Skip to content

bpo-31033: Add a msg argument to Future.cancel() and Task.cancel() #19979

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
cjerdonek merged 8 commits into from
May 15, 2020
Merged

bpo-31033: Add a msg argument to Future.cancel() and Task.cancel() #19979

Changes from 1 commit
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
0ed5e4e
Add argument clinic changes.
cjerdonek May 7, 2020
5c8489f
Add failing tests.
cjerdonek May 7, 2020
58a2257
Add C implementation.
cjerdonek May 7, 2020
86e13df
Add pure Python implementation.
cjerdonek May 7, 2020
403baa2
Add docs and NEWS entry.
cjerdonek May 7, 2020
6b133a2
Make None msg result in no arguments.
cjerdonek May 8, 2020
a0434c9
Test the getter and setter.
cjerdonek May 8, 2020
22a54cc
Remove the _create_cancelled_error() helper function.
cjerdonek May 15, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
Add failing tests.
  • Loading branch information
@cjerdonek
cjerdonek committed May 14, 2020
commit 5c8489f337225a066b057b18ce9b23b6c18d29aa
141 changes: 116 additions & 25 deletions Lib/test/test_asyncio/test_tasks.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -514,6 +514,86 @@ async def task():
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,)),
((None,), (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)

def test_cancel_with_message_then_future_exception(self):
# Test Future.exception() after calling cancel() with a message.
cases = [
((), (None,)),
((None,), (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)

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',))

def test_cancel_yield(self):
with self.assertWarns(DeprecationWarning):
@asyncio.coroutine
Expand Down Expand Up @@ -2238,31 +2318,42 @@ def cancelling_callback(_):
self.assertEqual(gather_task.result(), [42])

def test_cancel_gather_2(self):
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,
loop=loop)
if time > 1:
return

async def main():
qwe = self.new_task(loop, test())
await asyncio.sleep(0.2)
qwe.cancel()
try:
await qwe
except asyncio.CancelledError:
pass
else:
self.fail('gather did not propagate the cancellation request')

loop.run_until_complete(main())
cases = [
((), (None,)),
((None,), (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,
loop=loop)
if time > 1:
return

async def main():
qwe = self.new_task(loop, test())
await asyncio.sleep(0.2)
qwe.cancel(*cancel_args)
try:
await qwe
except asyncio.CancelledError as exc:
self.assertEqual(exc.args, expected_args)
else:
self.fail('gather did not propagate the cancellation '
'request')

loop.run_until_complete(main())

def test_exception_traceback(self):
# See http://bugs.python.org/issue28843
Expand Down