zebra: avoid a race during FPM dplane plugin shutdown #17504
Merged
Conversation
This file contains 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
During zebra shutdown, the main pthread and the FPM pthread can deadlock if the FPM pthread is in fpm_reconnect(). Each pthread tries to use event_cancel_async() to cancel tasks that may be scheduled for the other pthread - this leads to a deadlock as neither thread can progress. This adds an atomic boolean that's managed as each pthread enters and leaves the cleanup code in question, preventing the two threads from running into the deadlock. Signed-off-by: Mark Stapp <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
During zebra shutdown, the main pthread in fpm_nl_finish_early() and the FPM pthread can deadlock if the FPM pthread is in fpm_reconnect(). Each pthread tries to use event_cancel_async() to cancel tasks that may be scheduled for the other pthread - this leads to deadlock as neither thread can progress.
This adds an atomic boolean that's managed as each pthread enters and leaves the cleanup code in question, preventing the two threads from running into the deadlock.