Make sure locks are added immediately after acquisition#6407
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headius merged 3 commits intojruby:jruby-9.2from Sep 22, 2020
Merged
Make sure locks are added immediately after acquisition#6407headius merged 3 commits intojruby:jruby-9.2from
headius merged 3 commits intojruby:jruby-9.2from
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There's a race doing the lock add after the executeTask, since a thread event could interrupt the flow and bypass that logic. A finally would not be appropriate, since an interrupted attempt to acquire the lock would then stil add it. Instead we just move the lock add immediately after lockInterruptibly. If we reach this point, the lock is locked by the current thread, and must be added. Fixes jruby#6405 and maybe jruby#6326.
It should never happen that there's a lock in the current-thread's list of locked locks that is not actually locked, but if so we should not allow this error to prevent unlocking the others. We warn that this is a bug and proceed to the remaining locks.
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Tracked down the regression to bea9ad4 (released in 9.2.8.0). |
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I made the unlocking at thread disposition more robust, but did not see any other risky pieces of code related to locking. We'll go with this. |
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There's a race doing the lock add after the executeTask, since a thread event could interrupt the flow and bypass that logic. A finally would not be appropriate, since an interrupted attempt to acquire the lock would then stil add it. Instead we just move the lock add immediately after lockInterruptibly. If we reach this point, the lock is locked by the current thread, and must be added.
I am looking over the rest of the lock management code in Thread to see if there's other places that could be a risk, but this appears to fix the issue reported in #6405 and probably fixes the issue in #6326.