common/lru: fix race in lru (#26164) #16
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
This fixes a problem in the SizeConstrainedLRU. The SCLRU uses an underlying simple lru which is not thread safe. During the Get operation, the recentness of the accessed item is updated, so it is not a pure read-operation. Therefore, the mutex we need is a full mutex, not RLock. This PR changes the mutex to be a regular Mutex, instead of RWMutex, so a reviewer can at a glance see that all affected locations are fixed. (cherry picked from commit 8334b5f)
dindinw
approved these changes
Nov 19, 2022
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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Outdated suggestions cannot be applied.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.
This fixes a problem in the SizeConstrainedLRU. The SCLRU uses an underlying simple lru which is not thread safe. During the Get operation, the recentness of the accessed item is updated, so it is not a pure read-operation. Therefore, the mutex we need is a full mutex, not RLock.
This PR changes the mutex to be a regular Mutex, instead of RWMutex, so a reviewer can at a glance see that all affected locations are fixed.
(cherry picked from commit 8334b5f)