Get rid of distinction between below- and above-watermark in page allocation....

src/heap.h

-// Copyright 2010 the V8 project authors. All rights reserved.
+// 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
 //       with the distribution.
@@ skipping 744 matching lines @@
   // Performs garbage collection operation.
   // Returns whether there is a chance that another major GC could
   // collect more garbage.
   static bool CollectGarbage(AllocationSpace space, GarbageCollector collector);
 
   // Performs garbage collection operation.
   // Returns whether there is a chance that another major GC could
   // collect more garbage.
   inline static bool CollectGarbage(AllocationSpace space);
 
+  static const int kNoGCFlags = 0;
+  static const int kForceCompactionMask = 1;
+  static const int kSweepPreciselyMask = 2;

[Vyacheslav Egorov (Chromium), 2011/03/15 09:20:09]

maybe better hide the concept of conservative and precise sweep and just call it
kEnsureIterableMask or something like that?

[Erik Corry, 2011/03/17 13:39:17]

Done.

+
   // Performs a full garbage collection. Force compaction if the
   // parameter is true.
-  static void CollectAllGarbage(bool force_compaction);
+  static void CollectAllGarbage(int flags);
+
+
+  // Ensure that we have swept all spaces in such a way that we can iterate
+  // over live objects.  May cause a GC.
+  static void EnsureHeapIsIterable();
 
   // Last hope GC, should try to squeeze as much as possible.
   static void CollectAllAvailableGarbage();
 
   // Notify the heap that a context has been disposed.
   static int NotifyContextDisposed() { return ++contexts_disposed_; }
 
   // Utility to invoke the scavenger. This is needed in test code to
   // ensure correct callback for weak global handles.
   static void PerformScavenge();
@@ skipping 824 matching lines @@
   ObjectIterator* CreateIterator();
 
   int current_space_;  // from enum AllocationSpace.
   ObjectIterator* iterator_;  // object iterator for the current space.
   HeapObjectCallback size_func_;
 };
 
 
 // A HeapIterator provides iteration over the whole heap. It
 // aggregates the specific iterators for the different spaces as
-// these can only iterate over one space only.
+// these can only iterate over one space only.  It can only be guaranteed
+// to iterate over live objects.
 //
 // HeapIterator can skip free list nodes (that is, de-allocated heap
 // objects that still remain in the heap). As implementation of free
 // nodes filtering uses GC marks, it can't be used during MS/MC GC
 // phases. Also, it is forbidden to interrupt iteration in this mode,
 // as this will leave heap objects marked (and thus, unusable).
 class HeapObjectsFilter;
 
 class HeapIterator BASE_EMBEDDED {
  public:
-  enum HeapObjectsFiltering {
-    kNoFiltering,
-    kFilterFreeListNodes,
-    kFilterUnreachable
-  };
-
   HeapIterator();
-  explicit HeapIterator(HeapObjectsFiltering filtering);
   ~HeapIterator();
 
-  HeapObject* next();
-  void reset();
+  HeapObject* Next();
+  void Reset();
 
  private:
   // Perform the initialization.
   void Init();
   // Perform all necessary shutdown (destruction) work.
   void Shutdown();
-  HeapObject* NextObject();
 
-  HeapObjectsFiltering filtering_;
-  HeapObjectsFilter* filter_;
   // Space iterator for iterating all the spaces.
   SpaceIterator* space_iterator_;
   // Object iterator for the space currently being iterated.
   ObjectIterator* object_iterator_;
 };
 
 
 // Cache for mapping (map, property name) into field offset.
 // Cleared at startup and prior to mark sweep collection.
 class KeyedLookupCache {
@@ skipping 517 matching lines @@
 
  private:
   static const uintptr_t kNotMarkedBit = 0x1;
   STATIC_ASSERT((kHeapObjectTag & kNotMarkedBit) != 0);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_