core: Synchronize wait group access in blockchain#23673
Closed
piersy wants to merge 1 commit intoethereum:masterfrom
Closed
core: Synchronize wait group access in blockchain#23673piersy wants to merge 1 commit intoethereum:masterfrom
piersy wants to merge 1 commit intoethereum:masterfrom
Conversation
When using a wg Add is intended to be called before Wait, calling Add and Wait concurrently leads to data races. The blockchain calls wg.Add in many exported methods such as chain insert methods and it seems highly unlikely that they will be called by the same goroutine that calls Stop (where wg.Wait is called), so to avoid data races on shutdown the acesses to Add and Wait need to be synchronized. The solution is to lock over calls to Add and Wait. A golang issue with more details about this problem golang/go#23842
piersy
requested review from
holiman,
karalabe and
rjl493456442
as code owners
Contributor
|
A different fix is to remove the silly waitgroups: #22853 . If you're looking into these things, I'd appreciate if you take a look at that PR, if it seems ok to you. |
Contributor
|
I strongly prefer #22853 over this PR. |
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
When using a wg Add is intended to be called before Wait, calling Add
and Wait concurrently leads to data races.
See a simple example of this problem here:
golang/go#23842
The blockchain calls wg.Add in many exported methods such as chain
insert methods and it seems highly unlikely that they will be called by
the same goroutine that calls Stop (where wg.Wait is called), so to
avoid data races on shutdown the acesses to Add and Wait need to be
synchronized.
The solution here is to lock over calls to Add and Wait.