8261504: Shenandoah: reconsider ShenandoahJavaThreadsIterator::claim memory ordering

shipilev · shipilev · commit df0897ea5763 · 2021-02-15T08:43:42.000Z
Reviewed-by: zgu
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahRootProcessor.cpp b/src/hotspot/share/gc/shenandoah/shenandoahRootProcessor.cpp
@@ -46,7 +46,7 @@ ShenandoahJavaThreadsIterator::ShenandoahJavaThreadsIterator(ShenandoahPhaseTimi
 }
 
 uint ShenandoahJavaThreadsIterator::claim() {
-  return Atomic::fetch_and_add(&_claimed, _stride);
+  return Atomic::fetch_and_add(&_claimed, _stride, memory_order_relaxed);
 }
 
 void ShenandoahJavaThreadsIterator::threads_do(ThreadClosure* cl, uint worker_id) {

Original file line number	Diff line number	Diff line change
`@@ -46,7 +46,7 @@ ShenandoahJavaThreadsIterator::ShenandoahJavaThreadsIterator(ShenandoahPhaseTimi`
`46`	`46`	`}`
`47`	`47`
`48`	`48`	`uint ShenandoahJavaThreadsIterator::claim() {`
`49`		`- return Atomic::fetch_and_add(&_claimed, _stride);`
	`49`	`+ return Atomic::fetch_and_add(&_claimed, _stride, memory_order_relaxed);`
`50`	`50`	`}`
`51`	`51`
`52`	`52`	`void ShenandoahJavaThreadsIterator::threads_do(ThreadClosure* cl, uint worker_id) {`