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python / asyncio

asyncio historical repository
https://docs.python.org/3/library/asyncio.html
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Cancelled lock waiter wakes up the next one if any #467

Closed msornay closed 6 months ago

msornay commented 7 years ago

Fixes http://bugs.python.org/issue27585

Without the fix the unit test deadlock, I haven't managed to make it fail (using wait_for() seems to avoid the deadlock)

1st1 commented 7 years ago

@gvanrossum @asvetlov I'm not sure I can review this (I never touched/used that code). Can you take a look if you have time and you are familiar with the code?

gvanrossum commented 7 years ago

Sorry, I can't do it this week or next.

1st1 commented 7 years ago

Looks like this PR is doing a right thing. @msornay please update the tests, and I will merge it.

the-knights-who-say-ni commented 7 years ago

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msornay commented 7 years ago

Everything should be in order.

pklanke commented 7 years ago

After applying patch #363 and #467 to Python 3.5.2, the dead-lock did indeed no longer occur, but the opposite did; Sometimes on releasing the lock, a RuntimeError exception is raised telling me the lock was not acquired.

lock.acquire() try: ... do stuff ... finally: lock.release() # RuntimeError occured here

So far, I did not manage to create a simple test case, and I know this does not help much without it, but should someone experience this same behavior, then just know you are not the only one.

1st1 commented 7 years ago

Please reopen this PR at https://github.com/python/cpython. This repo is going to be deleted soon.