8232232: G1RemSetSummary::_rs_threads_vtimes is not initialized to zero

Fix error in "Concurrent refinement threads times" in GC log and cleanup.

Reviewed-by: tschatzl, kbarrett

Author: Man Cao

src/hotspot/share/gc/g1/g1RemSet.cpp

@@ -487,7 +487,7 @@ G1RemSet::G1RemSet(G1CollectedHeap* g1h,
                    G1CardTable* ct,
                    G1HotCardCache* hot_card_cache) :
   _scan_state(new G1RemSetScanState()),
-  _prev_period_summary(),
+  _prev_period_summary(false),
   _g1h(g1h),
   _ct(ct),
   _g1p(_g1h->policy()),
@@ -1404,7 +1404,7 @@ void G1RemSet::print_periodic_summary_info(const char* header, uint period_count
   if ((G1SummarizeRSetStatsPeriod > 0) && log_is_enabled(Trace, gc, remset) &&
       (period_count % G1SummarizeRSetStatsPeriod == 0)) {
 
-    G1RemSetSummary current(this);
+    G1RemSetSummary current;
     _prev_period_summary.subtract_from(&current);
 
     Log(gc, remset) log;
@@ -1421,7 +1421,7 @@ void G1RemSet::print_summary_info() {
   Log(gc, remset, exit) log;
   if (log.is_trace()) {
     log.trace(" Cumulative RS summary");
-    G1RemSetSummary current(this);
+    G1RemSetSummary current;
     ResourceMark rm;
     LogStream ls(log.trace());
     current.print_on(&ls);

src/hotspot/share/gc/g1/g1RemSetSummary.cpp

@@ -81,8 +81,7 @@ double G1RemSetSummary::rs_thread_vtime(uint thread) const {
   return _rs_threads_vtimes[thread];
 }
 
-G1RemSetSummary::G1RemSetSummary() :
-  _rem_set(NULL),
+G1RemSetSummary::G1RemSetSummary(bool should_update) :
   _total_mutator_refined_cards(0),
   _total_concurrent_refined_cards(0),
   _num_coarsenings(0),
@@ -91,17 +90,10 @@ G1RemSetSummary::G1RemSetSummary() :
   _sampling_thread_vtime(0.0f) {
 
   memset(_rs_threads_vtimes, 0, sizeof(double) * _num_vtimes);
-}
 
-G1RemSetSummary::G1RemSetSummary(G1RemSet* rem_set) :
-  _rem_set(rem_set),
-  _total_mutator_refined_cards(0),
-  _total_concurrent_refined_cards(0),
-  _num_coarsenings(0),
-  _num_vtimes(G1ConcurrentRefine::max_num_threads()),
-  _rs_threads_vtimes(NEW_C_HEAP_ARRAY(double, _num_vtimes, mtGC)),
-  _sampling_thread_vtime(0.0f) {
-  update();
+  if (should_update) {
+    update();
+  }
 }
 
 G1RemSetSummary::~G1RemSetSummary() {

src/hotspot/share/gc/g1/g1RemSetSummary.hpp

@@ -36,8 +36,6 @@ class G1RemSetSummary {
 private:
   friend class GetRSThreadVTimeClosure;
 
-  G1RemSet* _rem_set;
-
   size_t _total_mutator_refined_cards;
   size_t _total_concurrent_refined_cards;
 
@@ -57,8 +55,7 @@ class G1RemSetSummary {
   void update();
 
 public:
-  G1RemSetSummary();
-  G1RemSetSummary(G1RemSet* remset);
+  G1RemSetSummary(bool should_update = true);
 
   ~G1RemSetSummary();