.set_event_loop(None) - with self.assertRaises(TestError): - asyncio.get_event_loop() + with self.assertWarns(DeprecationWarning) as cm: + with self.assertRaises(TestError): + asyncio.get_event_loop() + self.assertEqual(cm.warnings[0].filename, __file__) finally: asyncio.set_event_loop_policy(old_policy) @@ -2733,7 +2741,56 @@ class GetEventLoopTestsMixin: loop.close() with self.assertRaisesRegex(RuntimeError, 'no running'): - self.assertIs(asyncio.get_running_loop(), None) + asyncio.get_running_loop() + + self.assertIs(asyncio._get_running_loop(), None) + + def test_get_event_loop_returns_running_loop2(self): + old_policy = asyncio.get_event_loop_policy() + try: + asyncio.set_event_loop_policy(asyncio.DefaultEventLoopPolicy()) + loop = asyncio.new_event_loop() + self.addCleanup(loop.close) + + with self.assertWarns(DeprecationWarning) as cm: + loop2 = asyncio.get_event_loop() + self.addCleanup(loop2.close) + self.assertEqual(cm.warnings[0].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.warnings[0].filename, __file__) + + with self.assertRaisesRegex(RuntimeError, 'no running'): + asyncio.get_running_loop() + self.assertIs(asyncio._get_running_loop(), None) + + async def func(): + self.assertIs(asyncio.get_event_loop(), loop) + self.assertIs(asyncio.get_running_loop(), loop) + self.assertIs(asyncio._get_running_loop(), 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.warnings[0].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.warnings[0].filename, __file__) + + finally: + asyncio.set_event_loop_policy(old_policy) + if loop is not None: + loop.close() + + with self.assertRaisesRegex(RuntimeError, 'no running'): + asyncio.get_running_loop() self.assertIs(asyncio._get_running_loop(), None) diff --git a/Lib/test/test_asyncio/test_futures.py b/Lib/test/test_asyncio/test_futures.py index ec00896cc62..fe3d44227c8 100644 --- a/Lib/test/test_asyncio/test_futures.py +++ b/Lib/test/test_asyncio/test_futures.py @@ -139,9 +139,26 @@ class BaseFutureTests: f.cancel() self.assertTrue(f.cancelled()) - def test_init_constructor_default_loop(self): + 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.warnings[0].filename, __file__) + + def test_constructor_use_running_loop(self): + async def test(): + return self._new_future() + f = self.loop.run_until_complete(test()) + self.assertIs(f._loop, self.loop) + self.assertIs(f.get_loop(), self.loop) + + def test_constructor_use_global_loop(self): + # Deprecated in 3.10 asyncio.set_event_loop(self.loop) - f = self._new_future() + self.addCleanup(asyncio.set_event_loop, None) + with self.assertWarns(DeprecationWarning) as cm: + f = self._new_future() + self.assertEqual(cm.warnings[0].filename, __file__) self.assertIs(f._loop, self.loop) self.assertIs(f.get_loop(), self.loop) @@ -472,16 +489,41 @@ class BaseFutureTests: f2 = asyncio.wrap_future(f1) self.assertIs(f1, f2) + def test_wrap_future_without_loop(self): + def run(arg): + 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.warnings[0].filename, __file__) + ex.shutdown(wait=True) + + def test_wrap_future_use_running_loop(self): + def run(arg): + return (arg, threading.get_ident()) + ex = concurrent.futures.ThreadPoolExecutor(1) + f1 = ex.submit(run, 'oi') + async def test(): + return asyncio.wrap_future(f1) + f2 = self.loop.run_until_complete(test()) + self.assertIs(self.loop, f2._loop) + ex.shutdown(wait=True) + def test_wrap_future_use_global_loop(self): - with mock.patch('asyncio.futures.events') as events: - events.get_event_loop = lambda: self.loop - def run(arg): - return (arg, threading.get_ident()) - ex = concurrent.futures.ThreadPoolExecutor(1) - f1 = ex.submit(run, 'oi') + # Deprecated in 3.10 + 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.assertIs(self.loop, f2._loop) - ex.shutdown(wait=True) + self.assertEqual(cm.warnings[0].filename, __file__) + self.assertIs(self.loop, f2._loop) + ex.shutdown(wait=True) def test_wrap_future_cancel(self): f1 = concurrent.futures.Future() diff --git a/Lib/test/test_asyncio/test_queues.py b/Lib/test/test_asyncio/test_queues.py index 0a0b529f621..63a9a5f270c 100644 --- a/Lib/test/test_asyncio/test_queues.py +++ b/Lib/test/test_asyncio/test_queues.py @@ -273,12 +273,12 @@ class QueueGetTests(_QueueTestBase): queue._get_loop() return queue - q = self.loop.run_until_complete(create_queue()) + async def test(): + q = await create_queue() + await asyncio.gather(producer(q, producer_num_items), + consumer(q, producer_num_items)) - self.loop.run_until_complete( - asyncio.gather(producer(q, producer_num_items), - consumer(q, producer_num_items)), - ) + self.loop.run_until_complete(test()) def test_cancelled_getters_not_being_held_in_self_getters(self): def a_generator(): @@ -516,11 +516,14 @@ class QueuePutTests(_QueueTestBase): for _ in range(num): item = queue.get_nowait() - t0 = putter(0) - t1 = putter(1) - t2 = putter(2) - t3 = putter(3) - self.loop.run_until_complete(asyncio.gather(getter(), t0, t1, t2, t3)) + async def test(): + t0 = putter(0) + t1 = putter(1) + t2 = putter(2) + t3 = putter(3) + await asyncio.gather(getter(), t0, t1, t2, t3) + + self.loop.run_until_complete(test()) def test_cancelled_puts_not_being_held_in_self_putters(self): def a_generator(): diff --git a/Lib/test/test_asyncio/test_streams.py b/Lib/test/test_asyncio/test_streams.py index a0753589039..6eaa2899442 100644 --- a/Lib/test/test_asyncio/test_streams.py +++ b/Lib/test/test_asyncio/test_streams.py @@ -40,11 +40,6 @@ class StreamTests(test_utils.TestCase): gc.collect() super().tearDown() - @mock.patch('asyncio.streams.events') - def test_ctor_global_loop(self, m_events): - stream = asyncio.StreamReader() - self.assertIs(stream._loop, m_events.get_event_loop.return_value) - def _basetest_open_connection(self, open_connection_fut): messages = [] self.loop.set_exception_handler(lambda loop, ctx: messages.append(ctx)) @@ -751,23 +746,59 @@ os.close(fd) data = self.loop.run_until_complete(reader.read(-1)) self.assertEqual(data, b'data') - def test_streamreader_constructor(self): - self.addCleanup(asyncio.set_event_loop, None) - asyncio.set_event_loop(self.loop) + 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.warnings[0].filename, __file__) + def test_streamreader_constructor_use_running_loop(self): # asyncio issue #184: Ensure that StreamReaderProtocol constructor # retrieves the current loop if the loop parameter is not set - reader = asyncio.StreamReader() + async def test(): + return asyncio.StreamReader() + + reader = self.loop.run_until_complete(test()) self.assertIs(reader._loop, self.loop) - def test_streamreaderprotocol_constructor(self): + 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 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.warnings[0].filename, __file__) + 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.warnings[0].filename, __file__) + + def test_streamreaderprotocol_constructor_use_running_loop(self): # asyncio issue #184: Ensure that StreamReaderProtocol constructor # retrieves the current loop if the loop parameter is not set reader = mock.Mock() - protocol = asyncio.StreamReaderProtocol(reader) + async def test(): + return asyncio.StreamReaderProtocol(reader) + protocol = self.loop.run_until_complete(test()) + self.assertIs(protocol._loop, self.loop) + + 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 + 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.warnings[0].filename, __file__) self.assertIs(protocol._loop, self.loop) def test_drain_raises(self): diff --git a/Lib/test/test_asyncio/test_tasks.py b/Lib/test/test_asyncio/test_tasks.py index 7c2e85ceefd..a9e4cf53566 100644 --- a/Lib/test/test_asyncio/test_tasks.py +++ b/Lib/test/test_asyncio/test_tasks.py @@ -200,22 +200,76 @@ class BaseTaskTests: loop.close() def test_ensure_future_coroutine(self): + async def notmuch(): + return 'ok' + t = asyncio.ensure_future(notmuch(), loop=self.loop) + self.assertIs(t._loop, self.loop) + self.loop.run_until_complete(t) + self.assertTrue(t.done()) + self.assertEqual(t.result(), 'ok') + + 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.warnings[0].filename, __file__) + + async def test(): + return asyncio.ensure_future(notmuch()) + t = self.loop.run_until_complete(test()) + self.assertIs(t._loop, self.loop) + self.loop.run_until_complete(t) + self.assertTrue(t.done()) + self.assertEqual(t.result(), 'ok') + + # Deprecated in 3.10 + 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.warnings[0].filename, __file__) + self.assertIs(t._loop, self.loop) + self.loop.run_until_complete(t) + self.assertTrue(t.done()) + self.assertEqual(t.result(), 'ok') + + def test_ensure_future_coroutine_2(self): with self.assertWarns(DeprecationWarning): @asyncio.coroutine def notmuch(): return 'ok' t = asyncio.ensure_future(notmuch(), loop=self.loop) + self.assertIs(t._loop, self.loop) self.loop.run_until_complete(t) self.assertTrue(t.done()) self.assertEqual(t.result(), 'ok') - self.assertIs(t._loop, self.loop) - loop = asyncio.new_event_loop() - self.set_event_loop(loop) - t = asyncio.ensure_future(notmuch(), loop=loop) - self.assertIs(t._loop, loop) - loop.run_until_complete(t) - loop.close() + 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.warnings[0].filename, __file__) + + async def test(): + return asyncio.ensure_future(notmuch()) + t = self.loop.run_until_complete(test()) + self.assertIs(t._loop, self.loop) + self.loop.run_until_complete(t) + self.assertTrue(t.done()) + self.assertEqual(t.result(), 'ok') + + # Deprecated in 3.10 + 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.warnings[0].filename, __file__) + self.assertIs(t._loop, self.loop) + self.loop.run_until_complete(t) + self.assertTrue(t.done()) + self.assertEqual(t.result(), 'ok') def test_ensure_future_future(self): f_orig = self.new_future(self.loop) @@ -1078,33 +1132,6 @@ class BaseTaskTests: res = loop.run_until_complete(asyncio.wait_for(coro(), timeout=None)) self.assertEqual(res, 'done') - def test_wait_for_with_global_loop(self): - - def gen(): - when = yield - self.assertAlmostEqual(0.2, when) - when = yield 0 - self.assertAlmostEqual(0.01, when) - yield 0.01 - - loop = self.new_test_loop(gen) - - async def foo(): - await asyncio.sleep(0.2) - return 'done' - - asyncio.set_event_loop(loop) - try: - fut = self.new_task(loop, foo()) - with self.assertRaises(asyncio.TimeoutError): - loop.run_until_complete(asyncio.wait_for(fut, 0.01)) - finally: - asyncio.set_event_loop(None) - - self.assertAlmostEqual(0.01, loop.time()) - self.assertTrue(fut.done()) - self.assertTrue(fut.cancelled()) - def test_wait_for_race_condition(self): def gen(): @@ -1293,32 +1320,6 @@ class BaseTaskTests: self.assertAlmostEqual(0.15, loop.time()) self.assertEqual(res, 42) - def test_wait_with_global_loop(self): - - def gen(): - when = yield - self.assertAlmostEqual(0.01, when) - when = yield 0 - self.assertAlmostEqual(0.015, when) - yield 0.015 - - loop = self.new_test_loop(gen) - - a = self.new_task(loop, asyncio.sleep(0.01)) - b = self.new_task(loop, asyncio.sleep(0.015)) - - async def foo(): - done, pending = await asyncio.wait([b, a]) - self.assertEqual(done, set([a, b])) - self.assertEqual(pending, set()) - return 42 - - asyncio.set_event_loop(loop) - res = loop.run_until_complete( - self.new_task(loop, foo())) - - self.assertEqual(res, 42) - def test_wait_duplicate_coroutines(self): with self.assertWarns(DeprecationWarning): @@ -1679,22 +1680,24 @@ class BaseTaskTests: yield 0 loop = self.new_test_loop(gen) - asyncio.set_event_loop(loop) a = asyncio.sleep(0.05, 'a') b = asyncio.sleep(0.10, 'b') fs = {a, b} - futs = list(asyncio.as_completed(fs)) - self.assertEqual(len(futs), 2) + async def test(): + futs = list(asyncio.as_completed(fs)) + self.assertEqual(len(futs), 2) - x = loop.run_until_complete(futs[1]) - self.assertEqual(x, 'a') - self.assertAlmostEqual(0.05, loop.time()) - loop.advance_time(0.05) - y = loop.run_until_complete(futs[0]) - self.assertEqual(y, 'b') - self.assertAlmostEqual(0.10, loop.time()) + x = await futs[1] + self.assertEqual(x, 'a') + self.assertAlmostEqual(0.05, loop.time()) + loop.advance_time(0.05) + y = await futs[0] + self.assertEqual(y, 'b') + self.assertAlmostEqual(0.10, loop.time()) + + loop.run_until_complete(test()) def test_as_completed_concurrent(self): @@ -1705,20 +1708,22 @@ class BaseTaskTests: self.assertAlmostEqual(0.05, when) yield 0.05 - loop = self.new_test_loop(gen) - asyncio.set_event_loop(loop) - a = asyncio.sleep(0.05, 'a') b = asyncio.sleep(0.05, 'b') fs = {a, b} - futs = list(asyncio.as_completed(fs)) - self.assertEqual(len(futs), 2) - waiter = asyncio.wait(futs) - # Deprecation from passing coros in futs to asyncio.wait() - with self.assertWarns(DeprecationWarning): - done, pending = loop.run_until_complete(waiter) - self.assertEqual(set(f.result() for f in done), {'a', 'b'}) + async def test(): + futs = list(asyncio.as_completed(fs)) + self.assertEqual(len(futs), 2) + waiter = asyncio.wait(futs) + # Deprecation from passing coros in futs to asyncio.wait() + with self.assertWarns(DeprecationWarning) as cm: + done, pending = await waiter + self.assertEqual(cm.warnings[0].filename, __file__) + self.assertEqual(set(f.result() for f in done), {'a', 'b'}) + + loop = self.new_test_loop(gen) + loop.run_until_complete(test()) def test_as_completed_duplicate_coroutines(self): @@ -1742,6 +1747,47 @@ class BaseTaskTests: self.assertEqual(set(result), {'ham', 'spam'}) self.assertEqual(len(result), 2) + def test_as_completed_coroutine_without_loop(self): + async def coro(): + return 42 + + a = coro() + 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.warnings[0].filename, __file__) + + def test_as_completed_coroutine_use_running_loop(self): + loop = self.new_test_loop() + + async def coro(): + return 42 + + async def test(): + futs = list(asyncio.as_completed([coro()])) + self.assertEqual(len(futs), 1) + self.assertEqual(await futs[0], 42) + + loop.run_until_complete(test()) + + def test_as_completed_coroutine_use_global_loop(self): + # Deprecated in 3.10 + async def coro(): + return 42 + + loop = self.new_test_loop() + asyncio.set_event_loop(loop) + self.addCleanup(asyncio.set_event_loop, None) + futs = asyncio.as_completed([coro()]) + with self.assertWarns(DeprecationWarning) as cm: + futs = list(futs) + self.assertEqual(cm.warnings[0].filename, __file__) + self.assertEqual(len(futs), 1) + self.assertEqual(loop.run_until_complete(futs[0]), 42) + def test_sleep(self): def gen(): @@ -2201,6 +2247,42 @@ class BaseTaskTests: child2.set_result(2) test_utils.run_briefly(self.loop) + def test_shield_coroutine_without_loop(self): + async def coro(): + return 42 + + 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.warnings[0].filename, __file__) + + def test_shield_coroutine_use_running_loop(self): + async def coro(): + return 42 + + async def test(): + return asyncio.shield(coro()) + outer = self.loop.run_until_complete(test()) + self.assertEqual(outer._loop, self.loop) + res = self.loop.run_until_complete(outer) + self.assertEqual(res, 42) + + def test_shield_coroutine_use_global_loop(self): + # Deprecated in 3.10 + 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.warnings[0].filename, __file__) + self.assertEqual(outer._loop, self.loop) + res = self.loop.run_until_complete(outer) + self.assertEqual(res, 42) + def test_as_completed_invalid_args(self): fut = self.new_future(self.loop) @@ -2507,16 +2589,17 @@ class BaseTaskTests: """Ensure that a gathering future refuses to be cancelled once all children are done""" loop = asyncio.new_event_loop() - asyncio.set_event_loop(loop) self.addCleanup(loop.close) fut = self.new_future(loop) - # The indirection fut->child_coro is needed since otherwise the - # gathering task is done at the same time as the child future - def child_coro(): - return (yield from fut) - gather_future = asyncio.gather(child_coro()) - gather_task = asyncio.ensure_future(gather_future, loop=loop) + async def create(): + # The indirection fut->child_coro is needed since otherwise the + # gathering task is done at the same time as the child future + def child_coro(): + return (yield from fut) + gather_future = asyncio.gather(child_coro()) + return asyncio.ensure_future(gather_future) + gather_task = loop.run_until_complete(create()) cancel_result = None def cancelling_callback(_): @@ -3222,7 +3305,7 @@ class GatherTestsBase: def _check_success(self, **kwargs): a, b, c = [self.one_loop.create_future() for i in range(3)] - fut = asyncio.gather(*self.wrap_futures(a, b, c), **kwargs) + fut = self._gather(*self.wrap_futures(a, b, c), **kwargs) cb = test_utils.MockCallback() fut.add_done_callback(cb) b.set_result(1) @@ -3244,7 +3327,7 @@ class GatherTestsBase: def test_one_exception(self): a, b, c, d, e = [self.one_loop.create_future() for i in range(5)] - fut = asyncio.gather(*self.wrap_futures(a, b, c, d, e)) + fut = self._gather(*self.wrap_futures(a, b, c, d, e)) cb = test_utils.MockCallback() fut.add_done_callback(cb) exc = ZeroDivisionError() @@ -3262,8 +3345,8 @@ class GatherTestsBase: def test_return_exceptions(self): a, b, c, d = [self.one_loop.create_future() for i in range(4)] - fut = asyncio.gather(*self.wrap_futures(a, b, c, d), - return_exceptions=True) + fut = self._gather(*self.wrap_futures(a, b, c, d), + return_exceptions=True) cb = test_utils.MockCallback() fut.add_done_callback(cb) exc = ZeroDivisionError() @@ -3315,21 +3398,37 @@ class FutureGatherTests(GatherTestsBase, test_utils.TestCase): def wrap_futures(self, *futures): return futures - def _check_empty_sequence(self, seq_or_iter): - asyncio.set_event_loop(self.one_loop) - self.addCleanup(asyncio.set_event_loop, None) - fut = asyncio.gather(*seq_or_iter) + def _gather(self, *args, **kwargs): + 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.warnings[0].filename, __file__) + + def test_constructor_empty_sequence_use_running_loop(self): + async def gather(): + return asyncio.gather() + fut = self.one_loop.run_until_complete(gather()) self.assertIsInstance(fut, asyncio.Future) self.assertIs(fut._loop, self.one_loop) self._run_loop(self.one_loop) self.assertTrue(fut.done()) self.assertEqual(fut.result(), []) - def test_constructor_empty_sequence(self): - self._check_empty_sequence([]) - self._check_empty_sequence(()) - self._check_empty_sequence(set()) - self._check_empty_sequence(iter("")) + def test_constructor_empty_sequence_use_global_loop(self): + # Deprecated in 3.10 + 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.warnings[0].filename, __file__) + self.assertIsInstance(fut, asyncio.Future) + self.assertIs(fut._loop, self.one_loop) + self._run_loop(self.one_loop) + self.assertTrue(fut.done()) + self.assertEqual(fut.result(), []) def test_constructor_heterogenous_futures(self): fut1 = self.one_loop.create_future() @@ -3392,10 +3491,6 @@ class FutureGatherTests(GatherTestsBase, test_utils.TestCase): class CoroutineGatherTests(GatherTestsBase, test_utils.TestCase): - def setUp(self): - super().setUp() - asyncio.set_event_loop(self.one_loop) - def wrap_futures(self, *futures): coros = [] for fut in futures: @@ -3404,22 +3499,47 @@ class CoroutineGatherTests(GatherTestsBase, test_utils.TestCase): coros.append(coro()) return coros - def test_constructor_loop_selection(self): + def _gather(self, *args, **kwargs): + async def coro(): + return asyncio.gather(*args, **kwargs) + return self.one_loop.run_until_complete(coro()) + + def test_constructor_without_loop(self): + async def coro(): + return 'abc' + gen1 = coro() + 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.warnings[0].filename, __file__) + + def test_constructor_use_running_loop(self): async def coro(): return 'abc' gen1 = coro() gen2 = coro() - fut = asyncio.gather(gen1, gen2) + async def gather(): + return asyncio.gather(gen1, gen2) + fut = self.one_loop.run_until_complete(gather()) self.assertIs(fut._loop, self.one_loop) self.one_loop.run_until_complete(fut) - self.set_event_loop(self.other_loop, cleanup=False) + def test_constructor_use_global_loop(self): + # Deprecated in 3.10 + async def coro(): + return 'abc' asyncio.set_event_loop(self.other_loop) - gen3 = coro() - gen4 = coro() - fut2 = asyncio.gather(gen3, gen4) - self.assertIs(fut2._loop, self.other_loop) - self.other_loop.run_until_complete(fut2) + 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.warnings[0].filename, __file__) + self.assertIs(fut._loop, self.other_loop) + self.other_loop.run_until_complete(fut) def test_duplicate_coroutines(self): with self.assertWarns(DeprecationWarning): @@ -3427,7 +3547,7 @@ class CoroutineGatherTests(GatherTestsBase, test_utils.TestCase): def coro(s): return s c = coro('abc') - fut = asyncio.gather(c, c, coro('def'), c) + fut = self._gather(c, c, coro('def'), c) self._run_loop(self.one_loop) self.assertEqual(fut.result(), ['abc', 'abc', 'def', 'abc']) diff --git a/Misc/NEWS.d/next/Library/2020-12-06-20-21-16.bpo-39529.9Zrg43.rst b/Misc/NEWS.d/next/Library/2020-12-06-20-21-16.bpo-39529.9Zrg43.rst new file mode 100644 index 00000000000..bb1fd82c99e --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-12-06-20-21-16.bpo-39529.9Zrg43.rst @@ -0,0 +1,9 @@ +Deprecated use of :func:`asyncio.get_event_loop` without running event loop. +Emit deprecation warning for :mod:`asyncio` functions which implicitly +create a :class:`~asyncio.Future` or :class:`~asyncio.Task` objects if there +is no running event loop and no explicit *loop* argument is passed: +:func:`~asyncio.ensure_future`, :func:`~asyncio.wrap_future`, +:func:`~asyncio.gather`, :func:`~asyncio.shield`, +:func:`~asyncio.as_completed` and constructors of :class:`~asyncio.Future`, +:class:`~asyncio.Task`, :class:`~asyncio.StreamReader`, +:class:`~asyncio.StreamReaderProtocol`. diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c index 01e36c656da..a4d5d4551e9 100644 --- a/Modules/_asynciomodule.c +++ b/Modules/_asynciomodule.c @@ -319,7 +319,7 @@ set_running_loop(PyObject *loop) static PyObject * -get_event_loop(void) +get_event_loop(int stacklevel) { PyObject *loop; PyObject *policy; @@ -331,6 +331,13 @@ get_event_loop(void) 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; @@ -489,7 +496,7 @@ future_init(FutureObj *fut, PyObject *loop) fut->fut_blocking = 0; if (loop == Py_None) { - loop = get_event_loop(); + loop = get_event_loop(1); if (loop == NULL) { return -1; } @@ -3078,7 +3085,19 @@ static PyObject * _asyncio_get_event_loop_impl(PyObject *module) /*[clinic end generated code: output=2a2d8b2f824c648b input=9364bf2916c8655d]*/ { - return get_event_loop(); + return get_event_loop(1); +} + +/*[clinic input] +_asyncio._get_event_loop + stacklevel: int = 3 +[clinic start generated code]*/ + +static PyObject * +_asyncio__get_event_loop_impl(PyObject *module, int stacklevel) +/*[clinic end generated code: output=9c1d6d3c802e67c9 input=d17aebbd686f711d]*/ +{ + return get_event_loop(stacklevel-1); } /*[clinic input] @@ -3375,6 +3394,7 @@ PyDoc_STRVAR(module_doc, "Accelerator module for asyncio"); static PyMethodDef asyncio_methods[] = { _ASYNCIO_GET_EVENT_LOOP_METHODDEF + _ASYNCIO__GET_EVENT_LOOP_METHODDEF _ASYNCIO_GET_RUNNING_LOOP_METHODDEF _ASYNCIO__GET_RUNNING_LOOP_METHODDEF _ASYNCIO__SET_RUNNING_LOOP_METHODDEF diff --git a/Modules/clinic/_asynciomodule.c.h b/Modules/clinic/_asynciomodule.c.h index a071efc1e2b..c472e652fb7 100644 --- a/Modules/clinic/_asynciomodule.c.h +++ b/Modules/clinic/_asynciomodule.c.h @@ -669,6 +669,45 @@ _asyncio_get_event_loop(PyObject *module, PyObject *Py_UNUSED(ignored)) return _asyncio_get_event_loop_impl(module); } +PyDoc_STRVAR(_asyncio__get_event_loop__doc__, +"_get_event_loop($module, /, stacklevel=3)\n" +"--\n" +"\n"); + +#define _ASYNCIO__GET_EVENT_LOOP_METHODDEF \ + {"_get_event_loop", (PyCFunction)(void(*)(void))_asyncio__get_event_loop, METH_FASTCALL|METH_KEYWORDS, _asyncio__get_event_loop__doc__}, + +static PyObject * +_asyncio__get_event_loop_impl(PyObject *module, int stacklevel); + +static PyObject * +_asyncio__get_event_loop(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames) +{ + PyObject *return_value = NULL; + static const char * const _keywords[] = {"stacklevel", NULL}; + static _PyArg_Parser _parser = {NULL, _keywords, "_get_event_loop", 0}; + PyObject *argsbuf[1]; + Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 0; + int stacklevel = 3; + + args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 0, 1, 0, argsbuf); + if (!args) { + goto exit; + } + if (!noptargs) { + goto skip_optional_pos; + } + stacklevel = _PyLong_AsInt(args[0]); + if (stacklevel == -1 && PyErr_Occurred()) { + goto exit; + } +skip_optional_pos: + return_value = _asyncio__get_event_loop_impl(module, stacklevel); + +exit: + return return_value; +} + PyDoc_STRVAR(_asyncio_get_running_loop__doc__, "get_running_loop($module, /)\n" "--\n" @@ -832,4 +871,4 @@ _asyncio__leave_task(PyObject *module, PyObject *const *args, Py_ssize_t nargs, exit: return return_value; } -/*[clinic end generated code: output=d0fc522bcbff9d61 input=a9049054013a1b77]*/ +/*[clinic end generated code: output=0d127162ac92e0c0 input=a9049054013a1b77]*/