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Outdated suggestions cannot be applied.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.
After trying for quite a while to find the source of some hard-to-reproduce fuzz bugs, this PR seems the best fix. While I was unable to find the exact cause, commit 8b30a36 did indeed trigger threadsanitizer, so it seemed the semaphores sometimes work in ways I do not understand.
Mutexes, while needing more syscalls, are easier to comprehend. While I haven't yet run local fuzzing for long enough to be able to assume the bug has been fixed, I am creating this PR to run CI and CI-Fuzz.