Precise GC time measurements.

src/heap.h

 // Copyright 2012 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 1578 matching lines @@
 
   // Returns the size of objects residing in non new spaces.
   intptr_t PromotedSpaceSizeOfObjects();
 
   double total_regexp_code_generated() { return total_regexp_code_generated_; }
   void IncreaseTotalRegexpCodeGenerated(int size) {
     total_regexp_code_generated_ += size;
   }
 
   // Returns maximum GC pause.
-  int get_max_gc_pause() { return max_gc_pause_; }
+  float get_max_gc_pause() { return max_gc_pause_; }
 
   // Returns maximum size of objects alive after GC.
   intptr_t get_max_alive_after_gc() { return max_alive_after_gc_; }
 
   // Returns minimal interval between two subsequent collections.
   int get_min_in_mutator() { return min_in_mutator_; }
 
   // TODO(hpayer): remove, should be handled by GCTracer
   void AddMarkingTime(double marking_time) {
     marking_time_ += marking_time;
@@ skipping 567 matching lines @@
   static const int kInitialEvalCacheSize = 64;
   static const int kInitialNumberStringCacheSize = 256;
 
   // Object counts and used memory by InstanceType
   size_t object_counts_[OBJECT_STATS_COUNT];
   size_t object_counts_last_time_[OBJECT_STATS_COUNT];
   size_t object_sizes_[OBJECT_STATS_COUNT];
   size_t object_sizes_last_time_[OBJECT_STATS_COUNT];
 
   // Maximum GC pause.
-  int max_gc_pause_;
+  float max_gc_pause_;

[Michael Starzinger, 2013/02/11 15:56:31]

IMHO, this should actually use double precision as all the other floating-point
millisecond-based timing counters use that as well.

 
   // Total time spent in GC.
   int total_gc_time_ms_;
 
   // Maximum size of objects alive after GC.
   intptr_t max_alive_after_gc_;
 
   // Minimal interval between two subsequent collections.
   int min_in_mutator_;
 
@@ skipping 747 matching lines @@
   AssertNoAllocation no_alloc;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_