Fixes a race condition in Config Admin shutdown#1043
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tcormackMW merged 4 commits intodevelopmentfrom Oct 9, 2024
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September 30, 2024 17:09
tcormackMW
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Oct 2, 2024
Codecov ReportAttention: Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## development #1043 +/- ##
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- Coverage 88.42% 88.40% -0.03%
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Files 252 252
Lines 12155 12165 +10
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+ Hits 10748 10754 +6
- Misses 1407 1411 +4
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jeffdiclemente
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Oct 9, 2024
jeffdiclemente
approved these changes
Oct 9, 2024
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In the current implementation, the ConfigurationAdminImpl object is being destroyed from a thread posted to the AsyncWorkService. This occurs because the ConfigurationListenerImpl holds the last reference to configAdmin. When ConfigurationListenerImpl completes its task of notifying listeners, it releases its reference, triggering the destruction of configAdminImpl. During its destruction, configAdminImpl waits for all its posted tasks to complete, including the NotifyConfigurationUpdated tasks in the AsyncWorkService (which this thread itself is), leading to a deadlock as these tasks can never complete.
Solution
To resolve this issue, I modified the Activator::Stop method for ConfigAdminImpl. Instead of setting configAdminImpl to nullptr immediately after unregistering, ensure that configAdminImpl stops posting new asynchronous work and waits for all existing tasks to complete. This ensures that ConfigurationListenerImpl does not hold the last reference to configAdmin, preventing its premature destruction and avoiding the deadlock
Test Case:
Before change: deadlocks roughly every 1/300 runs
After change: didn't deadlock after 120,000 runs