Implement prologue weak persistent handles.

runtime/vm/heap.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_HEAP_H_
 #define VM_HEAP_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/flags.h"
@@ skipping 14 matching lines @@
 DECLARE_FLAG(bool, gc_at_alloc);
 
 class Heap {
  public:
   enum Space {
     kNew,
     kOld,
     kExecutable
   };
 
+  enum ApiCallbacks {
+    kIgnoreApiCallbacks,
+    kInvokeApiCallbacks
+  };
+
   // Default allocation sizes in MB for the old gen and code heaps.
   static const intptr_t kHeapSizeInMB = 512;
   static const intptr_t kCodeHeapSizeInMB = 8;
 
   ~Heap();
 
   uword Allocate(intptr_t size, Space space) {
     switch (space) {
       case kNew:
         // Do not attempt to allocate very large objects in new space.
@@ skipping 28 matching lines @@
   // Heap contains the specified address.
   bool Contains(uword addr) const;
   bool CodeContains(uword addr) const;
 
   // Visit all pointers in the space.
   void IterateNewPointers(ObjectPointerVisitor* visitor);
   void IterateOldPointers(ObjectPointerVisitor* visitor);
   void IterateCodePointers(ObjectPointerVisitor* visitor);
 
   void CollectGarbage(Space space);
+  void CollectGarbage(Space space, ApiCallbacks api_callbacks);
   void CollectAllGarbage();
 
   // Accessors for inlined allocation in generated code.
   uword TopAddress();
   uword EndAddress();
   static intptr_t new_space_offset() { return OFFSET_OF(Heap, new_space_); }
 
   // Initialize the heap and register it with the isolate.
   static void Init(Isolate* isolate);
 
@@ skipping 29 matching lines @@
  public:
   NoGCScope() {}
  private:
   DISALLOW_COPY_AND_ASSIGN(NoGCScope);
 };
 #endif  // defined(DEBUG)
 
 }  // namespace dart
 
 #endif  // VM_HEAP_H_