Make old-space heap stats safe for parallel marking.

runtime/vm/class_table.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_CLASS_TABLE_H_
 #define VM_CLASS_TABLE_H_
 
 #include "platform/assert.h"
 #include "vm/bitfield.h"
 #include "vm/globals.h"
@@ skipping 25 matching lines @@
   void AddNew(T size) {
     new_count++;
     new_size += size;
   }
 
   void ResetOld() {
     old_count = 0;
     old_size = 0;
   }
 
-  void AddOld(T size) {
-    old_count++;
+  void AddOld(T size, T count = 1) {
+    old_count += count;
     old_size += size;
   }
 
   void Reset() {
     new_count = 0;
     new_size = 0;
     old_count = 0;
     old_size = 0;
   }
 
@@ skipping 157 matching lines @@
   void AllocationProfilePrintJSON(JSONStream* stream);
   void ResetAllocationAccumulators();
 
   // Deallocates table copies. Do not call during concurrent access to table.
   void FreeOldTables();
 
   void SetTraceAllocationFor(intptr_t cid, bool trace);
   bool TraceAllocationFor(intptr_t cid);
 
  private:
-  friend class MarkingVisitor;
+  friend class GCMarker;
   friend class ScavengerVisitor;
   friend class ClassHeapStatsTestHelper;
   static const int initial_capacity_ = 512;
   static const int capacity_increment_ = 256;
 
   static bool ShouldUpdateSizeForClassId(intptr_t cid);
 
   intptr_t top_;
   intptr_t capacity_;
 
   // Copy-on-write is used for table_, with old copies stored in old_tables_.
   RawClass** table_;
   MallocGrowableArray<RawClass**>* old_tables_;
 
   ClassHeapStats* class_heap_stats_table_;
 
   ClassHeapStats* predefined_class_heap_stats_table_;
 
   // May not have updated size for variable size classes.
   ClassHeapStats* PreliminaryStatsAt(intptr_t cid);
-  void UpdateLiveOld(intptr_t cid, intptr_t size);
+  void UpdateLiveOld(intptr_t cid, intptr_t size, intptr_t count = 1);
   void UpdateLiveNew(intptr_t cid, intptr_t size);
 
   DISALLOW_COPY_AND_ASSIGN(ClassTable);
 };
 
 }  // namespace dart
 
 #endif  // VM_CLASS_TABLE_H_