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gh-90908: Document asyncio.Task.cancelling() and asyncio.Task.uncancel() #95253

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Merged
gvanrossum merged 12 commits into from
Oct 1, 2022
Merged

gh-90908: Document asyncio.Task.cancelling() and asyncio.Task.uncancel() #95253

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708cb27
gh-90908: Document asyncio.Task.cancelling() and asyncio.Task.uncancel()
ambv Jul 25, 2022
0203e01
Reword `uncancel()` example, move cancellation methods down in docs
ambv Jul 26, 2022
4a6a2fe
Apply suggestions from Guido's code review
ambv Jul 27, 2022
ad49eb0
Re-fix typo from ce195cbd98b48370326d9e1bc5ff74e828571850
ambv Jul 27, 2022
4c56381
Move example to tests and expand on why it's doing what it's doing
ambv Jul 28, 2022
13515f3
Use a semicolon in comment to make text flow more obvious
ambv Jul 28, 2022
f0a215d
Expand the example test by showing cancelling() is 0
ambv Jul 29, 2022
f3bcc6f
Rewording nit
gvanrossum Sep 26, 2022
26cf287
attempt to -> call
gvanrossum Sep 26, 2022
9296af0
Be precise about cancelling()
gvanrossum Sep 26, 2022
4114a79
Merge branch 'main' into document-asyncio-task-uncancel
gvanrossum Sep 26, 2022
50850de
Merge branch 'main' into document-asyncio-task-uncancel
gvanrossum Sep 26, 2022
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Expand the example test by showing cancelling() is 0
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@ambv
ambv committed Jul 29, 2022
commit f0a215d7ffbf7ff402461127c6cdb386648d320a
15 changes: 11 additions & 4 deletions Lib/test/test_asyncio/test_tasks.py
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Expand Up @@ -622,13 +622,18 @@ def on_timeout():
# code might have been nested (think multiple timeouts). See
# commit 7fce1063b6e5a366f8504e039a8ccdd6944625cd for
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@gvanrossum gvanrossum Aug 1, 2022

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Note that commit 7d611b4 changes the behavior again.

# details.
# 5. we only convert CancelledError to TimeoutError; if the user
# code raised a different exception due to the cancellation
# (like a ConnectionLostError from a database client), we
# propagate it.
# 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
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@gvanrossum gvanrossum Aug 1, 2022

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"Those checks" == (2), (4), (5), right? Because (1) and (3) don't describe "checks".

Other than that nit, these comments seem correct, and the code looks so too (but I'm not taking money :-).

(Another nit: the huge comment interrupts the logic. Maybe move it to the top of the test function?)

# 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)
Expand All @@ -648,6 +653,7 @@ def on_timeout():
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))
Expand All @@ -657,6 +663,7 @@ def on_timeout():
self.assertFalse(timed_out)
self.assertTrue(structured_block_finished)
self.assertTrue(outer_code_reached)
self.assertEqual(t2.cancelling(), 0)

def test_cancel(self):

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