Ensure strings are never externalized as a side-effect of doing a GC.

src/heap.h

 // Copyright 2011 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 1035 matching lines @@
   inline void RecordWrites(Address address, int start, int len);
 
   // Given an address occupied by a live code object, return that object.
   Object* FindCodeObject(Address a);
 
   // Invoke Shrink on shrinkable spaces.
   void Shrink();
 
   enum HeapState { NOT_IN_GC, SCAVENGE, MARK_COMPACT };
   inline HeapState gc_state() { return gc_state_; }
+  
+  inline int gc_post_process_count() { return gc_post_process_count_; }

[Vyacheslav Egorov (Chromium), 2011/06/01 11:12:35]

Better make it a:

bool IsInGCPostProcessing() { return gc_post_process_count_ > 0; }

[sandholm, 2011/06/01 11:39:34]

Done.

+
 
 #ifdef DEBUG
   bool IsAllocationAllowed() { return allocation_allowed_; }
   inline bool allow_allocation(bool enable);
 
   bool disallow_allocation_failure() {
     return disallow_allocation_failure_;
   }
 
   void TracePathToObject(Object* target);
@@ skipping 204 matching lines @@
 #endif
 
   NewSpace new_space_;
   OldSpace* old_pointer_space_;
   OldSpace* old_data_space_;
   OldSpace* code_space_;
   MapSpace* map_space_;
   CellSpace* cell_space_;
   LargeObjectSpace* lo_space_;
   HeapState gc_state_;
+  int gc_post_process_count_;

[Vyacheslav Egorov (Chromium), 2011/06/01 11:12:35]

Name is a bit confusing. Consider naming it:

gc_post_processing_depth_

[sandholm, 2011/06/01 11:39:34]

Done.

 
   // Returns the size of object residing in non new spaces.
   intptr_t PromotedSpaceSize();
 
   // Returns the amount of external memory registered since last global gc.
   int PromotedExternalMemorySize();
 
   int mc_count_;  // how many mark-compact collections happened
   int ms_count_;  // how many mark-sweep collections happened
   unsigned int gc_count_;  // how many gc happened
@@ skipping 969 matching lines @@
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG || LIVE_OBJECT_LIST
 
 
 } }  // namespace v8::internal
 
 #undef HEAP
 
 #endif  // V8_HEAP_H_