Count Mark-Compact/Mark-Sweep collections only after compaction decision was made

src/heap.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 639 matching lines @@
     ASSERT(!allocation_allowed_);
     GCTracer::Scope scope(tracer, GCTracer::Scope::EXTERNAL);
     global_gc_epilogue_callback_();
   }
   VerifySymbolTable();
 }
 
 
 void Heap::MarkCompact(GCTracer* tracer) {
   gc_state_ = MARK_COMPACT;
-  if (MarkCompactCollector::IsCompacting()) {
-    mc_count_++;
-  } else {
-    ms_count_++;
-  }
-  tracer->set_full_gc_count(mc_count_);
   LOG(ResourceEvent("markcompact", "begin"));
 
   MarkCompactCollector::Prepare(tracer);
 
   bool is_compacting = MarkCompactCollector::IsCompacting();
 
+  if (is_compacting) {
+    mc_count_++;
+  } else {
+    ms_count_++;
+  }
+  tracer->set_full_gc_count(mc_count_ + ms_count_);
+
   MarkCompactPrologue(is_compacting);
 
   MarkCompactCollector::CollectGarbage();
 
   MarkCompactEpilogue(is_compacting);
 
   LOG(ResourceEvent("markcompact", "end"));
 
   gc_state_ = NOT_IN_GC;
 
@@ skipping 3971 matching lines @@
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 List<Object*> ExternalStringTable::new_space_strings_;
 List<Object*> ExternalStringTable::old_space_strings_;
 
 } }  // namespace v8::internal