"""Tests for tasks.py."""
import collections
import contextlib
import contextvars
import gc
import io
import random
import re
import sys
import traceback
import types
import unittest
from unittest import mock
from types import GenericAlias
import asyncio
from asyncio import futures
from asyncio import tasks
from test.test_asyncio import utils as test_utils
from test import support
from test.support.script_helper import assert_python_ok
from test.support.warnings_helper import ignore_warnings
def tearDownModule():
asyncio.set_event_loop_policy(None)
async def coroutine_function():
pass
def format_coroutine(qualname, state, src, source_traceback, generator=False):
if generator:
state = '%s' % state
else:
state = '%s, defined' % state
if source_traceback is not None:
frame = source_traceback[-1]
return ('coro=<%s() %s at %s> created at %s:%s'
% (qualname, state, src, frame[0], frame[1]))
else:
return 'coro=<%s() %s at %s>' % (qualname, state, src)
def get_innermost_context(exc):
"""
Return information about the innermost exception context in the chain.
"""
depth = 0
while True:
context = exc.__context__
if context is None:
break
exc = context
depth += 1
return (type(exc), exc.args, depth)
class Dummy:
def __repr__(self):
return '<Dummy>'
def __call__(self, *args):
pass
class CoroLikeObject:
def send(self, v):
raise StopIteration(42)
def throw(self, *exc):
pass
def close(self):
pass
def __await__(self):
return self
class BaseTaskTests:
Task = None
Future = None
all_tasks = None
def new_task(self, loop, coro, name='TestTask', context=None):
return self.__class__.Task(coro, loop=loop, name=name, context=context)
def new_future(self, loop):
return self.__class__.Future(loop=loop)
def setUp(self):
super().setUp()
self.loop = self.new_test_loop()
self.loop.set_task_factory(self.new_task)
self.loop.create_future = lambda: self.new_future(self.loop)
def test_generic_alias(self):
task = self.__class__.Task[str]
self.assertEqual(task.__args__, (str,))
self.assertIsInstance(task, GenericAlias)
def test_task_cancel_message_getter(self):
async def coro():
pass
t = self.new_task(self.loop, coro())
self.assertTrue(hasattr(t, '_cancel_message'))
self.assertEqual(t._cancel_message, None)
t.cancel('my message')
self.assertEqual(t._cancel_message, 'my message')
with self.assertRaises(asyncio.CancelledError) as cm:
self.loop.run_until_complete(t)
self.assertEqual('my message', cm.exception.args[0])
def test_task_cancel_message_setter(self):
async def coro():
pass
t = self.new_task(self.loop, coro())
t.cancel('my message')
t._cancel_message = 'my new message'
self.assertEqual(t._cancel_message, 'my new message')
with self.assertRaises(asyncio.CancelledError) as cm:
self.loop.run_until_complete(t)
self.assertEqual('my new message', cm.exception.args[0])
def test_task_del_collect(self):
class Evil:
def __del__(self):
gc.collect()
async def run():
return Evil()
self.loop.run_until_complete(
asyncio.gather(*[
self.new_task(self.loop, run()) for _ in range(100)
]))
def test_other_loop_future(self):
other_loop = asyncio.new_event_loop()
fut = self.new_future(other_loop)
async def run(fut):
await fut
try:
with self.assertRaisesRegex(RuntimeError,
r'Task .* got Future .* attached'):
self.loop.run_until_complete(run(fut))
finally:
other_loop.close()
def test_task_awaits_on_itself(self):
async def test():
await task
task = asyncio.ensure_future(test(), loop=self.loop)
with self.assertRaisesRegex(RuntimeError,
'Task cannot await on itself'):
self.loop.run_until_complete(task)
def test_task_class(self):
async def notmuch():
return 'ok'
t = self.new_task(self.loop, notmuch())
self.loop.run_until_complete(t)
self.assertTrue(t.done())
self.assertEqual(t.result(), 'ok')
self.assertIs(t._loop, self.loop)
self.assertIs(t.get_loop(), self.loop)
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
t = self.new_task(loop, notmuch())
self.assertIs(t._loop, loop)
loop.run_until_complete(t)
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.assertRaisesRegex(RuntimeError, 'no current event loop'):
asyncio.ensure_future(a)
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, undeprecated in 3.12
asyncio.set_event_loop(self.loop)
self.addCleanup(asyncio.set_event_loop, None)
t = asyncio.ensure_future(notmuch())
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)
f_orig.set_result('ko')
f = asyncio.ensure_future(f_orig)
self.loop.run_until_complete(f)
self.assertTrue(f.done())
self.assertEqual(f.result(), 'ko')
self.assertIs(f, f_orig)
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
with self.assertRaises(ValueError):
f = asyncio.ensure_future(f_orig, loop=loop)
loop.close()
f = asyncio.ensure_future(f_orig, loop=self.loop)
self.assertIs(f, f_orig)
def test_ensure_future_task(self):
async def notmuch():
return 'ok'
t_orig = self.new_task(self.loop, notmuch())
t = asyncio.ensure_future(t_orig)
self.loop.run_until_complete(t)
self.assertTrue(t.done())
self.assertEqual(t.result(), 'ok')
self.assertIs(t, t_orig)
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
with self.assertRaises(ValueError):
t = asyncio.ensure_future(t_orig, loop=loop)
loop.close()
t = asyncio.ensure_future(t_orig, loop=self.loop)
self.assertIs(t, t_orig)
def test_ensure_future_awaitable(self):
class Aw:
def __init__(self, coro):
self.coro = coro
def __await__(self):
return self.coro.__await__()
async def coro():
return 'ok'
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
fut = asyncio.ensure_future(Aw(coro()), loop=loop)
loop.run_until_complete(fut)
self.assertEqual(fut.result(), 'ok')
def test_ensure_future_task_awaitable(self):
class Aw:
def __await__(self):
return asyncio.sleep(0, result='ok').__await__()
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
task = asyncio.ensure_future(Aw(), loop=loop)
loop.run_until_complete(task)
self.assertTrue(task.done())
self.assertEqual(task.result(), 'ok')
self.assertIsInstance(task.get_coro(), types.CoroutineType)
loop.close()
def test_ensure_future_neither(self):
with self.assertRaises(TypeError):
asyncio.ensure_future('ok')
def test_ensure_future_error_msg(self):
loop = asyncio.new_event_loop()
f = self.new_future(self.loop)
with self.assertRaisesRegex(ValueError, 'The future belongs to a '
'different loop than the one specified as '
'the loop argument'):
asyncio.ensure_future(f, loop=loop)
loop.close()
def test_get_stack(self):
T = None
async def foo():
await bar()
async def bar():
# test get_stack()
f = T.get_stack(limit=1)
try:
self.assertEqual(f[0].f_code.co_name, 'foo')
finally:
f = None
# test print_stack()
file = io.StringIO()
T.print_stack(limit=1, file=file)
file.seek(0)
tb = file.read()
self.assertRegex(tb, r'foo\(\) running')
async def runner():
nonlocal T
T = asyncio.ensure_future(foo(), loop=self.loop)
await T
self.loop.run_until_complete(runner())
def test_task_repr(self):
self.loop.set_debug(False)
async def notmuch():
return 'abc'
# test coroutine function
self.assertEqual(notmuch.__name__, 'notmuch')
self.assertRegex(notmuch.__qualname__,
r'\w+.test_task_repr.<locals>.notmuch')
self.assertEqual(notmuch.__module__, __name__)
filename, lineno = test_utils.get_function_source(notmuch)
src = "%s:%s" % (filename, lineno)
# test coroutine object
gen = notmuch()
coro_qualname = 'BaseTaskTests.test_task_repr.<locals>.notmuch'
self.assertEqual(gen.__name__, 'notmuch')
self.assertEqual(gen.__qualname__, coro_qualname)
# test pending Task
t = self.new_task(self.loop, gen)
t.add_done_callback(Dummy())
coro = format_coroutine(coro_qualname, 'running', src,
t._source_traceback, generator=True)
self.assertEqual(repr(t),
"<Task pending name='TestTask' %s cb=[<Dummy>()]>" % coro)
# test cancelling Task
t.cancel() # Does not take immediate effect!
self.assertEqual(repr(t),
"<Task cancelling name='TestTask' %s cb=[<Dummy>()]>" % coro)
# test cancelled Task
self.assertRaises(asyncio.CancelledError,
self.loop.run_until_complete, t)
coro = format_coroutine(coro_qualname, 'done', src,
t._source_traceback)
self.assertEqual(repr(t),
"<Task cancelled name='TestTask' %s>" % coro)
# test finished Task
t = self.new_task(self.loop, notmuch())
self.loop.run_until_complete(t)
coro = format_coroutine(coro_qualname, 'done', src,
t._source_traceback)
self.assertEqual(repr(t),
"<Task finished name='TestTask' %s result='abc'>" % coro)
def test_task_repr_autogenerated(self):
async def notmuch():
return 123
t1 = self.new_task(self.loop, notmuch(), None)
t2 = self.new_task(self.loop, notmuch(), None)
self.assertNotEqual(repr(t1), repr(t2))
match1 = re.match(r"^<Task pending name='Task-(\d+)'", repr(t1))
self.assertIsNotNone(match1)
match2 = re.match(r"^<Task pending name='Task-(\d+)'", repr(t2))
self.assertIsNotNone(match2)
# Autogenerated task names should have monotonically increasing numbers
self.assertLess(int(match1.group(1)), int(match2.group(1)))
self.loop.run_until_complete(t1)
self.loop.run_until_complete(t2)
def test_task_set_name_pylong(self):
# test that setting the task name to a PyLong explicitly doesn't
# incorrectly trigger the deferred name formatting logic
async def notmuch():
return 123
t = self.new_task(self.loop, notmuch(), name=987654321)
self.assertEqual(t.get_name(), '987654321')
t.set_name(123456789)
self.assertEqual(t.get_name(), '123456789')
self.loop.run_until_complete(t)
def test_task_repr_name_not_str(self):
async def notmuch():
return 123
t = self.new_task(self.loop, notmuch())
t.set_name({6})
self.assertEqual(t.get_name(), '{6}')
self.loop.run_until_complete(t)
def test_task_repr_wait_for(self):
self.loop.set_debug(False)
async def wait_for(fut):
return await fut
fut = self.new_future(self.loop)
task = self.new_task(self.loop, wait_for(fut))
test_utils.run_briefly(self.loop)
self.assertRegex(repr(task),
'<Task .* wait_for=%s>' % re.escape(repr(fut)))
fut.set_result(None)
self.loop.run_until_complete(task)
def test_task_basics(self):
async def outer():
a = await inner1()
b = await inner2()
return a+b
async def inner1():
return 42
async def inner2():
return 1000
t = outer()
self.assertEqual(self.loop.run_until_complete(t), 1042)
def test_exception_chaining_after_await(self):
# Test that when awaiting on a task when an exception is already
# active, if the task raises an exception it will be chained
# with the original.
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def raise_error():
raise ValueError
async def run():
try:
raise KeyError(3)
except Exception as exc:
task = self.new_task(loop, raise_error())
try:
await task
except Exception as exc:
self.assertEqual(type(exc), ValueError)
chained = exc.__context__
self.assertEqual((type(chained), chained.args),
(KeyError, (3,)))
try:
task = self.new_task(loop, run())
loop.run_until_complete(task)
finally:
loop.close()
def test_exception_chaining_after_await_with_context_cycle(self):
# Check trying to create an exception context cycle:
# https://bugs.python.org/issue40696
has_cycle = None
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def process_exc(exc):
raise exc
async def run():
nonlocal has_cycle
try:
raise KeyError('a')
except Exception as exc:
task = self.new_task(loop, process_exc(exc))
try:
await task
except BaseException as exc:
has_cycle = (exc is exc.__context__)
# Prevent a hang if has_cycle is True.
exc.__context__ = None
try:
task = self.new_task(loop, run())
loop.run_until_complete(task)
finally:
loop.close()
# This also distinguishes from the initial has_cycle=None.
self.assertEqual(has_cycle, False)
def test_cancelling(self):
loop = asyncio.new_event_loop()
async def task():
await asyncio.sleep(10)
try:
t = self.new_task(loop, task())
self.assertFalse(t.cancelling())
self.assertNotIn(" cancelling ", repr(t))
self.assertTrue(t.cancel())
self.assertTrue(t.cancelling())
self.assertIn(" cancelling ", repr(t))
# Since we commented out two lines from Task.cancel(),
# this t.cancel() call now returns True.
# self.assertFalse(t.cancel())
self.assertTrue(t.cancel())
with self.assertRaises(asyncio.CancelledError):
loop.run_until_complete(t)
finally:
loop.close()
def test_uncancel_basic(self):
loop = asyncio.new_event_loop()
async def task():
try:
await asyncio.sleep(10)
except asyncio.CancelledError:
asyncio.current_task().uncancel()
await asyncio.sleep(10)
try:
t = self.new_task(loop, task())
loop.run_until_complete(asyncio.sleep(0.01))
# Cancel first sleep
self.assertTrue(t.cancel())
self.assertIn(" cancelling ", repr(t))
self.assertEqual(t.cancelling(), 1)
self.assertFalse(t.cancelled()) # Task is still not complete
loop.run_until_complete(asyncio.sleep(0.01))
# after .uncancel()
self.assertNotIn(" cancelling ", repr(t))
self.assertEqual(t.cancelling(), 0)
self.assertFalse(t.cancelled()) # Task is still not complete
# Cancel second sleep
self.assertTrue(t.cancel())
self.assertEqual(t.cancelling(), 1)
self.assertFalse(t.cancelled()) # Task is still not complete
with self.assertRaises(asyncio.CancelledError):
loop.run_until_complete(t)
self.assertTrue(t.cancelled()) # Finally, task complete
self.assertTrue(t.done())
# uncancel is no longer effective after the task is complete
t.uncancel()
self.assertTrue(t.cancelled())
self.assertTrue(t.done())
finally:
loop.close()
def test_uncancel_structured_blocks(self):
# This test recreates the following high-level structure using uncancel()::
#
# async def make_request_with_timeout():
# try:
# async with asyncio.timeout(1):
# # Structured block affected by the timeout:
# await make_request()
# await make_another_request()
# except TimeoutError:
# pass # There was a timeout
# # Outer code not affected by the timeout:
# await unrelated_code()
loop = asyncio.new_event_loop()
async def make_request_with_timeout(*, sleep: float, timeout: float):
task = asyncio.current_task()
loop = task.get_loop()
timed_out = False
structured_block_finished = False
outer_code_reached = False
def on_timeout():
nonlocal timed_out
timed_out = True
task.cancel()
timeout_handle = loop.call_later(timeout, on_timeout)
try:
try:
# Structured block affected by the timeout
await asyncio.sleep(sleep)
structured_block_finished = True
finally:
timeout_handle.cancel()
if (
timed_out
and task.uncancel() == 0
and type(sys.exception()) is asyncio.CancelledError
):
# Note the five rules that are needed here to satisfy proper
# uncancellation:
#
# 1. handle uncancellation in a `finally:` block to allow for
# plain returns;
# 2. our `timed_out` flag is set, meaning that it was our event
# that triggered the need to uncancel the task, regardless of
# what exception is raised;
# 3. we can call `uncancel()` because *we* called `cancel()`
# before;
# 4. we call `uncancel()` but we only continue converting the
# CancelledError to TimeoutError if `uncancel()` caused the
# cancellation request count go down to 0. We need to look
# at the counter vs having a simple boolean flag because our
# code might have been nested (think multiple timeouts). See
# commit 7fce1063b6e5a366f8504e039a8ccdd6944625cd for
# details.
# 5. we only convert CancelledError to TimeoutError; for other
# exceptions raised due to the cancellation (like
# a ConnectionLostError from a database client), simply
# propagate them.
#
# Those checks need to take place in this exact order to make
# sure the `cancelling()` counter always stays in sync.
#
# Additionally, the original stimulus to `cancel()` the task
# needs to be unscheduled to avoid re-cancelling the task later.
# Here we do it by cancelling `timeout_handle` in the `finally:`
# block.
raise TimeoutError
except TimeoutError:
self.assertTrue(timed_out)
# Outer code not affected by the timeout:
outer_code_reached = True
await asyncio.sleep(0)
return timed_out, structured_block_finished, outer_code_reached
try:
# Test which timed out.
t1 = self.new_task(loop, make_request_with_timeout(sleep=10.0, timeout=0.1))
timed_out, structured_block_finished, outer_code_reached = (
loop.run_until_complete(t1)
)
self.assertTrue(timed_out)
self.assertFalse(structured_block_finished) # it was cancelled
self.assertTrue(outer_code_reached) # task got uncancelled after leaving
# the structured block and continued until
# completion
self.assertEqual(t1.cancelling(), 0) # no pending cancellation of the outer task
# Test which did not time out.
t2 = self.new_task(loop, make_request_with_timeout(sleep=0, timeout=10.0))
timed_out, structured_block_finished, outer_code_reached = (
loop.run_until_complete(t2)
)
self.assertFalse(timed_out)
self.assertTrue(structured_block_finished)
self.assertTrue(outer_code_reached)
self.assertEqual(t2.cancelling(), 0)
finally:
loop.close()
def test_uncancel_resets_must_cancel(self):
async def coro():
await fut
return 42
loop = asyncio.new_event_loop()
fut = asyncio.Future(loop=loop)
task = self.new_task(loop, coro())
loop.run_until_complete(asyncio.sleep(0)) # Get task waiting for fut
fut.set_result(None) # Make task runnable
try:
task.cancel() # Enter cancelled state
self.assertEqual(task.cancelling(), 1)
self.assertTrue(task._must_cancel)
task.uncancel() # Undo cancellation
self.assertEqual(task.cancelling(), 0)
self.assertFalse(task._must_cancel)
finally:
res = loop.run_until_complete(task)
self.assertEqual(res, 42)
loop.close()
def test_cancel(self):
def gen():
when = yield
self.assertAlmostEqual(10.0, when)
yield 0
loop = self.new_test_loop(gen)
async def task():
await asyncio.sleep(10.0)
return 12
t = self.new_task(loop, task())
loop.call_soon(t.cancel)
with self.assertRaises(asyncio.CancelledError):
loop.run_until_complete(t)
self.assertTrue(t.done())
self.assertTrue(t.cancelled())
self.assertFalse(t.cancel())
def test_cancel_with_message_then_future_result(self):
# Test Future.result() after calling cancel() with a message.
cases = [
((), ()),
((None,), ()),
(('my message',), ('my message',)),
# Non-string values should roundtrip.
((5,), (5,)),
]
for cancel_args, expected_args in cases:
with self.subTest(cancel_args=cancel_args):
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def sleep():
await asyncio.sleep(10)
async def coro():
task = self.new_task(loop, sleep())
await asyncio.sleep(0)
task.cancel(*cancel_args)
done, pending = await asyncio.wait([task])
task.result()
task = self.new_task(loop, coro())
with self.assertRaises(asyncio.CancelledError) as cm:
loop.run_until_complete(task)
exc = cm.exception
self.assertEqual(exc.args, expected_args)
actual = get_innermost_context(exc)
self.assertEqual(actual,
(asyncio.CancelledError, expected_args, 0))
def test_cancel_with_message_then_future_exception(self):
# Test Future.exception() after calling cancel() with a message.
cases = [
((), ()),
((None,), ()),
(('my message',), ('my message',)),
# Non-string values should roundtrip.
((5,), (5,)),
]
for cancel_args, expected_args in cases:
with self.subTest(cancel_args=cancel_args):
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def sleep():
await asyncio.sleep(10)
async def coro():
task = self.new_task(loop, sleep())
await asyncio.sleep(0)
task.cancel(*cancel_args)
done, pending = await asyncio.wait([task])
task.exception()
task = self.new_task(loop, coro())
with self.assertRaises(asyncio.CancelledError) as cm:
loop.run_until_complete(task)
exc = cm.exception
self.assertEqual(exc.args, expected_args)
actual = get_innermost_context(exc)
self.assertEqual(actual,
(asyncio.CancelledError, expected_args, 0))
def test_cancellation_exception_context(self):
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
fut = loop.create_future()
async def sleep():
fut.set_result(None)
await asyncio.sleep(10)
async def coro():
inner_task = self.new_task(loop, sleep())
await fut
loop.call_soon(inner_task.cancel, 'msg')
try:
await inner_task
except asyncio.CancelledError as ex:
raise ValueError("cancelled") from ex
task = self.new_task(loop, coro())
with self.assertRaises(ValueError) as cm:
loop.run_until_complete(task)
exc = cm.exception
self.assertEqual(exc.args, ('cancelled',))
actual = get_innermost_context(exc)
self.assertEqual(actual,
(asyncio.CancelledError, ('msg',), 1))
def test_cancel_with_message_before_starting_task(self):
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def sleep():
await asyncio.sleep(10)
async def coro():
task = self.new_task(loop, sleep())
# We deliberately leave out the sleep here.
task.cancel('my message')
done, pending = await asyncio.wait([task])
task.exception()
task = self.new_task(loop, coro())
with self.assertRaises(asyncio.CancelledError) as cm:
loop.run_until_complete(task)
exc = cm.exception
self.assertEqual(exc.args, ('my message',))
actual = get_innermost_context(exc)
self.assertEqual(actual,
(asyncio.CancelledError, ('my message',), 0))
def test_cancel_yield(self):
async def task():
await asyncio.sleep(0)
await asyncio.sleep(0)
return 12
t = self.new_task(self.loop, task())
test_utils.run_briefly(self.loop) # start coro
t.cancel()
self.assertRaises(
asyncio.CancelledError, self.loop.run_until_complete, t)
self.assertTrue(t.done())
self.assertTrue(t.cancelled())
self.assertFalse(t.cancel())
def test_cancel_inner_future(self):
f = self.new_future(self.loop)
async def task():
await f
return 12
t = self.new_task(self.loop, task())
test_utils.run_briefly(self.loop) # start task
f.cancel()
with self.assertRaises(asyncio.CancelledError):
self.loop.run_until_complete(t)
self.assertTrue(f.cancelled())
self.assertTrue(t.cancelled())
def test_cancel_both_task_and_inner_future(self):
f = self.new_future(self.loop)
async def task():
await f
return 12
t = self.new_task(self.loop, task())
test_utils.run_briefly(self.loop)
f.cancel()
t.cancel()
with self.assertRaises(asyncio.CancelledError):
self.loop.run_until_complete(t)
self.assertTrue(t.done())
self.assertTrue(f.cancelled())
self.assertTrue(t.cancelled())
def test_cancel_task_catching(self):
fut1 = self.new_future(self.loop)
fut2 = self.new_future(self.loop)
async def task():
await fut1
try:
await fut2
except asyncio.CancelledError:
return 42
t = self.new_task(self.loop, task())
test_utils.run_briefly(self.loop)
self.assertIs(t._fut_waiter, fut1) # White-box test.
fut1.set_result(None)
test_utils.run_briefly(self.loop)
self.assertIs(t._fut_waiter, fut2) # White-box test.
t.cancel()
self.assertTrue(fut2.cancelled())
res = self.loop.run_until_complete(t)
self.assertEqual(res, 42)
self.assertFalse(t.cancelled())
def test_cancel_task_ignoring(self):
fut1 = self.new_future(self.loop)
fut2 = self.new_future(self.loop)
fut3 = self.new_future(self.loop)
async def task():
await fut1
try:
await fut2
except asyncio.CancelledError:
pass
res = await fut3
return res
t = self.new_task(self.loop, task())
test_utils.run_briefly(self.loop)
self.assertIs(t._fut_waiter, fut1) # White-box test.
fut1.set_result(None)
test_utils.run_briefly(self.loop)
self.assertIs(t._fut_waiter, fut2) # White-box test.
t.cancel()
self.assertTrue(fut2.cancelled())
test_utils.run_briefly(self.loop)
self.assertIs(t._fut_waiter, fut3) # White-box test.
fut3.set_result(42)
res = self.loop.run_until_complete(t)
self.assertEqual(res, 42)
self.assertFalse(fut3.cancelled())
self.assertFalse(t.cancelled())
def test_cancel_current_task(self):
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def task():
t.cancel()
self.assertTrue(t._must_cancel) # White-box test.
# The sleep should be cancelled immediately.
await asyncio.sleep(100)
return 12
t = self.new_task(loop, task())
self.assertFalse(t.cancelled())
self.assertRaises(
asyncio.CancelledError, loop.run_until_complete, t)
self.assertTrue(t.done())
self.assertTrue(t.cancelled())
self.assertFalse(t._must_cancel) # White-box test.
self.assertFalse(t.cancel())
def test_cancel_at_end(self):
"""coroutine end right after task is cancelled"""
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def task():
t.cancel()
self.assertTrue(t._must_cancel) # White-box test.
return 12
t = self.new_task(loop, task())
self.assertFalse(t.cancelled())
self.assertRaises(
asyncio.CancelledError, loop.run_until_complete, t)
self.assertTrue(t.done())
self.assertTrue(t.cancelled())
self.assertFalse(t._must_cancel) # White-box test.
self.assertFalse(t.cancel())
def test_cancel_awaited_task(self):
# This tests for a relatively rare condition when
# a task cancellation is requested for a task which is not
# currently blocked, such as a task cancelling itself.
# In this situation we must ensure that whatever next future
# or task the cancelled task blocks on is cancelled correctly
# as well. See also bpo-34872.
loop = asyncio.new_event_loop()
self.addCleanup(lambda: loop.close())
task = nested_task = None
fut = self.new_future(loop)
async def nested():
await fut
async def coro():
nonlocal nested_task
# Create a sub-task and wait for it to run.
nested_task = self.new_task(loop, nested())
await asyncio.sleep(0)
# Request the current task to be cancelled.
task.cancel()
# Block on the nested task, which should be immediately
# cancelled.
await nested_task
task = self.new_task(loop, coro())
with self.assertRaises(asyncio.CancelledError):
loop.run_until_complete(task)
self.assertTrue(task.cancelled())
self.assertTrue(nested_task.cancelled())
self.assertTrue(fut.cancelled())
def assert_text_contains(self, text, substr):
if substr not in text:
raise RuntimeError(f'text {substr!r} not found in:\n>>>{text}<<<')
def test_cancel_traceback_for_future_result(self):
# When calling Future.result() on a cancelled task, check that the
# line of code that was interrupted is included in the traceback.
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def nested():
# This will get cancelled immediately.
await asyncio.sleep(10)
async def coro():
task = self.new_task(loop, nested())
await asyncio.sleep(0)
task.cancel()
await task # search target
task = self.new_task(loop, coro())
try:
loop.run_until_complete(task)
except asyncio.CancelledError:
tb = traceback.format_exc()
self.assert_text_contains(tb, "await asyncio.sleep(10)")
# The intermediate await should also be included.
self.assert_text_contains(tb, "await task # search target")
else:
self.fail('CancelledError did not occur')
def test_cancel_traceback_for_future_exception(self):
# When calling Future.exception() on a cancelled task, check that the
# line of code that was interrupted is included in the traceback.
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def nested():
# This will get cancelled immediately.
await asyncio.sleep(10)
async def coro():
task = self.new_task(loop, nested())
await asyncio.sleep(0)
task.cancel()
done, pending = await asyncio.wait([task])
task.exception() # search target
task = self.new_task(loop, coro())
try:
loop.run_until_complete(task)
except asyncio.CancelledError:
tb = traceback.format_exc()
self.assert_text_contains(tb, "await asyncio.sleep(10)")
# The intermediate await should also be included.
self.assert_text_contains(tb,
"task.exception() # search target")
else:
self.fail('CancelledError did not occur')
def test_stop_while_run_in_complete(self):
def gen():
when = yield
self.assertAlmostEqual(0.1, when)
when = yield 0.1
self.assertAlmostEqual(0.2, when)
when = yield 0.1
self.assertAlmostEqual(0.3, when)
yield 0.1
loop = self.new_test_loop(gen)
x = 0
async def task():
nonlocal x
while x < 10:
await asyncio.sleep(0.1)
x += 1
if x == 2:
loop.stop()
t = self.new_task(loop, task())
with self.assertRaises(RuntimeError) as cm:
loop.run_until_complete(t)
self.assertEqual(str(cm.exception),
'Event loop stopped before Future completed.')
self.assertFalse(t.done())
self.assertEqual(x, 2)
self.assertAlmostEqual(0.3, loop.time())
t.cancel()
self.assertRaises(asyncio.CancelledError, loop.run_until_complete, t)
def test_log_traceback(self):
async def coro():
pass
task = self.new_task(self.loop, coro())
with self.assertRaisesRegex(ValueError, 'can only be set to False'):
task._log_traceback = True
self.loop.run_until_complete(task)
def test_wait(self):
def gen():
when = yield
self.assertAlmostEqual(0.1, when)
when = yield 0
self.assertAlmostEqual(0.15, when)
yield 0.15
loop = self.new_test_loop(gen)
a = self.new_task(loop, asyncio.sleep(0.1))
b = self.new_task(loop, asyncio.sleep(0.15))
async def foo():
done, pending = await asyncio.wait([b, a])
self.assertEqual(done, set([a, b]))
self.assertEqual(pending, set())
return 42
res = loop.run_until_complete(self.new_task(loop, foo()))
self.assertEqual(res, 42)
self.assertAlmostEqual(0.15, loop.time())
# Doing it again should take no time and exercise a different path.
res = loop.run_until_complete(self.new_task(loop, foo()))
self.assertAlmostEqual(0.15, loop.time())
self.assertEqual(res, 42)
def test_wait_duplicate_coroutines(self):
async def coro(s):
return s
c = self.loop.create_task(coro('test'))
task = self.new_task(
self.loop,
asyncio.wait([c, c, self.loop.create_task(coro('spam'))]))
done, pending = self.loop.run_until_complete(task)
self.assertFalse(pending)
self.assertEqual(set(f.result() for f in done), {'test', 'spam'})
def test_wait_errors(self):
self.assertRaises(
ValueError, self.loop.run_until_complete,
asyncio.wait(set()))
# -1 is an invalid return_when value
sleep_coro = asyncio.sleep(10.0)
wait_coro = asyncio.wait([sleep_coro], return_when=-1)
self.assertRaises(ValueError,
self.loop.run_until_complete, wait_coro)
sleep_coro.close()
def test_wait_first_completed(self):
def gen():
when = yield
self.assertAlmostEqual(10.0, when)
when = yield 0
self.assertAlmostEqual(0.1, when)
yield 0.1
loop = self.new_test_loop(gen)
a = self.new_task(loop, asyncio.sleep(10.0))
b = self.new_task(loop, asyncio.sleep(0.1))
task = self.new_task(
loop,
asyncio.wait([b, a], return_when=asyncio.FIRST_COMPLETED))
done, pending = loop.run_until_complete(task)
self.assertEqual({b}, done)
self.assertEqual({a}, pending)
self.assertFalse(a.done())
self.assertTrue(b.done())
self.assertIsNone(b.result())
self.assertAlmostEqual(0.1, loop.time())
# move forward to close generator
loop.advance_time(10)
loop.run_until_complete(asyncio.wait([a, b]))
def test_wait_really_done(self):
# there is possibility that some tasks in the pending list
# became done but their callbacks haven't all been called yet
async def coro1():
await asyncio.sleep(0)
async def coro2():
await asyncio.sleep(0)
await asyncio.sleep(0)
a = self.new_task(self.loop, coro1())
b = self.new_task(self.loop, coro2())
task = self.new_task(
self.loop,
asyncio.wait([b, a], return_when=asyncio.FIRST_COMPLETED))
done, pending = self.loop.run_until_complete(task)
self.assertEqual({a, b}, done)
self.assertTrue(a.done())
self.assertIsNone(a.result())
self.assertTrue(b.done())
self.assertIsNone(b.result())
def test_wait_first_exception(self):
def gen():
when = yield
self.assertAlmostEqual(10.0, when)
yield 0
loop = self.new_test_loop(gen)
# first_exception, task already has exception
a = self.new_task(loop, asyncio.sleep(10.0))
async def exc():
raise ZeroDivisionError('err')
b = self.new_task(loop, exc())
task = self.new_task(
loop,
asyncio.wait([b, a], return_when=asyncio.FIRST_EXCEPTION))
done, pending = loop.run_until_complete(task)
self.assertEqual({b}, done)
self.assertEqual({a}, pending)
self.assertAlmostEqual(0, loop.time())
# move forward to close generator
loop.advance_time(10)
loop.run_until_complete(asyncio.wait([a, b]))
def test_wait_first_exception_in_wait(self):
def gen():
when = yield
self.assertAlmostEqual(10.0, when)
when = yield 0
self.assertAlmostEqual(0.01, when)
yield 0.01
loop = self.new_test_loop(gen)
# first_exception, exception during waiting
a = self.new_task(loop, asyncio.sleep(10.0))
async def exc():
await asyncio.sleep(0.01)
raise ZeroDivisionError('err')
b = self.new_task(loop, exc())
task = asyncio.wait([b, a], return_when=asyncio.FIRST_EXCEPTION)
done, pending = loop.run_until_complete(task)
self.assertEqual({b}, done)
self.assertEqual({a}, pending)
self.assertAlmostEqual(0.01, loop.time())
# move forward to close generator
loop.advance_time(10)
loop.run_until_complete(asyncio.wait([a, b]))
def test_wait_with_exception(self):
def gen():
when = yield
self.assertAlmostEqual(0.1, when)
when = yield 0
self.assertAlmostEqual(0.15, when)
yield 0.15
loop = self.new_test_loop(gen)
a = self.new_task(loop, asyncio.sleep(0.1))
async def sleeper():
await asyncio.sleep(0.15)
raise ZeroDivisionError('really')
b = self.new_task(loop, sleeper())
async def foo():
done, pending = await asyncio.wait([b, a])
self.assertEqual(len(done), 2)
self.assertEqual(pending, set())
errors = set(f for f in done if f.exception() is not None)
self.assertEqual(len(errors), 1)
loop.run_until_complete(self.new_task(loop, foo()))
self.assertAlmostEqual(0.15, loop.time())
loop.run_until_complete(self.new_task(loop, foo()))
self.assertAlmostEqual(0.15, loop.time())
def test_wait_with_timeout(self):
def gen():
when = yield
self.assertAlmostEqual(0.1, when)
when = yield 0
self.assertAlmostEqual(0.15, when)
when = yield 0
self.assertAlmostEqual(0.11, when)
yield 0.11
loop = self.new_test_loop(gen)
a = self.new_task(loop, asyncio.sleep(0.1))
b = self.new_task(loop, asyncio.sleep(0.15))
async def foo():
done, pending = await asyncio.wait([b, a], timeout=0.11)
self.assertEqual(done, set([a]))
self.assertEqual(pending, set([b]))
loop.run_until_complete(self.new_task(loop, foo()))
self.assertAlmostEqual(0.11, loop.time())
# move forward to close generator
loop.advance_time(10)
loop.run_until_complete(asyncio.wait([a, b]))
def test_wait_concurrent_complete(self):
def gen():
when = yield
self.assertAlmostEqual(0.1, when)
when = yield 0
self.assertAlmostEqual(0.15, when)
when = yield 0
self.assertAlmostEqual(0.1, when)
yield 0.1
loop = self.new_test_loop(gen)
a = self.new_task(loop, asyncio.sleep(0.1))
b = self.new_task(loop, asyncio.sleep(0.15))
done, pending = loop.run_until_complete(
asyncio.wait([b, a], timeout=0.1))
self.assertEqual(done, set([a]))
self.assertEqual(pending, set([b]))
self.assertAlmostEqual(0.1, loop.time())
# move forward to close generator
loop.advance_time(10)
loop.run_until_complete(asyncio.wait([a, b]))
def test_wait_with_iterator_of_tasks(self):
def gen():
when = yield
self.assertAlmostEqual(0.1, when)
when = yield 0
self.assertAlmostEqual(0.15, when)
yield 0.15
loop = self.new_test_loop(gen)
a = self.new_task(loop, asyncio.sleep(0.1))
b = self.new_task(loop, asyncio.sleep(0.15))
async def foo():
done, pending = await asyncio.wait(iter([b, a]))
self.assertEqual(done, set([a, b]))
self.assertEqual(pending, set())
return 42
res = loop.run_until_complete(self.new_task(loop, foo()))
self.assertEqual(res, 42)
self.assertAlmostEqual(0.15, loop.time())
def test_wait_generator(self):
async def func(a):
return a
loop = self.new_test_loop()
async def main():
tasks = (self.new_task(loop, func(i)) for i in range(10))
done, pending = await asyncio.wait(tasks, return_when=asyncio.ALL_COMPLETED)
self.assertEqual(len(done), 10)
self.assertEqual(len(pending), 0)
loop.run_until_complete(main())
def test_as_completed(self):
def gen():
yield 0
yield 0
yield 0.01
yield 0
async def sleeper(dt, x):
nonlocal time_shifted
await asyncio.sleep(dt)
completed.add(x)
if not time_shifted and 'a' in completed and 'b' in completed:
time_shifted = True
loop.advance_time(0.14)
return x
async def try_iterator(awaitables):
values = []
for f in asyncio.as_completed(awaitables):
values.append(await f)
return values
async def try_async_iterator(awaitables):
values = []
async for f in asyncio.as_completed(awaitables):
values.append(await f)
return values
for foo in try_iterator, try_async_iterator:
with self.subTest(method=foo.__name__):
loop = self.new_test_loop(gen)
# disable "slow callback" warning
loop.slow_callback_duration = 1.0
completed = set()
time_shifted = False
a = sleeper(0.01, 'a')
b = sleeper(0.01, 'b')
c = sleeper(0.15, 'c')
res = loop.run_until_complete(self.new_task(loop, foo([b, c, a])))
self.assertAlmostEqual(0.15, loop.time())
self.assertTrue('a' in res[:2])
self.assertTrue('b' in res[:2])
self.assertEqual(res[2], 'c')
def test_as_completed_same_tasks_in_as_out(self):
# Ensures that asynchronously iterating as_completed's iterator
# yields awaitables are the same awaitables that were passed in when
# those awaitables are futures.
async def try_async_iterator(awaitables):
awaitables_out = set()
async for out_aw in asyncio.as_completed(awaitables):
awaitables_out.add(out_aw)
return awaitables_out
async def coro(i):
return i
with contextlib.closing(asyncio.new_event_loop()) as loop:
# Coroutines shouldn't be yielded back as finished coroutines
# can't be re-used.
awaitables_in = frozenset(
(coro(0), coro(1), coro(2), coro(3))
)
awaitables_out = loop.run_until_complete(
try_async_iterator(awaitables_in)
)
if awaitables_in - awaitables_out != awaitables_in:
raise self.failureException('Got original coroutines '
'out of as_completed iterator.')
# Tasks should be yielded back.
coro_obj_a = coro('a')
task_b = loop.create_task(coro('b'))
coro_obj_c = coro('c')
task_d = loop.create_task(coro('d'))
awaitables_in = frozenset(
(coro_obj_a, task_b, coro_obj_c, task_d)
)
awaitables_out = loop.run_until_complete(
try_async_iterator(awaitables_in)
)
if awaitables_in & awaitables_out != {task_b, task_d}:
raise self.failureException('Only tasks should be yielded '
'from as_completed iterator '
'as-is.')
def test_as_completed_with_timeout(self):
def gen():
yield
yield 0
yield 0
yield 0.1
async def try_iterator():
values = []
for f in asyncio.as_completed([a, b], timeout=0.12):
if values:
loop.advance_time(0.02)
try:
v = await f
values.append((1, v))
except asyncio.TimeoutError as exc:
values.append((2, exc))
return values
async def try_async_iterator():
values = []
try:
async for f in asyncio.as_completed([a, b], timeout=0.12):
v = await f
values.append((1, v))
loop.advance_time(0.02)
except asyncio.TimeoutError as exc:
values.append((2, exc))
return values
for foo in try_iterator, try_async_iterator:
with self.subTest(method=foo.__name__):
loop = self.new_test_loop(gen)
a = loop.create_task(asyncio.sleep(0.1, 'a'))
b = loop.create_task(asyncio.sleep(0.15, 'b'))
res = loop.run_until_complete(self.new_task(loop, foo()))
self.assertEqual(len(res), 2, res)
self.assertEqual(res[0], (1, 'a'))
self.assertEqual(res[1][0], 2)
self.assertIsInstance(res[1][1], asyncio.TimeoutError)
self.assertAlmostEqual(0.12, loop.time())
# move forward to close generator
loop.advance_time(10)
loop.run_until_complete(asyncio.wait([a, b]))
def test_as_completed_with_unused_timeout(self):
def gen():
yield
yield 0
yield 0.01
async def try_iterator():
for f in asyncio.as_completed([a], timeout=1):
v = await f
self.assertEqual(v, 'a')
async def try_async_iterator():
async for f in asyncio.as_completed([a], timeout=1):
v = await f
self.assertEqual(v, 'a')
for foo in try_iterator, try_async_iterator:
with self.subTest(method=foo.__name__):
a = asyncio.sleep(0.01, 'a')
loop = self.new_test_loop(gen)
loop.run_until_complete(self.new_task(loop, foo()))
loop.close()
def test_as_completed_resume_iterator(self):
# Test that as_completed returns an iterator that can be resumed
# the next time iteration is performed (i.e. if __iter__ is called
# again)
async def try_iterator(awaitables):
iterations = 0
iterator = asyncio.as_completed(awaitables)
collected = []
for f in iterator:
collected.append(await f)
iterations += 1
if iterations == 2:
break
self.assertEqual(len(collected), 2)
# Resume same iterator:
for f in iterator:
collected.append(await f)
return collected
async def try_async_iterator(awaitables):
iterations = 0
iterator = asyncio.as_completed(awaitables)
collected = []
async for f in iterator:
collected.append(await f)
iterations += 1
if iterations == 2:
break
self.assertEqual(len(collected), 2)
# Resume same iterator:
async for f in iterator:
collected.append(await f)
return collected
async def coro(i):
return i
with contextlib.closing(asyncio.new_event_loop()) as loop:
for foo in try_iterator, try_async_iterator:
with self.subTest(method=foo.__name__):
results = loop.run_until_complete(
foo((coro(0), coro(1), coro(2), coro(3)))
)
self.assertCountEqual(results, (0, 1, 2, 3))
def test_as_completed_reverse_wait(self):
# Tests the plain iterator style of as_completed iteration to
# ensure that the first future awaited resolves to the first
# completed awaitable from the set we passed in, even if it wasn't
# the first future generated by as_completed.
def gen():
yield 0
yield 0.05
yield 0
loop = self.new_test_loop(gen)
a = asyncio.sleep(0.05, 'a')
b = asyncio.sleep(0.10, 'b')
fs = {a, b}
async def test():
futs = list(asyncio.as_completed(fs))
self.assertEqual(len(futs), 2)
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):
# Ensure that more than one future or coroutine yielded from
# as_completed can be awaited concurrently.
def gen():
when = yield
self.assertAlmostEqual(0.05, when)
when = yield 0
self.assertAlmostEqual(0.05, when)
yield 0.05
async def try_iterator(fs):
return list(asyncio.as_completed(fs))
async def try_async_iterator(fs):
return [f async for f in asyncio.as_completed(fs)]
for runner in try_iterator, try_async_iterator:
with self.subTest(method=runner.__name__):
a = asyncio.sleep(0.05, 'a')
b = asyncio.sleep(0.05, 'b')
fs = {a, b}
async def test():
futs = await runner(fs)
self.assertEqual(len(futs), 2)
done, pending = await asyncio.wait(
[asyncio.ensure_future(fut) for fut in futs]
)
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):
async def coro(s):
return s
async def try_iterator():
result = []
c = coro('ham')
for f in asyncio.as_completed([c, c, coro('spam')]):
result.append(await f)
return result
async def try_async_iterator():
result = []
c = coro('ham')
async for f in asyncio.as_completed([c, c, coro('spam')]):
result.append(await f)
return result
for runner in try_iterator, try_async_iterator:
with self.subTest(method=runner.__name__):
fut = self.new_task(self.loop, runner())
self.loop.run_until_complete(fut)
result = fut.result()
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)
with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
futs = asyncio.as_completed([a])
list(futs)
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_sleep(self):
def gen():
when = yield
self.assertAlmostEqual(0.05, when)
when = yield 0.05
self.assertAlmostEqual(0.1, when)
yield 0.05
loop = self.new_test_loop(gen)
async def sleeper(dt, arg):
await asyncio.sleep(dt/2)
res = await asyncio.sleep(dt/2, arg)
return res
t = self.new_task(loop, sleeper(0.1, 'yeah'))
loop.run_until_complete(t)
self.assertTrue(t.done())
self.assertEqual(t.result(), 'yeah')
self.assertAlmostEqual(0.1, loop.time())
def test_sleep_when_delay_is_nan(self):
def gen():
yield
loop = self.new_test_loop(gen)
async def sleeper():
await asyncio.sleep(float("nan"))
t = self.new_task(loop, sleeper())
with self.assertRaises(ValueError):
loop.run_until_complete(t)
def test_sleep_cancel(self):
def gen():
when = yield
self.assertAlmostEqual(10.0, when)
yield 0
loop = self.new_test_loop(gen)
t = self.new_task(loop, asyncio.sleep(10.0, 'yeah'))
handle = None
orig_call_later = loop.call_later
def call_later(delay, callback, *args):
nonlocal handle
handle = orig_call_later(delay, callback, *args)
return handle
loop.call_later = call_later
test_utils.run_briefly(loop)
self.assertFalse(handle._cancelled)
t.cancel()
test_utils.run_briefly(loop)
self.assertTrue(handle._cancelled)
def test_task_cancel_sleeping_task(self):
def gen():
when = yield
self.assertAlmostEqual(0.1, when)
when = yield 0
self.assertAlmostEqual(5000, when)
yield 0.1
loop = self.new_test_loop(gen)
async def sleep(dt):
await asyncio.sleep(dt)
async def doit():
sleeper = self.new_task(loop, sleep(5000))
loop.call_later(0.1, sleeper.cancel)
try:
await sleeper
except asyncio.CancelledError:
return 'cancelled'
else:
return 'slept in'
doer = doit()
self.assertEqual(loop.run_until_complete(doer), 'cancelled')
self.assertAlmostEqual(0.1, loop.time())
def test_task_cancel_waiter_future(self):
fut = self.new_future(self.loop)
async def coro():
await fut
task = self.new_task(self.loop, coro())
test_utils.run_briefly(self.loop)
self.assertIs(task._fut_waiter, fut)
task.cancel()
test_utils.run_briefly(self.loop)
self.assertRaises(
asyncio.CancelledError, self.loop.run_until_complete, task)
self.assertIsNone(task._fut_waiter)
self.assertTrue(fut.cancelled())
def test_task_set_methods(self):
async def notmuch():
return 'ko'
gen = notmuch()
task = self.new_task(self.loop, gen)
with self.assertRaisesRegex(RuntimeError, 'not support set_result'):
task.set_result('ok')
with self.assertRaisesRegex(RuntimeError, 'not support set_exception'):
task.set_exception(ValueError())
self.assertEqual(
self.loop.run_until_complete(task),
'ko')
def test_step_result_future(self):
# If coroutine returns future, task waits on this future.
class Fut(asyncio.Future):
def __init__(self, *args, **kwds):
self.cb_added = False
super().__init__(*args, **kwds)
def add_done_callback(self, *args, **kwargs):
self.cb_added = True
super().add_done_callback(*args, **kwargs)
fut = Fut(loop=self.loop)
result = None
async def wait_for_future():
nonlocal result
result = await fut
t = self.new_task(self.loop, wait_for_future())
test_utils.run_briefly(self.loop)
self.assertTrue(fut.cb_added)
res = object()
fut.set_result(res)
test_utils.run_briefly(self.loop)
self.assertIs(res, result)
self.assertTrue(t.done())
self.assertIsNone(t.result())
def test_baseexception_during_cancel(self):
def gen():
when = yield
self.assertAlmostEqual(10.0, when)
yield 0
loop = self.new_test_loop(gen)
async def sleeper():
await asyncio.sleep(10)
base_exc = SystemExit()
async def notmutch():
try:
await sleeper()
except asyncio.CancelledError:
raise base_exc
task = self.new_task(loop, notmutch())
test_utils.run_briefly(loop)
task.cancel()
self.assertFalse(task.done())
self.assertRaises(SystemExit, test_utils.run_briefly, loop)
self.assertTrue(task.done())
self.assertFalse(task.cancelled())
self.assertIs(task.exception(), base_exc)
@ignore_warnings(category=DeprecationWarning)
def test_iscoroutinefunction(self):
def fn():
pass
self.assertFalse(asyncio.iscoroutinefunction(fn))
def fn1():
yield
self.assertFalse(asyncio.iscoroutinefunction(fn1))
async def fn2():
pass
self.assertTrue(asyncio.iscoroutinefunction(fn2))
self.assertFalse(asyncio.iscoroutinefunction(mock.Mock()))
self.assertTrue(asyncio.iscoroutinefunction(mock.AsyncMock()))
@ignore_warnings(category=DeprecationWarning)
def test_coroutine_non_gen_function(self):
async def func():
return 'test'
self.assertTrue(asyncio.iscoroutinefunction(func))
coro = func()
self.assertTrue(asyncio.iscoroutine(coro))
res = self.loop.run_until_complete(coro)
self.assertEqual(res, 'test')
def test_coroutine_non_gen_function_return_future(self):
fut = self.new_future(self.loop)
async def func():
return fut
async def coro():
fut.set_result('test')
t1 = self.new_task(self.loop, func())
t2 = self.new_task(self.loop, coro())
res = self.loop.run_until_complete(t1)
self.assertEqual(res, fut)
self.assertIsNone(t2.result())
def test_current_task(self):
self.assertIsNone(asyncio.current_task(loop=self.loop))
async def coro(loop):
self.assertIs(asyncio.current_task(), task)
self.assertIs(asyncio.current_task(None), task)
self.assertIs(asyncio.current_task(), task)
task = self.new_task(self.loop, coro(self.loop))
self.loop.run_until_complete(task)
self.assertIsNone(asyncio.current_task(loop=self.loop))
def test_current_task_with_interleaving_tasks(self):
self.assertIsNone(asyncio.current_task(loop=self.loop))
fut1 = self.new_future(self.loop)
fut2 = self.new_future(self.loop)
async def coro1(loop):
self.assertTrue(asyncio.current_task() is task1)
await fut1
self.assertTrue(asyncio.current_task() is task1)
fut2.set_result(True)
async def coro2(loop):
self.assertTrue(asyncio.current_task() is task2)
fut1.set_result(True)
await fut2
self.assertTrue(asyncio.current_task() is task2)
task1 = self.new_task(self.loop, coro1(self.loop))
task2 = self.new_task(self.loop, coro2(self.loop))
self.loop.run_until_complete(asyncio.wait((task1, task2)))
self.assertIsNone(asyncio.current_task(loop=self.loop))
# Some thorough tests for cancellation propagation through
# coroutines, tasks and wait().
def test_yield_future_passes_cancel(self):
# Cancelling outer() cancels inner() cancels waiter.
proof = 0
waiter = self.new_future(self.loop)
async def inner():
nonlocal proof
try:
await waiter
except asyncio.CancelledError:
proof += 1
raise
else:
self.fail('got past sleep() in inner()')
async def outer():
nonlocal proof
try:
await inner()
except asyncio.CancelledError:
proof += 100 # Expect this path.
else:
proof += 10
f = asyncio.ensure_future(outer(), loop=self.loop)
test_utils.run_briefly(self.loop)
f.cancel()
self.loop.run_until_complete(f)
self.assertEqual(proof, 101)
self.assertTrue(waiter.cancelled())
def test_yield_wait_does_not_shield_cancel(self):
# Cancelling outer() makes wait() return early, leaves inner()
# running.
proof = 0
waiter = self.new_future(self.loop)
async def inner():
nonlocal proof
await waiter
proof += 1
async def outer():
nonlocal proof
with self.assertWarns(DeprecationWarning):
d, p = await asyncio.wait([asyncio.create_task(inner())])
proof += 100
f = asyncio.ensure_future(outer(), loop=self.loop)
test_utils.run_briefly(self.loop)
f.cancel()
self.assertRaises(
asyncio.CancelledError, self.loop.run_until_complete, f)
waiter.set_result(None)
test_utils.run_briefly(self.loop)
self.assertEqual(proof, 1)
def test_shield_result(self):
inner = self.new_future(self.loop)
outer = asyncio.shield(inner)
inner.set_result(42)
res = self.loop.run_until_complete(outer)
self.assertEqual(res, 42)
def test_shield_exception(self):
inner = self.new_future(self.loop)
outer = asyncio.shield(inner)
test_utils.run_briefly(self.loop)
exc = RuntimeError('expected')
inner.set_exception(exc)
test_utils.run_briefly(self.loop)
self.assertIs(outer.exception(), exc)
def test_shield_cancel_inner(self):
inner = self.new_future(self.loop)
outer = asyncio.shield(inner)
test_utils.run_briefly(self.loop)
inner.cancel()
test_utils.run_briefly(self.loop)
self.assertTrue(outer.cancelled())
def test_shield_cancel_outer(self):
inner = self.new_future(self.loop)
outer = asyncio.shield(inner)
test_utils.run_briefly(self.loop)
outer.cancel()
test_utils.run_briefly(self.loop)
self.assertTrue(outer.cancelled())
self.assertEqual(0, 0 if outer._callbacks is None else len(outer._callbacks))
def test_shield_shortcut(self):
fut = self.new_future(self.loop)
fut.set_result(42)
res = self.loop.run_until_complete(asyncio.shield(fut))
self.assertEqual(res, 42)
def test_shield_effect(self):
# Cancelling outer() does not affect inner().
proof = 0
waiter = self.new_future(self.loop)
async def inner():
nonlocal proof
await waiter
proof += 1
async def outer():
nonlocal proof
await asyncio.shield(inner())
proof += 100
f = asyncio.ensure_future(outer(), loop=self.loop)
test_utils.run_briefly(self.loop)
f.cancel()
with self.assertRaises(asyncio.CancelledError):
self.loop.run_until_complete(f)
waiter.set_result(None)
test_utils.run_briefly(self.loop)
self.assertEqual(proof, 1)
def test_shield_gather(self):
child1 = self.new_future(self.loop)
child2 = self.new_future(self.loop)
parent = asyncio.gather(child1, child2)
outer = asyncio.shield(parent)
test_utils.run_briefly(self.loop)
outer.cancel()
test_utils.run_briefly(self.loop)
self.assertTrue(outer.cancelled())
child1.set_result(1)
child2.set_result(2)
test_utils.run_briefly(self.loop)
self.assertEqual(parent.result(), [1, 2])
def test_gather_shield(self):
child1 = self.new_future(self.loop)
child2 = self.new_future(self.loop)
inner1 = asyncio.shield(child1)
inner2 = asyncio.shield(child2)
parent = asyncio.gather(inner1, inner2)
test_utils.run_briefly(self.loop)
parent.cancel()
# This should cancel inner1 and inner2 but bot child1 and child2.
test_utils.run_briefly(self.loop)
self.assertIsInstance(parent.exception(), asyncio.CancelledError)
self.assertTrue(inner1.cancelled())
self.assertTrue(inner2.cancelled())
child1.set_result(1)
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.assertRaisesRegex(RuntimeError, 'no current event loop'):
asyncio.shield(inner)
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, undeprecated in 3.12
async def coro():
return 42
asyncio.set_event_loop(self.loop)
self.addCleanup(asyncio.set_event_loop, None)
outer = asyncio.shield(coro())
self.assertEqual(outer._loop, self.loop)
res = self.loop.run_until_complete(outer)
self.assertEqual(res, 42)
def test_as_completed_invalid_args(self):
# as_completed() expects a list of futures, not a future instance
# TypeError should be raised either on iterator construction or first
# iteration
# Plain iterator
fut = self.new_future(self.loop)
with self.assertRaises(TypeError):
iterator = asyncio.as_completed(fut)
next(iterator)
coro = coroutine_function()
with self.assertRaises(TypeError):
iterator = asyncio.as_completed(coro)
next(iterator)
coro.close()
# Async iterator
async def try_async_iterator(aw):
async for f in asyncio.as_completed(aw):
break
fut = self.new_future(self.loop)
with self.assertRaises(TypeError):
self.loop.run_until_complete(try_async_iterator(fut))
coro = coroutine_function()
with self.assertRaises(TypeError):
self.loop.run_until_complete(try_async_iterator(coro))
coro.close()
def test_wait_invalid_args(self):
fut = self.new_future(self.loop)
# wait() expects a list of futures, not a future instance
self.assertRaises(TypeError, self.loop.run_until_complete,
asyncio.wait(fut))
coro = coroutine_function()
self.assertRaises(TypeError, self.loop.run_until_complete,
asyncio.wait(coro))
coro.close()
# wait() expects at least a future
self.assertRaises(ValueError, self.loop.run_until_complete,
asyncio.wait([]))
def test_log_destroyed_pending_task(self):
Task = self.__class__.Task
async def kill_me(loop):
future = self.new_future(loop)
await future
# at this point, the only reference to kill_me() task is
# the Task._wakeup() method in future._callbacks
raise Exception("code never reached")
mock_handler = mock.Mock()
self.loop.set_debug(True)
self.loop.set_exception_handler(mock_handler)
# schedule the task
coro = kill_me(self.loop)
task = asyncio.ensure_future(coro, loop=self.loop)
self.assertEqual(self.all_tasks(loop=self.loop), {task})
asyncio.set_event_loop(None)
# execute the task so it waits for future
self.loop._run_once()
self.assertEqual(len(self.loop._ready), 0)
coro = None
source_traceback = task._source_traceback
task = None
# no more reference to kill_me() task: the task is destroyed by the GC
support.gc_collect()
self.assertEqual(self.all_tasks(loop=self.loop), set())
mock_handler.assert_called_with(self.loop, {
'message': 'Task was destroyed but it is pending!',
'task': mock.ANY,
'source_traceback': source_traceback,
})
mock_handler.reset_mock()
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_not_called_after_cancel(self, m_log):
loop = asyncio.new_event_loop()
self.set_event_loop(loop)
async def coro():
raise TypeError
async def runner():
task = self.new_task(loop, coro())
await asyncio.sleep(0.05)
task.cancel()
task = None
loop.run_until_complete(runner())
self.assertFalse(m_log.error.called)
def test_task_source_traceback(self):
self.loop.set_debug(True)
task = self.new_task(self.loop, coroutine_function())
lineno = sys._getframe().f_lineno - 1
self.assertIsInstance(task._source_traceback, list)
self.assertEqual(task._source_traceback[-2][:3],
(__file__,
lineno,
'test_task_source_traceback'))
self.loop.run_until_complete(task)
def test_cancel_gather_1(self):
"""Ensure that a gathering future refuses to be cancelled once all
children are done"""
loop = asyncio.new_event_loop()
self.addCleanup(loop.close)
fut = self.new_future(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
async def child_coro():
return await 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(_):
nonlocal cancel_result
cancel_result = gather_task.cancel()
fut.add_done_callback(cancelling_callback)
fut.set_result(42) # calls the cancelling_callback after fut is done()
# At this point the task should complete.
loop.run_until_complete(gather_task)
# Python issue #26923: asyncio.gather drops cancellation
self.assertEqual(cancel_result, False)
self.assertFalse(gather_task.cancelled())
self.assertEqual(gather_task.result(), [42])
def test_cancel_gather_2(self):
cases = [
((), ()),
((None,), ()),
(('my message',), ('my message',)),
# Non-string values should roundtrip.
((5,), (5,)),
]
for cancel_args, expected_args in cases:
with self.subTest(cancel_args=cancel_args):
loop = asyncio.new_event_loop()
self.addCleanup(loop.close)
async def test():
time = 0
while True:
time += 0.05
await asyncio.gather(asyncio.sleep(0.05),
return_exceptions=True)
if time > 1:
return
async def main():
qwe = self.new_task(loop, test())
await asyncio.sleep(0.2)
qwe.cancel(*cancel_args)
await qwe
try:
loop.run_until_complete(main())
except asyncio.CancelledError as exc:
self.assertEqual(exc.args, expected_args)
actual = get_innermost_context(exc)
self.assertEqual(
actual,
(asyncio.CancelledError, expected_args, 0),
)
else:
self.fail(
'gather() does not propagate CancelledError '
'raised by inner task to the gather() caller.'
)
def test_exception_traceback(self):
# See http://bugs.python.org/issue28843
async def foo():
1 / 0
async def main():
task = self.new_task(self.loop, foo())
await asyncio.sleep(0) # skip one loop iteration
self.assertIsNotNone(task.exception().__traceback__)
self.loop.run_until_complete(main())
@mock.patch('asyncio.base_events.logger')
def test_error_in_call_soon(self, m_log):
def call_soon(callback, *args, **kwargs):
raise ValueError
self.loop.call_soon = call_soon
async def coro():
pass
self.assertFalse(m_log.error.called)
with self.assertRaises(ValueError):
gen = coro()
try:
self.new_task(self.loop, gen)
finally:
gen.close()
gc.collect() # For PyPy or other GCs.
self.assertTrue(m_log.error.called)
message = m_log.error.call_args[0][0]
self.assertIn('Task was destroyed but it is pending', message)
self.assertEqual(self.all_tasks(self.loop), set())
def test_create_task_with_noncoroutine(self):
with self.assertRaisesRegex(TypeError,
"a coroutine was expected, got 123"):
self.new_task(self.loop, 123)
# test it for the second time to ensure that caching
# in asyncio.iscoroutine() doesn't break things.
with self.assertRaisesRegex(TypeError,
"a coroutine was expected, got 123"):
self.new_task(self.loop, 123)
def test_create_task_with_async_function(self):
async def coro():
pass
task = self.new_task(self.loop, coro())
self.assertIsInstance(task, self.Task)
self.loop.run_until_complete(task)
# test it for the second time to ensure that caching
# in asyncio.iscoroutine() doesn't break things.
task = self.new_task(self.loop, coro())
self.assertIsInstance(task, self.Task)
self.loop.run_until_complete(task)
def test_create_task_with_asynclike_function(self):
task = self.new_task(self.loop, CoroLikeObject())
self.assertIsInstance(task, self.Task)
self.assertEqual(self.loop.run_until_complete(task), 42)
# test it for the second time to ensure that caching
# in asyncio.iscoroutine() doesn't break things.
task = self.new_task(self.loop, CoroLikeObject())
self.assertIsInstance(task, self.Task)
self.assertEqual(self.loop.run_until_complete(task), 42)
def test_bare_create_task(self):
async def inner():
return 1
async def coro():
task = asyncio.create_task(inner())
self.assertIsInstance(task, self.Task)
ret = await task
self.assertEqual(1, ret)
self.loop.run_until_complete(coro())
def test_bare_create_named_task(self):
async def coro_noop():
pass
async def coro():
task = asyncio.create_task(coro_noop(), name='No-op')
self.assertEqual(task.get_name(), 'No-op')
await task
self.loop.run_until_complete(coro())
def test_context_1(self):
cvar = contextvars.ContextVar('cvar', default='nope')
async def sub():
await asyncio.sleep(0.01)
self.assertEqual(cvar.get(), 'nope')
cvar.set('something else')
async def main():
self.assertEqual(cvar.get(), 'nope')
subtask = self.new_task(loop, sub())
cvar.set('yes')
self.assertEqual(cvar.get(), 'yes')
await subtask
self.assertEqual(cvar.get(), 'yes')
loop = asyncio.new_event_loop()
try:
task = self.new_task(loop, main())
loop.run_until_complete(task)
finally:
loop.close()
def test_context_2(self):
cvar = contextvars.ContextVar('cvar', default='nope')
async def main():
def fut_on_done(fut):
# This change must not pollute the context
# of the "main()" task.
cvar.set('something else')
self.assertEqual(cvar.get(), 'nope')
for j in range(2):
fut = self.new_future(loop)
fut.add_done_callback(fut_on_done)
cvar.set(f'yes{j}')
loop.call_soon(fut.set_result, None)
await fut
self.assertEqual(cvar.get(), f'yes{j}')
for i in range(3):
# Test that task passed its context to add_done_callback:
cvar.set(f'yes{i}-{j}')
await asyncio.sleep(0.001)
self.assertEqual(cvar.get(), f'yes{i}-{j}')
loop = asyncio.new_event_loop()
try:
task = self.new_task(loop, main())
loop.run_until_complete(task)
finally:
loop.close()
self.assertEqual(cvar.get(), 'nope')
def test_context_3(self):
# Run 100 Tasks in parallel, each modifying cvar.
cvar = contextvars.ContextVar('cvar', default=-1)
async def sub(num):
for i in range(10):
cvar.set(num + i)
await asyncio.sleep(random.uniform(0.001, 0.05))
self.assertEqual(cvar.get(), num + i)
async def main():
tasks = []
for i in range(100):
task = loop.create_task(sub(random.randint(0, 10)))
tasks.append(task)
await asyncio.gather(*tasks)
loop = asyncio.new_event_loop()
try:
loop.run_until_complete(main())
finally:
loop.close()
self.assertEqual(cvar.get(), -1)
def test_context_4(self):
cvar = contextvars.ContextVar('cvar')
async def coro(val):
await asyncio.sleep(0)
cvar.set(val)
async def main():
ret = []
ctx = contextvars.copy_context()
ret.append(ctx.get(cvar))
t1 = self.new_task(loop, coro(1), context=ctx)
await t1
ret.append(ctx.get(cvar))
t2 = self.new_task(loop, coro(2), context=ctx)
await t2
ret.append(ctx.get(cvar))
return ret
loop = asyncio.new_event_loop()
try:
task = self.new_task(loop, main())
ret = loop.run_until_complete(task)
finally:
loop.close()
self.assertEqual([None, 1, 2], ret)
def test_context_5(self):
cvar = contextvars.ContextVar('cvar')
async def coro(val):
await asyncio.sleep(0)
cvar.set(val)
async def main():
ret = []
ctx = contextvars.copy_context()
ret.append(ctx.get(cvar))
t1 = asyncio.create_task(coro(1), context=ctx)
await t1
ret.append(ctx.get(cvar))
t2 = asyncio.create_task(coro(2), context=ctx)
await t2
ret.append(ctx.get(cvar))
return ret
loop = asyncio.new_event_loop()
try:
task = self.new_task(loop, main())
ret = loop.run_until_complete(task)
finally:
loop.close()
self.assertEqual([None, 1, 2], ret)
def test_context_6(self):
cvar = contextvars.ContextVar('cvar')
async def coro(val):
await asyncio.sleep(0)
cvar.set(val)
async def main():
ret = []
ctx = contextvars.copy_context()
ret.append(ctx.get(cvar))
t1 = loop.create_task(coro(1), context=ctx)
await t1
ret.append(ctx.get(cvar))
t2 = loop.create_task(coro(2), context=ctx)
await t2
ret.append(ctx.get(cvar))
return ret
loop = asyncio.new_event_loop()
try:
task = loop.create_task(main())
ret = loop.run_until_complete(task)
finally:
loop.close()
self.assertEqual([None, 1, 2], ret)
def test_get_coro(self):
loop = asyncio.new_event_loop()
coro = coroutine_function()
try:
task = self.new_task(loop, coro)
loop.run_until_complete(task)
self.assertIs(task.get_coro(), coro)
finally:
loop.close()
def test_get_context(self):
loop = asyncio.new_event_loop()
coro = coroutine_function()
context = contextvars.copy_context()
try:
task = self.new_task(loop, coro, context=context)
loop.run_until_complete(task)
self.assertIs(task.get_context(), context)
finally:
loop.close()
def add_subclass_tests(cls):
BaseTask = cls.Task
BaseFuture = cls.Future
if BaseTask is None or BaseFuture is None:
return cls
class CommonFuture:
def __init__(self, *args, **kwargs):
self.calls = collections.defaultdict(lambda: 0)
super().__init__(*args, **kwargs)
def add_done_callback(self, *args, **kwargs):
self.calls['add_done_callback'] += 1
return super().add_done_callback(*args, **kwargs)
class Task(CommonFuture, BaseTask):
pass
class Future(CommonFuture, BaseFuture):
pass
def test_subclasses_ctask_cfuture(self):
fut = self.Future(loop=self.loop)
async def func():
self.loop.call_soon(lambda: fut.set_result('spam'))
return await fut
task = self.Task(func(), loop=self.loop)
result = self.loop.run_until_complete(task)
self.assertEqual(result, 'spam')
self.assertEqual(
dict(task.calls),
{'add_done_callback': 1})
self.assertEqual(
dict(fut.calls),
{'add_done_callback': 1})
# Add patched Task & Future back to the test case
cls.Task = Task
cls.Future = Future
cls.all_tasks = tasks.all_tasks
# Add an extra unit-test
cls.test_subclasses_ctask_cfuture = test_subclasses_ctask_cfuture
# Disable the "test_task_source_traceback" test
# (the test is hardcoded for a particular call stack, which
# is slightly different for Task subclasses)
cls.test_task_source_traceback = None
return cls
class SetMethodsTest:
def test_set_result_causes_invalid_state(self):
Future = type(self).Future
self.loop.call_exception_handler = exc_handler = mock.Mock()
async def foo():
await asyncio.sleep(0.1)
return 10
coro = foo()
task = self.new_task(self.loop, coro)
Future.set_result(task, 'spam')
self.assertEqual(
self.loop.run_until_complete(task),
'spam')
exc_handler.assert_called_once()
exc = exc_handler.call_args[0][0]['exception']
with self.assertRaisesRegex(asyncio.InvalidStateError,
r'step\(\): already done'):
raise exc
coro.close()
def test_set_exception_causes_invalid_state(self):
class MyExc(Exception):
pass
Future = type(self).Future
self.loop.call_exception_handler = exc_handler = mock.Mock()
async def foo():
await asyncio.sleep(0.1)
return 10
coro = foo()
task = self.new_task(self.loop, coro)
Future.set_exception(task, MyExc())
with self.assertRaises(MyExc):
self.loop.run_until_complete(task)
exc_handler.assert_called_once()
exc = exc_handler.call_args[0][0]['exception']
with self.assertRaisesRegex(asyncio.InvalidStateError,
r'step\(\): already done'):
raise exc
coro.close()
@unittest.skipUnless(hasattr(futures, '_CFuture') and
hasattr(tasks, '_CTask'),
'requires the C _asyncio module')
class CTask_CFuture_Tests(BaseTaskTests, SetMethodsTest,
test_utils.TestCase):
Task = getattr(tasks, '_CTask', None)
Future = getattr(futures, '_CFuture', None)
all_tasks = getattr(tasks, '_c_all_tasks', None)
@support.refcount_test
def test_refleaks_in_task___init__(self):
gettotalrefcount = support.get_attribute(sys, 'gettotalrefcount')
async def coro():
pass
task = self.new_task(self.loop, coro())
self.loop.run_until_complete(task)
refs_before = gettotalrefcount()
for i in range(100):
task.__init__(coro(), loop=self.loop)
self.loop.run_until_complete(task)
self.assertAlmostEqual(gettotalrefcount() - refs_before, 0, delta=10)
def test_del__log_destroy_pending_segfault(self):
async def coro():
pass
task = self.new_task(self.loop, coro())
self.loop.run_until_complete(task)
with self.assertRaises(AttributeError):
del task._log_destroy_pending
@unittest.skipUnless(hasattr(futures, '_CFuture') and
hasattr(tasks, '_CTask'),
'requires the C _asyncio module')
@add_subclass_tests
class CTask_CFuture_SubclassTests(BaseTaskTests, test_utils.TestCase):
Task = getattr(tasks, '_CTask', None)
Future = getattr(futures, '_CFuture', None)
all_tasks = getattr(tasks, '_c_all_tasks', None)
@unittest.skipUnless(hasattr(tasks, '_CTask'),
'requires the C _asyncio module')
@add_subclass_tests
class CTaskSubclass_PyFuture_Tests(BaseTaskTests, test_utils.TestCase):
Task = getattr(tasks, '_CTask', None)
Future = futures._PyFuture
all_tasks = getattr(tasks, '_c_all_tasks', None)
@unittest.skipUnless(hasattr(futures, '_CFuture'),
'requires the C _asyncio module')
@add_subclass_tests
class PyTask_CFutureSubclass_Tests(BaseTaskTests, test_utils.TestCase):
Future = getattr(futures, '_CFuture', None)
Task = tasks._PyTask
all_tasks = tasks._py_all_tasks
@unittest.skipUnless(hasattr(tasks, '_CTask'),
'requires the C _asyncio module')
class CTask_PyFuture_Tests(BaseTaskTests, test_utils.TestCase):
Task = getattr(tasks, '_CTask', None)
Future = futures._PyFuture
all_tasks = getattr(tasks, '_c_all_tasks', None)
@unittest.skipUnless(hasattr(futures, '_CFuture'),
'requires the C _asyncio module')
class PyTask_CFuture_Tests(BaseTaskTests, test_utils.TestCase):
Task = tasks._PyTask
Future = getattr(futures, '_CFuture', None)
all_tasks = staticmethod(tasks._py_all_tasks)
class PyTask_PyFuture_Tests(BaseTaskTests, SetMethodsTest,
test_utils.TestCase):
Task = tasks._PyTask
Future = futures._PyFuture
all_tasks = staticmethod(tasks._py_all_tasks)
@add_subclass_tests
class PyTask_PyFuture_SubclassTests(BaseTaskTests, test_utils.TestCase):
Task = tasks._PyTask
Future = futures._PyFuture
@unittest.skipUnless(hasattr(tasks, '_CTask'),
'requires the C _asyncio module')
class CTask_Future_Tests(test_utils.TestCase):
def test_foobar(self):
class Fut(asyncio.Future):
@property
def get_loop(self):
raise AttributeError
async def coro():
await fut
return 'spam'
self.loop = asyncio.new_event_loop()
try:
fut = Fut(loop=self.loop)
self.loop.call_later(0.1, fut.set_result, 1)
task = self.loop.create_task(coro())
res = self.loop.run_until_complete(task)
finally:
self.loop.close()
self.assertEqual(res, 'spam')
class BaseTaskIntrospectionTests:
_register_task = None
_unregister_task = None
_enter_task = None
_leave_task = None
all_tasks = None
def test__register_task_1(self):
class TaskLike:
@property
def _loop(self):
return loop
def done(self):
return False
task = TaskLike()
loop = mock.Mock()
self.assertEqual(self.all_tasks(loop), set())
self._register_task(task)
self.assertEqual(self.all_tasks(loop), {task})
self._unregister_task(task)
def test__register_task_2(self):
class TaskLike:
def get_loop(self):
return loop
def done(self):
return False
task = TaskLike()
loop = mock.Mock()
self.assertEqual(self.all_tasks(loop), set())
self._register_task(task)
self.assertEqual(self.all_tasks(loop), {task})
self._unregister_task(task)
def test__register_task_3(self):
class TaskLike:
def get_loop(self):
return loop
def done(self):
return True
task = TaskLike()
loop = mock.Mock()
self.assertEqual(self.all_tasks(loop), set())
self._register_task(task)
self.assertEqual(self.all_tasks(loop), set())
self._unregister_task(task)
def test__enter_task(self):
task = mock.Mock()
loop = mock.Mock()
self.assertIsNone(asyncio.current_task(loop))
self._enter_task(loop, task)
self.assertIs(asyncio.current_task(loop), task)
self._leave_task(loop, task)
def test__enter_task_failure(self):
task1 = mock.Mock()
task2 = mock.Mock()
loop = mock.Mock()
self._enter_task(loop, task1)
with self.assertRaises(RuntimeError):
self._enter_task(loop, task2)
self.assertIs(asyncio.current_task(loop), task1)
self._leave_task(loop, task1)
def test__leave_task(self):
task = mock.Mock()
loop = mock.Mock()
self._enter_task(loop, task)
self._leave_task(loop, task)
self.assertIsNone(asyncio.current_task(loop))
def test__leave_task_failure1(self):
task1 = mock.Mock()
task2 = mock.Mock()
loop = mock.Mock()
self._enter_task(loop, task1)
with self.assertRaises(RuntimeError):
self._leave_task(loop, task2)
self.assertIs(asyncio.current_task(loop), task1)
self._leave_task(loop, task1)
def test__leave_task_failure2(self):
task = mock.Mock()
loop = mock.Mock()
with self.assertRaises(RuntimeError):
self._leave_task(loop, task)
self.assertIsNone(asyncio.current_task(loop))
def test__unregister_task(self):
task = mock.Mock()
loop = mock.Mock()
task.get_loop = lambda: loop
self._register_task(task)
self._unregister_task(task)
self.assertEqual(self.all_tasks(loop), set())
def test__unregister_task_not_registered(self):
task = mock.Mock()
loop = mock.Mock()
self._unregister_task(task)
self.assertEqual(self.all_tasks(loop), set())
class PyIntrospectionTests(test_utils.TestCase, BaseTaskIntrospectionTests):
_register_task = staticmethod(tasks._py_register_task)
_unregister_task = staticmethod(tasks._py_unregister_task)
_enter_task = staticmethod(tasks._py_enter_task)
_leave_task = staticmethod(tasks._py_leave_task)
all_tasks = staticmethod(tasks._py_all_tasks)
@unittest.skipUnless(hasattr(tasks, '_c_register_task'),
'requires the C _asyncio module')
class CIntrospectionTests(test_utils.TestCase, BaseTaskIntrospectionTests):
if hasattr(tasks, '_c_register_task'):
_register_task = staticmethod(tasks._c_register_task)
_unregister_task = staticmethod(tasks._c_unregister_task)
_enter_task = staticmethod(tasks._c_enter_task)
_leave_task = staticmethod(tasks._c_leave_task)
all_tasks = staticmethod(tasks._c_all_tasks)
else:
_register_task = _unregister_task = _enter_task = _leave_task = None
class BaseCurrentLoopTests:
current_task = None
def setUp(self):
super().setUp()
self.loop = asyncio.new_event_loop()
self.set_event_loop(self.loop)
def new_task(self, coro):
raise NotImplementedError
def test_current_task_no_running_loop(self):
self.assertIsNone(self.current_task(loop=self.loop))
def test_current_task_no_running_loop_implicit(self):
with self.assertRaisesRegex(RuntimeError, 'no running event loop'):
self.current_task()
def test_current_task_with_implicit_loop(self):
async def coro():
self.assertIs(self.current_task(loop=self.loop), task)
self.assertIs(self.current_task(None), task)
self.assertIs(self.current_task(), task)
task = self.new_task(coro())
self.loop.run_until_complete(task)
self.assertIsNone(self.current_task(loop=self.loop))
class PyCurrentLoopTests(BaseCurrentLoopTests, test_utils.TestCase):
current_task = staticmethod(tasks._py_current_task)
def new_task(self, coro):
return tasks._PyTask(coro, loop=self.loop)
@unittest.skipUnless(hasattr(tasks, '_CTask') and
hasattr(tasks, '_c_current_task'),
'requires the C _asyncio module')
class CCurrentLoopTests(BaseCurrentLoopTests, test_utils.TestCase):
if hasattr(tasks, '_c_current_task'):
current_task = staticmethod(tasks._c_current_task)
else:
current_task = None
def new_task(self, coro):
return getattr(tasks, '_CTask')(coro, loop=self.loop)
class GenericTaskTests(test_utils.TestCase):
def test_future_subclass(self):
self.assertTrue(issubclass(asyncio.Task, asyncio.Future))
@support.cpython_only
def test_asyncio_module_compiled(self):
# Because of circular imports it's easy to make _asyncio
# module non-importable. This is a simple test that will
# fail on systems where C modules were successfully compiled
# (hence the test for _functools etc), but _asyncio somehow didn't.
try:
import _functools # noqa: F401
import _json # noqa: F401
import _pickle # noqa: F401
except ImportError:
self.skipTest('C modules are not available')
else:
try:
import _asyncio # noqa: F401
except ImportError:
self.fail('_asyncio module is missing')
class GatherTestsBase:
def setUp(self):
super().setUp()
self.one_loop = self.new_test_loop()
self.other_loop = self.new_test_loop()
self.set_event_loop(self.one_loop, cleanup=False)
def _run_loop(self, loop):
while loop._ready:
test_utils.run_briefly(loop)
def _check_success(self, **kwargs):
a, b, c = [self.one_loop.create_future() for i in range(3)]
fut = self._gather(*self.wrap_futures(a, b, c), **kwargs)
cb = test_utils.MockCallback()
fut.add_done_callback(cb)
b.set_result(1)
a.set_result(2)
self._run_loop(self.one_loop)
self.assertEqual(cb.called, False)
self.assertFalse(fut.done())
c.set_result(3)
self._run_loop(self.one_loop)
cb.assert_called_once_with(fut)
self.assertEqual(fut.result(), [2, 1, 3])
def test_success(self):
self._check_success()
self._check_success(return_exceptions=False)
def test_result_exception_success(self):
self._check_success(return_exceptions=True)
def test_one_exception(self):
a, b, c, d, e = [self.one_loop.create_future() for i in range(5)]
fut = self._gather(*self.wrap_futures(a, b, c, d, e))
cb = test_utils.MockCallback()
fut.add_done_callback(cb)
exc = ZeroDivisionError()
a.set_result(1)
b.set_exception(exc)
self._run_loop(self.one_loop)
self.assertTrue(fut.done())
cb.assert_called_once_with(fut)
self.assertIs(fut.exception(), exc)
# Does nothing
c.set_result(3)
d.cancel()
e.set_exception(RuntimeError())
e.exception()
def test_return_exceptions(self):
a, b, c, d = [self.one_loop.create_future() for i in range(4)]
fut = self._gather(*self.wrap_futures(a, b, c, d),
return_exceptions=True)
cb = test_utils.MockCallback()
fut.add_done_callback(cb)
exc = ZeroDivisionError()
exc2 = RuntimeError()
b.set_result(1)
c.set_exception(exc)
a.set_result(3)
self._run_loop(self.one_loop)
self.assertFalse(fut.done())
d.set_exception(exc2)
self._run_loop(self.one_loop)
self.assertTrue(fut.done())
cb.assert_called_once_with(fut)
self.assertEqual(fut.result(), [3, 1, exc, exc2])
def test_env_var_debug(self):
code = '\n'.join((
'import asyncio.coroutines',
'print(asyncio.coroutines._is_debug_mode())'))
# Test with -E to not fail if the unit test was run with
# PYTHONASYNCIODEBUG set to a non-empty string
sts, stdout, stderr = assert_python_ok('-E', '-c', code)
self.assertEqual(stdout.rstrip(), b'False')
sts, stdout, stderr = assert_python_ok('-c', code,
PYTHONASYNCIODEBUG='',
PYTHONDEVMODE='')
self.assertEqual(stdout.rstrip(), b'False')
sts, stdout, stderr = assert_python_ok('-c', code,
PYTHONASYNCIODEBUG='1',
PYTHONDEVMODE='')
self.assertEqual(stdout.rstrip(), b'True')
sts, stdout, stderr = assert_python_ok('-E', '-c', code,
PYTHONASYNCIODEBUG='1',
PYTHONDEVMODE='')
self.assertEqual(stdout.rstrip(), b'False')
# -X dev
sts, stdout, stderr = assert_python_ok('-E', '-X', 'dev',
'-c', code)
self.assertEqual(stdout.rstrip(), b'True')
class FutureGatherTests(GatherTestsBase, test_utils.TestCase):
def wrap_futures(self, *futures):
return futures
def _gather(self, *args, **kwargs):
return asyncio.gather(*args, **kwargs)
def test_constructor_empty_sequence_without_loop(self):
with self.assertRaisesRegex(RuntimeError, 'no current event loop'):
asyncio.gather()
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_use_global_loop(self):
# Deprecated in 3.10, undeprecated in 3.12
asyncio.set_event_loop(self.one_loop)
self.addCleanup(asyncio.set_event_loop, None)
fut = asyncio.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_heterogenous_futures(self):
fut1 = self.one_loop.create_future()
fut2 = self.other_loop.create_future()
with self.assertRaises(ValueError):
asyncio.gather(fut1, fut2)
def test_constructor_homogenous_futures(self):
children = [self.other_loop.create_future() for i in range(3)]
fut = asyncio.gather(*children)
self.assertIs(fut._loop, self.other_loop)
self._run_loop(self.other_loop)
self.assertFalse(fut.done())
fut = asyncio.gather(*children)
self.assertIs(fut._loop, self.other_loop)
self._run_loop(self.other_loop)
self.assertFalse(fut.done())
def test_one_cancellation(self):
a, b, c, d, e = [self.one_loop.create_future() for i in range(5)]
fut = asyncio.gather(a, b, c, d, e)
cb = test_utils.MockCallback()
fut.add_done_callback(cb)
a.set_result(1)
b.cancel()
self._run_loop(self.one_loop)
self.assertTrue(fut.done())
cb.assert_called_once_with(fut)
self.assertFalse(fut.cancelled())
self.assertIsInstance(fut.exception(), asyncio.CancelledError)
# Does nothing
c.set_result(3)
d.cancel()
e.set_exception(RuntimeError())
e.exception()
def test_result_exception_one_cancellation(self):
a, b, c, d, e, f = [self.one_loop.create_future()
for i in range(6)]
fut = asyncio.gather(a, b, c, d, e, f, return_exceptions=True)
cb = test_utils.MockCallback()
fut.add_done_callback(cb)
a.set_result(1)
zde = ZeroDivisionError()
b.set_exception(zde)
c.cancel()
self._run_loop(self.one_loop)
self.assertFalse(fut.done())
d.set_result(3)
e.cancel()
rte = RuntimeError()
f.set_exception(rte)
res = self.one_loop.run_until_complete(fut)
self.assertIsInstance(res[2], asyncio.CancelledError)
self.assertIsInstance(res[4], asyncio.CancelledError)
res[2] = res[4] = None
self.assertEqual(res, [1, zde, None, 3, None, rte])
cb.assert_called_once_with(fut)
class CoroutineGatherTests(GatherTestsBase, test_utils.TestCase):
def wrap_futures(self, *futures):
coros = []
for fut in futures:
async def coro(fut=fut):
return await fut
coros.append(coro())
return coros
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.assertRaisesRegex(RuntimeError, 'no current event loop'):
asyncio.gather(gen1, gen2)
def test_constructor_use_running_loop(self):
async def coro():
return 'abc'
gen1 = coro()
gen2 = coro()
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)
def test_constructor_use_global_loop(self):
# Deprecated in 3.10, undeprecated in 3.12
async def coro():
return 'abc'
asyncio.set_event_loop(self.other_loop)
self.addCleanup(asyncio.set_event_loop, None)
gen1 = coro()
gen2 = coro()
fut = asyncio.gather(gen1, gen2)
self.assertIs(fut._loop, self.other_loop)
self.other_loop.run_until_complete(fut)
def test_duplicate_coroutines(self):
async def coro(s):
return s
c = coro('abc')
fut = self._gather(c, c, coro('def'), c)
self._run_loop(self.one_loop)
self.assertEqual(fut.result(), ['abc', 'abc', 'def', 'abc'])
def test_cancellation_broadcast(self):
# Cancelling outer() cancels all children.
proof = 0
waiter = self.one_loop.create_future()
async def inner():
nonlocal proof
await waiter
proof += 1
child1 = asyncio.ensure_future(inner(), loop=self.one_loop)
child2 = asyncio.ensure_future(inner(), loop=self.one_loop)
gatherer = None
async def outer():
nonlocal proof, gatherer
gatherer = asyncio.gather(child1, child2)
await gatherer
proof += 100
f = asyncio.ensure_future(outer(), loop=self.one_loop)
test_utils.run_briefly(self.one_loop)
self.assertTrue(f.cancel())
with self.assertRaises(asyncio.CancelledError):
self.one_loop.run_until_complete(f)
self.assertFalse(gatherer.cancel())
self.assertTrue(waiter.cancelled())
self.assertTrue(child1.cancelled())
self.assertTrue(child2.cancelled())
test_utils.run_briefly(self.one_loop)
self.assertEqual(proof, 0)
def test_exception_marking(self):
# Test for the first line marked "Mark exception retrieved."
async def inner(f):
await f
raise RuntimeError('should not be ignored')
a = self.one_loop.create_future()
b = self.one_loop.create_future()
async def outer():
await asyncio.gather(inner(a), inner(b))
f = asyncio.ensure_future(outer(), loop=self.one_loop)
test_utils.run_briefly(self.one_loop)
a.set_result(None)
test_utils.run_briefly(self.one_loop)
b.set_result(None)
test_utils.run_briefly(self.one_loop)
self.assertIsInstance(f.exception(), RuntimeError)
def test_issue46672(self):
with mock.patch(
'asyncio.base_events.BaseEventLoop.call_exception_handler',
):
async def coro(s):
return s
c = coro('abc')
with self.assertRaises(TypeError):
self._gather(c, {})
self._run_loop(self.one_loop)
# NameError should not happen:
self.one_loop.call_exception_handler.assert_not_called()
class RunCoroutineThreadsafeTests(test_utils.TestCase):
"""Test case for asyncio.run_coroutine_threadsafe."""
def setUp(self):
super().setUp()
self.loop = asyncio.new_event_loop()
self.set_event_loop(self.loop) # Will cleanup properly
async def add(self, a, b, fail=False, cancel=False):
"""Wait 0.05 second and return a + b."""
await asyncio.sleep(0.05)
if fail:
raise RuntimeError("Fail!")
if cancel:
asyncio.current_task(self.loop).cancel()
await asyncio.sleep(0)
return a + b
def target(self, fail=False, cancel=False, timeout=None,
advance_coro=False):
"""Run add coroutine in the event loop."""
coro = self.add(1, 2, fail=fail, cancel=cancel)
future = asyncio.run_coroutine_threadsafe(coro, self.loop)
if advance_coro:
# this is for test_run_coroutine_threadsafe_task_factory_exception;
# otherwise it spills errors and breaks **other** unittests, since
# 'target' is interacting with threads.
# With this call, `coro` will be advanced.
self.loop.call_soon_threadsafe(coro.send, None)
try:
return future.result(timeout)
finally:
future.done() or future.cancel()
def test_run_coroutine_threadsafe(self):
"""Test coroutine submission from a thread to an event loop."""
future = self.loop.run_in_executor(None, self.target)
result = self.loop.run_until_complete(future)
self.assertEqual(result, 3)
def test_run_coroutine_threadsafe_with_exception(self):
"""Test coroutine submission from a thread to an event loop
when an exception is raised."""
future = self.loop.run_in_executor(None, self.target, True)
with self.assertRaises(RuntimeError) as exc_context:
self.loop.run_until_complete(future)
self.assertIn("Fail!", exc_context.exception.args)
def test_run_coroutine_threadsafe_with_timeout(self):
"""Test coroutine submission from a thread to an event loop
when a timeout is raised."""
callback = lambda: self.target(timeout=0)
future = self.loop.run_in_executor(None, callback)
with self.assertRaises(asyncio.TimeoutError):
self.loop.run_until_complete(future)
test_utils.run_briefly(self.loop)
# Check that there's no pending task (add has been cancelled)
for task in asyncio.all_tasks(self.loop):
self.assertTrue(task.done())
def test_run_coroutine_threadsafe_task_cancelled(self):
"""Test coroutine submission from a thread to an event loop
when the task is cancelled."""
callback = lambda: self.target(cancel=True)
future = self.loop.run_in_executor(None, callback)
with self.assertRaises(asyncio.CancelledError):
self.loop.run_until_complete(future)
def test_run_coroutine_threadsafe_task_factory_exception(self):
"""Test coroutine submission from a thread to an event loop
when the task factory raise an exception."""
def task_factory(loop, coro):
raise NameError
run = self.loop.run_in_executor(
None, lambda: self.target(advance_coro=True))
# Set exception handler
callback = test_utils.MockCallback()
self.loop.set_exception_handler(callback)
# Set corrupted task factory
self.addCleanup(self.loop.set_task_factory,
self.loop.get_task_factory())
self.loop.set_task_factory(task_factory)
# Run event loop
with self.assertRaises(NameError) as exc_context:
self.loop.run_until_complete(run)
# Check exceptions
self.assertEqual(len(callback.call_args_list), 1)
(loop, context), kwargs = callback.call_args
self.assertEqual(context['exception'], exc_context.exception)
class SleepTests(test_utils.TestCase):
def setUp(self):
super().setUp()
self.loop = asyncio.new_event_loop()
self.set_event_loop(self.loop)
def tearDown(self):
self.loop.close()
self.loop = None
super().tearDown()
def test_sleep_zero(self):
result = 0
def inc_result(num):
nonlocal result
result += num
async def coro():
self.loop.call_soon(inc_result, 1)
self.assertEqual(result, 0)
num = await asyncio.sleep(0, result=10)
self.assertEqual(result, 1) # inc'ed by call_soon
inc_result(num) # num should be 11
self.loop.run_until_complete(coro())
self.assertEqual(result, 11)
class CompatibilityTests(test_utils.TestCase):
# Tests for checking a bridge between old-styled coroutines
# and async/await syntax
def setUp(self):
super().setUp()
self.loop = asyncio.new_event_loop()
self.set_event_loop(self.loop)
def tearDown(self):
self.loop.close()
self.loop = None
super().tearDown()
if __name__ == '__main__':
unittest.main()
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