# HG changeset patch # User zgu # Date 1569239112 14400 # Node ID 501df37ce76bc5008b86ecbf4e5efd5098923334 # Parent 577e17cab93fdb9f19af0e93dd7ed9659f8b3fd7 8231293: Shenandoah: Traversal should not revive dead weak roots Reviewed-by: shade diff -r 577e17cab93f -r 501df37ce76b src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp --- a/src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp Mon Sep 23 12:32:13 2019 +0200 +++ b/src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp Mon Sep 23 07:45:12 2019 -0400 @@ -266,9 +266,19 @@ return NULL; } - if (_heap->is_evacuation_in_progress() && - !_heap->complete_marking_context()->is_marked(obj)) { - return NULL; + ShenandoahMarkingContext* const marking_context = _heap->marking_context(); + + if (_heap->is_evacuation_in_progress()) { + // Normal GC + if (!marking_context->is_marked(obj)) { + return NULL; + } + } else if (_heap->is_concurrent_traversal_in_progress()) { + // Traversal GC + if (marking_context->is_complete() && + !marking_context->is_marked(resolve_forwarded_not_null(obj))) { + return NULL; + } } return load_reference_barrier_not_null(obj); diff -r 577e17cab93f -r 501df37ce76b src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.cpp --- a/src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.cpp Mon Sep 23 12:32:13 2019 +0200 +++ b/src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.cpp Mon Sep 23 07:45:12 2019 -0400 @@ -594,11 +594,6 @@ } if (!_heap->cancelled_gc()) { - fixup_roots(); - _heap->parallel_cleaning(false); - } - - if (!_heap->cancelled_gc()) { assert(_task_queues->is_empty(), "queues must be empty after traversal GC"); TASKQUEUE_STATS_ONLY(_task_queues->print_taskqueue_stats()); TASKQUEUE_STATS_ONLY(_task_queues->reset_taskqueue_stats()); @@ -606,6 +601,9 @@ // No more marking expected _heap->mark_complete_marking_context(); + fixup_roots(); + _heap->parallel_cleaning(false); + // Resize metaspace MetaspaceGC::compute_new_size();