Fix races occuring when two threads expand variables at the same time #737
Conversation
This file contains 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
The `PluginLoader` class is used as an interace implemented by all kinds of repositories: of profile plugins, functions, monitors. While these are all technically "plug-in", the naming is confusing. The commit also updates the `load_all_plugins` method of the class (now `load_all_classes`) to use the class loader parameters (prefix, namespace) instead of hardcoded ones.
Previously, the parser state would be shared, creating races when two threads would attempt to expand functions in strings at the same time (e.g., when a device was hotplugged during TuneD initialization). The change requires minor refactoring: the function `Repository` class is now the one providing the expansion API to the `Variables` class instead of the original `Functions` class (now renamed to `Parser` and newly created for each expansion). Resolves: RHEL-75773
|
Thank you for the PR, Pavol, much appreciated! The basic tests with NTO on OCP with this change pass. I'm currently running a test that's trying to reproduce the original issue. I had success reproducing the issue with the old code without this fix. So far, I wasn't able to reproduce the issue with the new code. I want to test this fix at least over night. I'll report tomorrow morning how it went. |
|
No race found with overnight testing. @yarda , it would be great to have this in FDP 25.A. |
|
Thanks for the thorough testing, @jmencak! |
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Outdated suggestions cannot be applied.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.
While fixing this, I got confused by the naming of the
PluginLoaderclass. In the first commit, I propose to rename it toClassLoader, and fix one of its methods so that it truly behaves like an abstract class.For the race fix itself, see the second commit.
Resolves: RHEL-75773