Signal handlers use atomics #715
Merged
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
…nix signal handler The variable my_sig_num_ was the only place where getSigNum was ever called and the value of the variable was never used after that. Both the variable and the function have been removed. The unix signal handler code no longer uses a mutex and instead uses a std::atomic to denote if an external user has requested that the framework stop processing events.
…own request To be properly thread safe under C++11 we switched from using a volatile bool to a volatile std::atomic<bool> as the way to communicate an external shutdown request. The mutex usr2_lock was also removed since it actually was never used correctly anyway and the std::atomic does the work the mutex should have been used for. The function getSigNum() and its related global variables were removed since the function is no longer used anywhere.
Since the variable shutdown_flag is not being used to synchronize other variables we can use the memory_order_relaxed which requires less synchronization between CPUs.
|
+1 |
|
This pull request is fully signed and it will be integrated in one of the next IBs unless changes or unless it breaks tests. |
|
Hi, I ran the tests on top of CMSSW_7_0_X_2013-09-04-0200, all tests passed: you can see the artifacts here: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/386 |
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Outdated suggestions cannot be applied.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.
Changed the unix signal handler used to allow an external user to tell cmsRun to stop processing. The signal handler used to use a mutex but now uses an std::atomic.
Removed some obsolete code which was related to the signal handler.