Factor out a Histogram class from HistogramTimer, and use it to measure external fragmentation

src/v8-counters.h

-// Copyright 2011 the V8 project authors. All rights reserved.
+// 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
 //       with the distribution.
@@ skipping 31 matching lines @@
   /* Parsing timers. */                                               \
   HT(parse, V8.Parse)                                                 \
   HT(parse_lazy, V8.ParseLazy)                                        \
   HT(pre_parse, V8.PreParse)                                          \
   /* Total compilation times. */                                      \
   HT(compile, V8.Compile)                                             \
   HT(compile_eval, V8.CompileEval)                                    \
   HT(compile_lazy, V8.CompileLazy)
 
 
+#define HISTOGRAM_PERCENTAGE_LIST(HP)                                 \
+  HP(external_fragmentation_new_space,                                \
+     V8.MemoryExternalFragmentationNewSpace)                          \
+  HP(external_fragmentation_old_pointer_space,                        \
+     V8.MemoryExternalFragmentationOldPointerSpace)                   \
+  HP(external_fragmentation_old_data_space,                           \
+     V8.MemoryExternalFragmentationOldDataSpace)                      \
+  HP(external_fragmentation_code_space,                               \
+     V8.MemoryExternalFragmentationCodeSpace)                         \
+  HP(external_fragmentation_map_space,                                \
+     V8.MemoryExternalFragmentationMapSpace)                          \
+  HP(external_fragmentation_cell_space,                               \
+     V8.MemoryExternalFragmentationCellSpace)                         \
+  HP(external_fragmentation_lo_space,                                 \
+     V8.MemoryExternalFragmentationLoSpace)
+
+
 // WARNING: STATS_COUNTER_LIST_* is a very large macro that is causing MSVC
 // Intellisense to crash.  It was broken into two macros (each of length 40
 // lines) rather than one macro (of length about 80 lines) to work around
 // this problem.  Please avoid using recursive macros of this length when
 // possible.
 #define STATS_COUNTER_LIST_1(SC)                                      \
   /* Global Handle Count*/                                            \
   SC(global_handles, V8.GlobalHandles)                                \
   /* Mallocs from PCRE */                                             \
   SC(pcre_mallocs, V8.PcreMallocCount)                                \
@@ skipping 210 matching lines @@
 
 
 // This file contains all the v8 counters that are in use.
 class Counters {
  public:
 #define HT(name, caption) \
   HistogramTimer* name() { return &name##_; }
   HISTOGRAM_TIMER_LIST(HT)
 #undef HT
 
+#define HP(name, caption) \
+  Histogram* name() { return &name##_; }
+  HISTOGRAM_PERCENTAGE_LIST(HP)
+#undef HP
+
 #define SC(name, caption) \
   StatsCounter* name() { return &name##_; }
   STATS_COUNTER_LIST_1(SC)
   STATS_COUNTER_LIST_2(SC)
 #undef SC
 
   enum Id {
 #define RATE_ID(name, caption) k_##name,
     HISTOGRAM_TIMER_LIST(RATE_ID)
 #undef RATE_ID
+#define PERCENTAGE_ID(name, caption) k_##name,
+    HISTOGRAM_PERCENTAGE_LIST(PERCENTAGE_ID)
+#undef PERCENTAGE_ID
 #define COUNTER_ID(name, caption) k_##name,
     STATS_COUNTER_LIST_1(COUNTER_ID)
     STATS_COUNTER_LIST_2(COUNTER_ID)
 #undef COUNTER_ID
 #define COUNTER_ID(name) k_##name,
     STATE_TAG_LIST(COUNTER_ID)
 #undef COUNTER_ID
     stats_counter_count
   };
 
   StatsCounter* state_counters(StateTag state) {
     return &state_counters_[state];
   }
 
  private:
 #define HT(name, caption) \
   HistogramTimer name##_;
   HISTOGRAM_TIMER_LIST(HT)
 #undef HT
 
+#define HP(name, caption) \
+  Histogram name##_;
+  HISTOGRAM_PERCENTAGE_LIST(HP)
+#undef HP
+
 #define SC(name, caption) \
   StatsCounter name##_;
   STATS_COUNTER_LIST_1(SC)
   STATS_COUNTER_LIST_2(SC)
 #undef SC
 
   enum {
 #define COUNTER_ID(name) __##name,
     STATE_TAG_LIST(COUNTER_ID)
 #undef COUNTER_ID
     kSlidingStateWindowCounterCount
   };
 
   // Sliding state window counters.
   StatsCounter state_counters_[kSlidingStateWindowCounterCount];
   friend class Isolate;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(Counters);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8_COUNTERS_H_