8264718: Shenandoah: enable string deduplication during root scanning

Reviewed-by: shade

Author: zhengyu123

src/hotspot/share/gc/shenandoah/shenandoahConcurrentMark.cpp

@@ -191,8 +191,13 @@ ShenandoahMarkConcurrentRootsTask::ShenandoahMarkConcurrentRootsTask(ShenandoahO
 void ShenandoahMarkConcurrentRootsTask::work(uint worker_id) {
   ShenandoahConcurrentWorkerSession worker_session(worker_id);
   ShenandoahObjToScanQueue* q = _queue_set->queue(worker_id);
-  ShenandoahMarkRefsClosure cl(q, _rp);
-  _root_scanner.roots_do(&cl, worker_id);
+  if (ShenandoahStringDedup::is_enabled()) {
+    ShenandoahMarkRefsDedupClosure cl(q, _rp);
+    _root_scanner.roots_do(&cl, worker_id);
+  } else {
+    ShenandoahMarkRefsClosure cl(q, _rp);
+    _root_scanner.roots_do(&cl, worker_id);
+  }
 }
 
 void ShenandoahConcurrentMark::mark_concurrent_roots() {

src/hotspot/share/gc/shenandoah/shenandoahMark.cpp

@@ -41,11 +41,6 @@ ShenandoahMarkRefsSuperClosure::ShenandoahMarkRefsSuperClosure(ShenandoahObjToSc
   _weak(false)
 { }
 
-ShenandoahInitMarkRootsClosure::ShenandoahInitMarkRootsClosure(ShenandoahObjToScanQueue* q) :
-  _queue(q),
-  _mark_context(ShenandoahHeap::heap()->marking_context()) {
-}
-
 ShenandoahMark::ShenandoahMark() :
   _task_queues(ShenandoahHeap::heap()->marking_context()->task_queues()) {
 }

src/hotspot/share/gc/shenandoah/shenandoahMark.hpp

@@ -31,21 +31,6 @@
 
 class ShenandoahCMDrainMarkingStackClosure;
 
-class ShenandoahInitMarkRootsClosure : public OopClosure {
-private:
-  ShenandoahObjToScanQueue* const _queue;
-  ShenandoahMarkingContext* const _mark_context;
-
-  template <class T>
-  inline void do_oop_work(T* p);
-
-public:
-  ShenandoahInitMarkRootsClosure(ShenandoahObjToScanQueue* q);
-
-  void do_oop(narrowOop* p) { do_oop_work(p); }
-  void do_oop(oop* p)       { do_oop_work(p); }
-};
-
 // Base class for mark
 // Mark class does not maintain states. Instead, mark states are
 // maintained by task queues, mark bitmap and SATB buffers (concurrent mark)

src/hotspot/share/gc/shenandoah/shenandoahMark.inline.hpp

@@ -39,11 +39,6 @@
 #include "runtime/prefetch.inline.hpp"
 #include "utilities/powerOfTwo.hpp"
 
-template <class T>
-void ShenandoahInitMarkRootsClosure::do_oop_work(T* p) {
-  ShenandoahMark::mark_through_ref<T, NO_DEDUP>(p, _queue, _mark_context, false);
-}
-
 template <class T>
 void ShenandoahMark::do_task(ShenandoahObjToScanQueue* q, T* cl, ShenandoahLiveData* live_data, ShenandoahMarkTask* task) {
   oop obj = task->obj();

src/hotspot/share/gc/shenandoah/shenandoahSTWMark.cpp

@@ -33,9 +33,38 @@
 #include "gc/shenandoah/shenandoahOopClosures.inline.hpp"
 #include "gc/shenandoah/shenandoahReferenceProcessor.hpp"
 #include "gc/shenandoah/shenandoahRootProcessor.inline.hpp"
+#include "gc/shenandoah/shenandoahStringDedup.hpp"
 #include "gc/shenandoah/shenandoahSTWMark.hpp"
 #include "gc/shenandoah/shenandoahVerifier.hpp"
 
+template <StringDedupMode STRING_DEDUP>
+class ShenandoahInitMarkRootsClosure : public OopClosure {
+private:
+  ShenandoahObjToScanQueue* const _queue;
+  ShenandoahMarkingContext* const _mark_context;
+
+  template <class T>
+  inline void do_oop_work(T* p);
+
+public:
+  ShenandoahInitMarkRootsClosure(ShenandoahObjToScanQueue* q);
+
+  void do_oop(narrowOop* p) { do_oop_work(p); }
+  void do_oop(oop* p)       { do_oop_work(p); }
+};
+
+template <StringDedupMode STRING_DEDUP>
+ShenandoahInitMarkRootsClosure<STRING_DEDUP>::ShenandoahInitMarkRootsClosure(ShenandoahObjToScanQueue* q) :
+  _queue(q),
+  _mark_context(ShenandoahHeap::heap()->marking_context()) {
+}
+
+template <StringDedupMode STRING_DEDUP>
+template <class T>
+void ShenandoahInitMarkRootsClosure<STRING_DEDUP>::do_oop_work(T* p) {
+  ShenandoahMark::mark_through_ref<T, STRING_DEDUP>(p, _queue, _mark_context, false);
+}
+
 class ShenandoahSTWMarkTask : public AbstractGangTask {
 private:
   ShenandoahSTWMark* const _mark;
@@ -99,8 +128,13 @@ void ShenandoahSTWMark::mark() {
 }
 
 void ShenandoahSTWMark::mark_roots(uint worker_id) {
-  ShenandoahInitMarkRootsClosure  init_mark(task_queues()->queue(worker_id));
-  _root_scanner.roots_do(&init_mark, worker_id);
+  if (ShenandoahStringDedup::is_enabled()) {
+    ShenandoahInitMarkRootsClosure<ENQUEUE_DEDUP> init_mark(task_queues()->queue(worker_id));
+    _root_scanner.roots_do(&init_mark, worker_id);
+  } else {
+    ShenandoahInitMarkRootsClosure<NO_DEDUP> init_mark(task_queues()->queue(worker_id));
+    _root_scanner.roots_do(&init_mark, worker_id);
+  }
 }
 
 void ShenandoahSTWMark::finish_mark(uint worker_id) {
@@ -112,4 +146,3 @@ void ShenandoahSTWMark::finish_mark(uint worker_id) {
             false, // not cancellable
             ShenandoahStringDedup::is_enabled());
 }
-