8302312: Make ParGCRareEvent_lock G1 specific

Reviewed-by: sjohanss, kbarrett

Author: Thomas Schatzl

src/hotspot/share/gc/g1/g1ConcurrentMark.cpp

@@ -1398,7 +1398,7 @@ class G1ReclaimEmptyRegionsTask : public WorkerTask {
                                    cl.archive_regions_removed(),
                                    cl.humongous_regions_removed());
     {
-      MutexLocker x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+      MutexLocker x(G1RareEvent_lock, Mutex::_no_safepoint_check_flag);
       _g1h->decrement_summary_bytes(cl.freed_bytes());
 
       _cleanup_list->add_ordered(&local_cleanup_list);

src/hotspot/share/gc/g1/g1OopClosures.inline.hpp

@@ -291,7 +291,7 @@ inline void G1VerifyLiveClosure::do_oop_work(T* p) {
   bool is_in_heap = _g1h->is_in(obj);
 
   if (!is_in_heap || _g1h->is_obj_dead_cond(obj, _vo)) {
-    MutexLocker x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+    MutexLocker x(G1RareEvent_lock, Mutex::_no_safepoint_check_flag);
 
     if (!has_failures()) {
       log.error("----------");

src/hotspot/share/gc/g1/g1YoungCollector.cpp

@@ -424,7 +424,7 @@ class G1PrepareEvacuationTask : public WorkerTask {
     G1PrepareRegionsClosure cl(_g1h, this);
     _g1h->heap_region_par_iterate_from_worker_offset(&cl, &_claimer, worker_id);
 
-    MutexLocker x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+    MutexLocker x(G1RareEvent_lock, Mutex::_no_safepoint_check_flag);
     _all_card_set_stats.add(cl.card_set_stats());
   }
 

src/hotspot/share/gc/g1/heapRegion.cpp

@@ -496,7 +496,7 @@ class VerifyRemSetClosure : public G1VerificationClosure {
         Log(gc, verify) log;
         LogStream ls(log.error());
 
-        MutexLocker x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+        MutexLocker x(G1RareEvent_lock, Mutex::_no_safepoint_check_flag);
 
         if (!has_failures()) {
           log.error("----------");

src/hotspot/share/runtime/mutexLocker.cpp

@@ -78,11 +78,11 @@ Mutex*   NonJavaThreadsListSync_lock  = nullptr;
 Monitor* CGC_lock                     = nullptr;
 Monitor* STS_lock                     = nullptr;
 Monitor* G1OldGCCount_lock            = nullptr;
+Mutex*   G1RareEvent_lock             = nullptr;
 Mutex*   G1DetachedRefinementStats_lock = nullptr;
 Mutex*   MarkStackFreeList_lock       = nullptr;
 Mutex*   MarkStackChunkList_lock      = nullptr;
 Mutex*   MonitoringSupport_lock       = nullptr;
-Mutex*   ParGCRareEvent_lock          = nullptr;
 Monitor* ConcurrentGCBreakpoints_lock = nullptr;
 Mutex*   Compile_lock                 = nullptr;
 Monitor* MethodCompileQueue_lock      = nullptr;
@@ -359,7 +359,7 @@ void mutex_init() {
 
   if (UseG1GC) {
     defl(G1OldGCCount_lock         , PaddedMonitor, Threads_lock, true);
-    defl(ParGCRareEvent_lock       , PaddedMutex  , Threads_lock, true);
+    defl(G1RareEvent_lock          , PaddedMutex  , Threads_lock, true);
   }
 
   defl(CompileTaskAlloc_lock       , PaddedMutex ,  MethodCompileQueue_lock);

src/hotspot/share/runtime/mutexLocker.hpp

@@ -69,11 +69,11 @@ extern Monitor* CGC_lock;                        // used for coordination betwee
                                                  // fore- & background GC threads.
 extern Monitor* STS_lock;                        // used for joining/leaving SuspendibleThreadSet.
 extern Monitor* G1OldGCCount_lock;               // in support of "concurrent" full gc
+extern Mutex*   G1RareEvent_lock;                // Synchronizes (rare) parallel GC operations.
 extern Mutex*   G1DetachedRefinementStats_lock;  // Lock protecting detached refinement stats
 extern Mutex*   MarkStackFreeList_lock;          // Protects access to the global mark stack free list.
 extern Mutex*   MarkStackChunkList_lock;         // Protects access to the global mark stack chunk list.
 extern Mutex*   MonitoringSupport_lock;          // Protects updates to the serviceability memory pools.
-extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.
 extern Monitor* ConcurrentGCBreakpoints_lock;    // Protects concurrent GC breakpoint management
 extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
 extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued