Add per-thread closeScope queue for ScopedMemoryAccess close handling#23455
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babsingh wants to merge 1 commit intoeclipse-openj9:masterfrom
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Add per-thread closeScope queue for ScopedMemoryAccess close handling#23455babsingh wants to merge 1 commit intoeclipse-openj9:masterfrom
babsingh wants to merge 1 commit intoeclipse-openj9:masterfrom
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Replace the previous global closeScope notification mechanism with a per-thread close request list. Each thread maintains a queue of J9CloseScopeListNode entries representing pending MemorySessionImpl close requests. ScopedMemoryAccess.closeScope0 now walks all threads, identifies threads accessing the session via @Scoped methods, and enqueues a close request on the target thread. Global refs to the session and error are shared across all nodes and tracked via a hidden MemorySessionImpl.closeScopeCount field. javaCheckAsyncMessages processes the queued requests, delivers the ScopedAccessError when appropriate, decrements the session counter, and releases the global refs once the last thread processes the request. This removes the VM-global closeScopeMutex / notifyCount mechanism and avoids races when multiple sessions are closed concurrently. Related: eclipse-openj9#22934 Signed-off-by: Babneet Singh <sbabneet@ca.ibm.com>
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@gacholio Requesting your review. This PR alone should resolve #22934, since the wait logic at the end of The earlier proposed test and OpenJ9 fixes are no longer required:
The JIT issue was previously tracked here: #13211 (comment). With this PR, the JIT issue is no longer observed. The failure frequency has dropped to the point that we see 0 failures in 100 runs, so it is no longer a blocker for the Java 26 release. |
gacholio
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Mar 7, 2026
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| omrthread_monitor_exit(vm->closeScopeMutex); | ||
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| closeScopeCount = J9OBJECT_I64_LOAD(currentThread, closeScopeObj, vm->closeScopeCountOffset); |
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Can this be derived from the loop above?
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The use of the mutex seems inconsistent (value here is read outside the mutex).
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Replace the previous global
closeScopenotification mechanism with aper-thread close request list. Each thread maintains a queue of
J9CloseScopeListNodeentries representing pendingMemorySessionImplclose requests.
ScopedMemoryAccess.closeScope0now walks all threads, identifiesthreads accessing the session via
@Scopedmethods, and enqueues aclose request on the target thread. Global refs to the session and
error are shared across all nodes and tracked via a hidden
MemorySessionImpl.closeScopeCountfield.javaCheckAsyncMessagesprocesses the queued requests, delivers theScopedAccessErrorwhen appropriate, decrements the session counter,and releases the global refs once the last thread processes the
request.
This removes the VM-global
closeScopeMutex/notifyCountmechanismand avoids races when multiple sessions are closed concurrently.
Related: #22934
Signed-off-by: Babneet Singh sbabneet@ca.ibm.com