fix: avoid data race when setting memdb footprint hook#621
Merged
sticnarf merged 3 commits intotikv:masterfrom Nov 24, 2022
Merged
fix: avoid data race when setting memdb footprint hook#621sticnarf merged 3 commits intotikv:masterfrom
sticnarf merged 3 commits intotikv:masterfrom
Conversation
12 tasks
Collaborator
|
/cc @sticnarf |
Collaborator
|
How does it avoid the race? Will the read at |
Signed-off-by: ekexium <eke@fastmail.com>
21fe69b to
3bdebcf
Compare
Contributor
Author
Well I have no idea how it works :(. But the race test passes. Maybe use CAS instead? |
sticnarf
reviewed
Nov 23, 2022
internal/unionstore/memdb.go
Outdated
| db.allocator.memChangeHook = innerHook | ||
| db.vlog.memChangeHook = innerHook | ||
| atomic.CompareAndSwapPointer((*unsafe.Pointer)(unsafe.Pointer(&db.allocator.memChangeHook)), nil, unsafe.Pointer(&innerHook)) | ||
| atomic.CompareAndSwapPointer((*unsafe.Pointer)(unsafe.Pointer(&db.vlog.memChangeHook)), nil, unsafe.Pointer(&innerHook)) |
Collaborator
There was a problem hiding this comment.
Should we skip the second CAS if the first fails? Then, we won't assign different hooks for allocator and vlog.
Contributor
Author
There was a problem hiding this comment.
Sure we can but I think it unnecessary. By design they are always set together.
Signed-off-by: ekexium <eke@fastmail.com>
sticnarf
approved these changes
Nov 24, 2022
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
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
No description provided.