Fix Notifications.close() deadlock#13
Merged
merlimat merged 3 commits intooxia-db:mainfrom Apr 16, 2026
Merged
Conversation
close() was joining worker threads while holding self._lock. Workers acquire the same lock to update _last_notification after each batch, so if close() catches a worker mid-update both sides wait on each other indefinitely. Fix: cancel streams under the lock (so no new batches arrive), then release the lock before joining. Includes a regression test that reproduces the deadlock by having the worker cycle through the lock hundreds of times during close(). Signed-off-by: Matteo Merli <mmerli@apache.org>
Signed-off-by: Matteo Merli <mmerli@apache.org> # Conflicts: # src/oxia/internal/notifications.py
The reconnect test belongs in PR oxia-db#14 (bug oxia-db#1) which rewrites the Notifications class. This PR only fixes the close() deadlock. Signed-off-by: Matteo Merli <mmerli@apache.org>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
close() joined worker threads while holding self._lock. Workers acquire the same lock to update _last_notification after each batch — if close() catches a worker mid-update, both sides wait on each other.
Fix: cancel streams under the lock, then release before joining.
Includes regression test with a high-throughput fake stream that reproduces the deadlock.