python
Cancelled lock waiter wakes up the next one if any
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)
@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?
Looks like this PR is doing a right thing. @msornay please update the tests, and I will merge it.
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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.
Please reopen this PR at https://github.com/python/cpython. This repo is going to be deleted soon.