Skip to content

Conversation

miss-islington
Copy link
Contributor

@miss-islington miss-islington commented Sep 20, 2022

At Python exit, sometimes a thread holding the GIL can wait forever
for a thread (usually a daemon thread) which requested to drop the
GIL, whereas the thread already exited. To fix the race condition,
the thread which requested the GIL drop now resets its request before
exiting.

take_gil() now calls RESET_GIL_DROP_REQUEST() before
PyThread_exit_thread() if it called SET_GIL_DROP_REQUEST to fix a
race condition with drop_gil().

Issue discovered and analyzed by Mingliang ZHAO.

(cherry picked from commit 04f4977)
(cherry picked from commit 6ff5471)

Co-authored-by: Victor Stinner [email protected]

…96869) (pythonGH-96941)

At Python exit, sometimes a thread holding the GIL can wait forever
for a thread (usually a daemon thread) which requested to drop the
GIL, whereas the thread already exited. To fix the race condition,
the thread which requested the GIL drop now resets its request before
exiting.

take_gil() now calls RESET_GIL_DROP_REQUEST() before
PyThread_exit_thread() if it called SET_GIL_DROP_REQUEST to fix a
race condition with drop_gil().

Issue discovered and analyzed by Mingliang ZHAO.

(cherry picked from commit 04f4977)
(cherry picked from commit 6ff5471)

Co-authored-by: Victor Stinner <[email protected]>
Copy link
Member

@vstinner vstinner left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM, good bot

@miss-islington
Copy link
Contributor Author

Status check is done, and it's a success ✅.

@miss-islington miss-islington merged commit dcff50a into python:3.10 Sep 20, 2022
@miss-islington miss-islington deleted the backport-6ff5471-3.10 branch September 20, 2022 00:37
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

3 participants