Need writeBarrier between resetting the state and freeContinuation

For weak memory ordering system such as PowerPC, we need to writeBarrier between resetting the state of continuation(set the state to unmounted) and freeing continuation/postUnmountContinuation during continuation unmounting to avoid potential assert/issue caused by inconsist state (in case the instructions are reordered). Signed-off-by: hulin <[email protected]>
eclipse-openj9 · Dec 6, 2023 · 9fdaede · 9fdaede
1 parent d5dea53
commit 9fdaede
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/runtime/vm/ContinuationHelpers.cpp b/runtime/vm/ContinuationHelpers.cpp
@@ -306,6 +306,7 @@ yieldContinuation(J9VMThread *currentThread, BOOLEAN isFinished)
 	 */
 	Assert_VM_true(VM_ContinuationHelpers::isMountedWithCarrierThread(*continuationStatePtr, currentThread));
 	VM_ContinuationHelpers::resetCarrierID(continuationStatePtr);
+	VM_AtomicSupport::writeBarrier();
 	/* Logically postUnmountContinuation(), which add the related continuation Object to the rememberedSet or dirty the Card for concurrent marking for future scanning, should be called
 	 * before resetCarrierID(), but the scan might happened before resetCarrierID() if concurrent card clean happens, then the related compensating scan might be
 	 * missed due to the continuation still is stated as mounted(we don't scan any mounted continuation, it should be scanned during root scanning via J9VMThread->currentContinuation).