v8: make GCTracer persistent.

src/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/once.h"
 #include "src/base/utils/random-number-generator.h"
@@ skipping 81 matching lines @@
 #ifdef DEBUG
       allocation_timeout_(0),
 #endif  // DEBUG
       old_generation_allocation_limit_(kMinimumOldGenerationAllocationLimit),
       old_gen_exhausted_(false),
       inline_allocation_disabled_(false),
       store_buffer_rebuilder_(store_buffer()),
       hidden_string_(NULL),
       gc_safe_size_of_old_object_(NULL),
       total_regexp_code_generated_(0),
-      tracer_(NULL),
+      tracer_(this),
       high_survival_rate_period_length_(0),
       promoted_objects_size_(0),
       promotion_rate_(0),
       semi_space_copied_object_size_(0),
       semi_space_copied_rate_(0),
       maximum_size_scavenges_(0),
       max_gc_pause_(0.0),
       total_gc_time_ms_(0.0),
       max_alive_after_gc_(0),
       min_in_mutator_(kMaxInt),
@@ skipping 714 matching lines @@
       if (FLAG_trace_incremental_marking) {
         PrintF("[IncrementalMarking] Delaying MarkSweep.\n");
       }
       collector = SCAVENGER;
       collector_reason = "incremental marking delaying mark-sweep";
     }
   }
 
   bool next_gc_likely_to_collect_more = false;
 
-  { GCTracer tracer(this, gc_reason, collector_reason);
+  { tracer()->start(gc_reason, collector_reason);
     ASSERT(AllowHeapAllocation::IsAllowed());
     DisallowHeapAllocation no_allocation_during_gc;
     GarbageCollectionPrologue();
     // The GC count was incremented in the prologue.  Tell the tracer about
     // it.
-    tracer.set_gc_count(gc_count_);
+    tracer()->set_gc_count(gc_count_);
 
     // Tell the tracer which collector we've selected.
-    tracer.set_collector(collector);
+    tracer()->set_collector(collector);
 
     {
       HistogramTimerScope histogram_timer_scope(
           (collector == SCAVENGER) ? isolate_->counters()->gc_scavenger()
                                    : isolate_->counters()->gc_compactor());
       next_gc_likely_to_collect_more =
-          PerformGarbageCollection(collector, &tracer, gc_callback_flags);
+          PerformGarbageCollection(collector, gc_callback_flags);
     }
 
     GarbageCollectionEpilogue();
+    tracer()->stop();
   }
 
   // Start incremental marking for the next cycle. The heap snapshot
   // generator needs incremental marking to stay off after it aborted.
   if (!mark_compact_collector()->abort_incremental_marking() &&
       incremental_marking()->IsStopped() &&
       incremental_marking()->WorthActivating() &&
       NextGCIsLikelyToBeFull()) {
     incremental_marking()->Start();
   }
@@ skipping 181 matching lines @@
 
   if (survival_rate > kYoungSurvivalRateHighThreshold) {
     high_survival_rate_period_length_++;
   } else {
     high_survival_rate_period_length_ = 0;
   }
 }
 
 bool Heap::PerformGarbageCollection(
     GarbageCollector collector,
-    GCTracer* tracer,
     const v8::GCCallbackFlags gc_callback_flags) {
   int freed_global_handles = 0;
 
   if (collector != SCAVENGER) {
     PROFILE(isolate_, CodeMovingGCEvent());
   }
 
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) {
     VerifyStringTable(this);
   }
 #endif
 
   GCType gc_type =
       collector == MARK_COMPACTOR ? kGCTypeMarkSweepCompact : kGCTypeScavenge;
 
   { GCCallbacksScope scope(this);
     if (scope.CheckReenter()) {
       AllowHeapAllocation allow_allocation;
-      GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL);
+      GCTracer::Scope scope(tracer(), GCTracer::Scope::EXTERNAL);
       VMState<EXTERNAL> state(isolate_);
       HandleScope handle_scope(isolate_);
       CallGCPrologueCallbacks(gc_type, kNoGCCallbackFlags);
     }
   }
 
   EnsureFromSpaceIsCommitted();
 
   int start_new_space_size = Heap::new_space()->SizeAsInt();
 
   if (IsHighSurvivalRate()) {
     // We speed up the incremental marker if it is running so that it
     // does not fall behind the rate of promotion, which would cause a
     // constantly growing old space.
     incremental_marking()->NotifyOfHighPromotionRate();
   }
 
   if (collector == MARK_COMPACTOR) {
     // Perform mark-sweep with optional compaction.
-    MarkCompact(tracer);
+    MarkCompact();
     sweep_generation_++;
     // Temporarily set the limit for case when PostGarbageCollectionProcessing
     // allocates and triggers GC. The real limit is set at after
     // PostGarbageCollectionProcessing.
     old_generation_allocation_limit_ =
         OldGenerationAllocationLimit(PromotedSpaceSizeOfObjects(), 0);
     old_gen_exhausted_ = false;
   } else {
-    tracer_ = tracer;
     Scavenge();
-    tracer_ = NULL;
   }
 
   UpdateSurvivalStatistics(start_new_space_size);
 
   isolate_->counters()->objs_since_last_young()->Set(0);
 
   // Callbacks that fire after this point might trigger nested GCs and
   // restart incremental marking, the assertion can't be moved down.
   ASSERT(collector == SCAVENGER || incremental_marking()->IsStopped());
 
   gc_post_processing_depth_++;
   { AllowHeapAllocation allow_allocation;
-    GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL);
+    GCTracer::Scope scope(tracer(), GCTracer::Scope::EXTERNAL);
     freed_global_handles =
         isolate_->global_handles()->PostGarbageCollectionProcessing(
-            collector, tracer);
+            collector);
   }
   gc_post_processing_depth_--;
 
   isolate_->eternal_handles()->PostGarbageCollectionProcessing(this);
 
   // Update relocatables.
   Relocatable::PostGarbageCollectionProcessing(isolate_);
 
   if (collector == MARK_COMPACTOR) {
     // Register the amount of external allocated memory.
     amount_of_external_allocated_memory_at_last_global_gc_ =
         amount_of_external_allocated_memory_;
     old_generation_allocation_limit_ =
         OldGenerationAllocationLimit(PromotedSpaceSizeOfObjects(),
                                      freed_global_handles);
   }
 
   { GCCallbacksScope scope(this);
     if (scope.CheckReenter()) {
       AllowHeapAllocation allow_allocation;
-      GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL);
+      GCTracer::Scope scope(tracer(), GCTracer::Scope::EXTERNAL);
       VMState<EXTERNAL> state(isolate_);
       HandleScope handle_scope(isolate_);
       CallGCEpilogueCallbacks(gc_type, gc_callback_flags);
     }
   }
 
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) {
     VerifyStringTable(this);
   }
@@ skipping 32 matching lines @@
       } else {
         v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate());
         gc_epilogue_callbacks_[i].callback(
             isolate, gc_type, gc_callback_flags);
       }
     }
   }
 }
 
 
-void Heap::MarkCompact(GCTracer* tracer) {
+void Heap::MarkCompact() {
   gc_state_ = MARK_COMPACT;
   LOG(isolate_, ResourceEvent("markcompact", "begin"));
 
   uint64_t size_of_objects_before_gc = SizeOfObjects();
 
-  mark_compact_collector_.Prepare(tracer);
+  mark_compact_collector_.Prepare();
 
   ms_count_++;
-  tracer->set_full_gc_count(ms_count_);
+  tracer()->set_full_gc_count(ms_count_);
 
   MarkCompactPrologue();
 
   mark_compact_collector_.CollectGarbage();
 
   LOG(isolate_, ResourceEvent("markcompact", "end"));
 
   gc_state_ = NOT_IN_GC;
 
   isolate_->counters()->objs_since_last_full()->Set(0);
@@ skipping 4735 matching lines @@
   OldSpaces spaces(heap);
   for (OldSpace* space = spaces.next();
        space != NULL;
        space = spaces.next()) {
     holes_size += space->Waste() + space->Available();
   }
   return holes_size;
 }
 
 
-GCTracer::GCTracer(Heap* heap,
-                   const char* gc_reason,
-                   const char* collector_reason)
+GCTracer::GCTracer(Heap* heap)
     : start_time_(0.0),
       start_object_size_(0),
       start_memory_size_(0),
       gc_count_(0),
       full_gc_count_(0),
+      in_free_list_or_wasted_before_gc_(0),
       allocated_since_last_gc_(0),
       spent_in_mutator_(0),
       nodes_died_in_new_space_(0),
       nodes_copied_in_new_space_(0),
       nodes_promoted_(0),
+      steps_count_(0),
+      steps_took_(0.0),
+      longest_step_(0.0),
+      steps_count_since_last_gc_(0),
+      steps_took_since_last_gc_(0.0),
       heap_(heap),
-      gc_reason_(gc_reason),
-      collector_reason_(collector_reason) {
-  if (!FLAG_trace_gc && !FLAG_print_cumulative_gc_stat) return;
+      gc_reason_(NULL),
+      collector_reason_(NULL) {
+
+  for (int i = 0; i < Scope::kNumberOfScopes; i++) {
+    scopes_[i] = 0;
+  }
+}
+
+
+GCTracer::~GCTracer() {
+}
+
+
+void GCTracer::start(const char* gc_reason, const char* collector_reason) {
+  if (!FLAG_trace_gc && !FLAG_print_cumulative_gc_stat)
+    return;
+
+  gc_count_ = 0;
+  full_gc_count_ = 0;
+  spent_in_mutator_ = 0;
+  nodes_died_in_new_space_ = 0;
+  nodes_copied_in_new_space_ = 0;
+  nodes_promoted_ = 0;
+  gc_reason_ = gc_reason;
+  collector_reason_ = collector_reason;
+
   start_time_ = base::OS::TimeCurrentMillis();
   start_object_size_ = heap_->SizeOfObjects();
   start_memory_size_ = heap_->isolate()->memory_allocator()->Size();
 
   for (int i = 0; i < Scope::kNumberOfScopes; i++) {
     scopes_[i] = 0;
   }
 
-  in_free_list_or_wasted_before_gc_ = CountTotalHolesSize(heap);
+  in_free_list_or_wasted_before_gc_ = CountTotalHolesSize(heap_);
 
   allocated_since_last_gc_ =
       heap_->SizeOfObjects() - heap_->alive_after_last_gc_;
 
   if (heap_->last_gc_end_timestamp_ > 0) {
     spent_in_mutator_ = Max(start_time_ - heap_->last_gc_end_timestamp_, 0.0);
   }
-
-  steps_count_ = heap_->incremental_marking()->steps_count();
-  steps_took_ = heap_->incremental_marking()->steps_took();
-  longest_step_ = heap_->incremental_marking()->longest_step();
-  steps_count_since_last_gc_ =
-      heap_->incremental_marking()->steps_count_since_last_gc();
-  steps_took_since_last_gc_ =
-      heap_->incremental_marking()->steps_took_since_last_gc();
 }
 
 
-GCTracer::~GCTracer() {
+void GCTracer::stop() {
   // Printf ONE line iff flag is set.
   if (!FLAG_trace_gc && !FLAG_print_cumulative_gc_stat) return;
 
   bool first_gc = (heap_->last_gc_end_timestamp_ == 0);
 
   heap_->alive_after_last_gc_ = heap_->SizeOfObjects();
   heap_->last_gc_end_timestamp_ = base::OS::TimeCurrentMillis();
 
   double time = heap_->last_gc_end_timestamp_ - start_time_;
 
@@ skipping 396 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal