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8232747: Shenandoah: Concurrent GC should deactivate SATB before processing weak roots

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Reviewed-by: shade
This commit is contained in:
Zhengyu Gu 2019-10-22 11:59:42 -04:00
parent 02dc957198
commit 094a1b8a5f
4 changed files with 12 additions and 21 deletions
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2
src/hotspot/share/gc/shenandoah/shenandoahConcurrentMark.cpp
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@ -442,8 +442,6 @@ void ShenandoahConcurrentMark::finish_mark_from_roots(bool full_gc) {
weak_refs_work(full_gc);
}
_heap->parallel_cleaning(full_gc);
assert(task_queues()->is_empty(), "Should be empty");
TASKQUEUE_STATS_ONLY(task_queues()->print_taskqueue_stats());
TASKQUEUE_STATS_ONLY(task_queues()->reset_taskqueue_stats());

25
src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
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@ -1478,6 +1478,12 @@ void ShenandoahHeap::op_final_mark() {
if (!cancelled_gc()) {
concurrent_mark()->finish_mark_from_roots(/* full_gc = */ false);
// Marking is completed, deactivate SATB barrier
set_concurrent_mark_in_progress(false);
mark_complete_marking_context();
parallel_cleaning(false /* full gc*/);
if (has_forwarded_objects()) {
// Degen may be caused by failed evacuation of roots
if (is_degenerated_gc_in_progress()) {
@ -1485,14 +1491,12 @@ void ShenandoahHeap::op_final_mark() {
} else {
concurrent_mark()->update_thread_roots(ShenandoahPhaseTimings::update_roots);
}
set_has_forwarded_objects(false);
}
if (ShenandoahVerify) {
verifier()->verify_roots_no_forwarded();
}
stop_concurrent_marking();
// All allocations past TAMS are implicitly live, adjust the region data.
// Bitmaps/TAMS are swapped at this point, so we need to poll complete bitmap.
{
@ -1575,8 +1579,10 @@ void ShenandoahHeap::op_final_mark() {
}
} else {
// If this cycle was updating references, we need to keep the has_forwarded_objects
// flag on, for subsequent phases to deal with it.
concurrent_mark()->cancel();
stop_concurrent_marking();
set_concurrent_mark_in_progress(false);
if (process_references()) {
// Abandon reference processing right away: pre-cleaning must have failed.
@ -1872,17 +1878,6 @@ void ShenandoahHeap::op_degenerated_futile() {
op_full(GCCause::_shenandoah_upgrade_to_full_gc);
}
void ShenandoahHeap::stop_concurrent_marking() {
assert(is_concurrent_mark_in_progress(), "How else could we get here?");
set_concurrent_mark_in_progress(false);
if (!cancelled_gc()) {
// If we needed to update refs, and concurrent marking has been cancelled,
// we need to finish updating references.
set_has_forwarded_objects(false);
mark_complete_marking_context();
}
}
void ShenandoahHeap::force_satb_flush_all_threads() {
if (!is_concurrent_mark_in_progress() && !is_concurrent_traversal_in_progress()) {
// No need to flush SATBs

2
src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp
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@ -717,8 +717,6 @@ public:
void deduplicate_string(oop str);
void stop_concurrent_marking();
private:
void trash_cset_regions();
void update_heap_references(bool concurrent);

4
src/hotspot/share/gc/shenandoah/shenandoahMarkCompact.cpp
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@ -110,7 +110,7 @@ void ShenandoahMarkCompact::do_it(GCCause::Cause gc_cause) {
// b. Cancel concurrent mark, if in progress
if (heap->is_concurrent_mark_in_progress()) {
heap->concurrent_mark()->cancel();
heap->stop_concurrent_marking();
heap->set_concurrent_mark_in_progress(false);
}
assert(!heap->is_concurrent_mark_in_progress(), "sanity");
@ -243,8 +243,8 @@ void ShenandoahMarkCompact::phase1_mark_heap() {
cm->update_roots(ShenandoahPhaseTimings::full_gc_roots);
cm->mark_roots(ShenandoahPhaseTimings::full_gc_roots);
cm->finish_mark_from_roots(/* full_gc = */ true);
heap->mark_complete_marking_context();
heap->parallel_cleaning(true /* full_gc */);
}
class ShenandoahPrepareForCompactionObjectClosure : public ObjectClosure {