Fix race in index delegate callback #110
Merged
Conversation
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
TSan does not support sysv semaphores, so switch to posix mutex. Also, disable robust mutexes, since we do not support multi-process access to the database anyway.
All calls to `processingCompleted` are called from the unit processing queue, but `processingAddedPending` can be called from other queues, including an arbitrary queue in the case of `addUnitOutFilePaths` and `removeUnitOutFilePaths`. The result is that if there is a session being processed, we might increment and decrement `PendingActions` concurrently. We obsevered an assertion failure where `NumActions` was greater than `NumActions`, which was likely caused by this race. rdar://68024910
|
@swift-ci please test |
akyrtzi
approved these changes
Sep 1, 2020
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Outdated suggestions cannot be applied.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.
All calls to
processingCompletedare called from the unit processing queue, butprocessingAddedPendingcan be called from other queues, including an arbitrary queue in the case ofaddUnitOutFilePathsandremoveUnitOutFilePaths.The result is that if there is a session being processed, we might increment and decrement
PendingActionsconcurrently. We obsevered an assertion failure whereNumActionswas greater thanNumActions, which was likely caused by this race.rdar://68024910
Also, switch to posix mutex in lmdb. TSan does not support sysv semaphores, so switch to posix mutex. Also,
disable robust mutexes, since we do not support multi-process access to the database anyway.