[WIP] 馃悰 Avoid deadlock on start #1689
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[APPROVALNOTIFIER] This PR is NOT APPROVED This pull-request has been approved by: fabriziopandini The full list of commands accepted by this bot can be found here.
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pkg/manager/internal.go
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| @@ -535,8 +550,11 @@ func (cm *controllerManager) engageStopProcedure(stopComplete <-chan struct{}) e | |||
| if cm.gracefulShutdownTimeout == 0 { | |||
| return nil | |||
| } | |||
| cm.mu.Lock() | |||
| defer cm.mu.Unlock() | |||
| cm.addMu.RLock() | |||
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I think this needs to be the WriteLock, because it writes to cm.stopProcedureEngaged.
Also it seems it is not allowed to call waitgroup.Add() during a running waitgroup.Wait() , if I understand the race in CI correctly. Unfortunately you get to debug the locking here now 馃檭
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If there are no objections, I would close this PR in favour of #1690 |
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/close |
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@fabriziopandini: Closed this PR. In response to this:
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This PR tries to avoid deadlock in the start sequence when
startLeaderElectionRunnables()gets stuck inwaitForCache, but the cache can't start due the webhook not yet started, and the webhook with are run instartNonLeaderElectionRunnables()can't run due to to the mutex.The implementation follow the suggestion in #1685 (comment) and:
startLeaderElectionRunnables()andstartNonLeaderElectionRunnables()and for other serve func thus allowing parallel runwaitForCacheto be executed two times concurrentlyNote. Given this is my first PR in this area, I have commented all the reasoning about locks and possible concurrency issues, looking forward for comments.