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

src/heap.cc

 // 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 427 matching lines @@
 #endif
 
   isolate_->counters()->alive_after_last_gc()->Set(
       static_cast<int>(SizeOfObjects()));
 
   isolate_->counters()->symbol_table_capacity()->Set(
       symbol_table()->Capacity());
   isolate_->counters()->number_of_symbols()->Set(
       symbol_table()->NumberOfElements());
 
-  isolate_->counters()->new_space_bytes_available()->Set(
-      static_cast<int>(new_space()->Available()));
-  isolate_->counters()->new_space_bytes_committed()->Set(
-      static_cast<int>(new_space()->CommittedMemory()));
-  isolate_->counters()->new_space_bytes_used()->Set(
-      static_cast<int>(new_space()->SizeOfObjects()));
-
-  isolate_->counters()->old_pointer_space_bytes_available()->Set(
-      static_cast<int>(old_pointer_space()->Available()));
-  isolate_->counters()->old_pointer_space_bytes_committed()->Set(
-      static_cast<int>(old_pointer_space()->CommittedMemory()));
-  isolate_->counters()->old_pointer_space_bytes_used()->Set(
-      static_cast<int>(old_pointer_space()->SizeOfObjects()));
-
-  isolate_->counters()->old_data_space_bytes_available()->Set(
-      static_cast<int>(old_data_space()->Available()));
-  isolate_->counters()->old_data_space_bytes_committed()->Set(
-      static_cast<int>(old_data_space()->CommittedMemory()));
-  isolate_->counters()->old_data_space_bytes_used()->Set(
-      static_cast<int>(old_data_space()->SizeOfObjects()));
-
-  isolate_->counters()->code_space_bytes_available()->Set(
-      static_cast<int>(code_space()->Available()));
-  isolate_->counters()->code_space_bytes_committed()->Set(
-      static_cast<int>(code_space()->CommittedMemory()));
-  isolate_->counters()->code_space_bytes_used()->Set(
-      static_cast<int>(code_space()->SizeOfObjects()));
-
-  isolate_->counters()->map_space_bytes_available()->Set(
-      static_cast<int>(map_space()->Available()));
-  isolate_->counters()->map_space_bytes_committed()->Set(
-      static_cast<int>(map_space()->CommittedMemory()));
-  isolate_->counters()->map_space_bytes_used()->Set(
-      static_cast<int>(map_space()->SizeOfObjects()));
-
-  isolate_->counters()->cell_space_bytes_available()->Set(
-      static_cast<int>(cell_space()->Available()));
-  isolate_->counters()->cell_space_bytes_committed()->Set(
-      static_cast<int>(cell_space()->CommittedMemory()));
-  isolate_->counters()->cell_space_bytes_used()->Set(
-      static_cast<int>(cell_space()->SizeOfObjects()));
-
-  isolate_->counters()->lo_space_bytes_available()->Set(
-      static_cast<int>(lo_space()->Available()));
-  isolate_->counters()->lo_space_bytes_committed()->Set(
-      static_cast<int>(lo_space()->CommittedMemory()));
-  isolate_->counters()->lo_space_bytes_used()->Set(
-      static_cast<int>(lo_space()->SizeOfObjects()));
+#define UPDATE_COUNTERS_FOR_SPACE(space)                                     \
+  isolate_->counters()->space##_bytes_available()->Set(                      \
+      static_cast<int>(space()->Available()));                               \
+  isolate_->counters()->space##_bytes_committed()->Set(                      \
+      static_cast<int>(space()->CommittedMemory()));                         \
+  isolate_->counters()->space##_bytes_used()->Set(                           \
+      static_cast<int>(space()->SizeOfObjects()));                           \
+  if (space()->CommittedMemory() > 0) {                                      \
+    isolate_->counters()->external_fragmentation_##space()->AddSample(       \
+        static_cast<int>(                                                    \
+            (space()->SizeOfObjects() * 100) / space()->CommittedMemory())); \
+  }
+  UPDATE_COUNTERS_FOR_SPACE(new_space)
+  UPDATE_COUNTERS_FOR_SPACE(old_pointer_space)
+  UPDATE_COUNTERS_FOR_SPACE(old_data_space)
+  UPDATE_COUNTERS_FOR_SPACE(code_space)
+  UPDATE_COUNTERS_FOR_SPACE(map_space)
+  UPDATE_COUNTERS_FOR_SPACE(cell_space)
+  UPDATE_COUNTERS_FOR_SPACE(lo_space)
+#undef UPDATE_COUNTERS_FOR_SPACE
 
 #if defined(DEBUG)
   ReportStatisticsAfterGC();
 #endif  // DEBUG
 #ifdef ENABLE_DEBUGGER_SUPPORT
   isolate_->debug()->AfterGarbageCollection();
 #endif  // ENABLE_DEBUGGER_SUPPORT
 }
 
 
@@ skipping 6713 matching lines @@
   } else {
     p ^= 0x1d1ed & (Page::kPageSize - 1);  // I died.
   }
   remembered_unmapped_pages_[remembered_unmapped_pages_index_] =
       reinterpret_cast<Address>(p);
   remembered_unmapped_pages_index_++;
   remembered_unmapped_pages_index_ %= kRememberedUnmappedPages;
 }
 
 } }  // namespace v8::internal