Deletion barrier preparation: validate overwritten references.

runtime/vm/pages.h

 // Copyright (c) 2011, 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_PAGES_H_
 #define VM_PAGES_H_
 
 #include "vm/freelist.h"
 #include "vm/globals.h"
 #include "vm/lockers.h"
@@ skipping 305 matching lines @@
   void set_tasks(intptr_t val) {
     ASSERT(val >= 0);
     tasks_ = val;
   }
 
   // Attempt to allocate from bump block rather than normal freelist.
   uword TryAllocateDataBump(intptr_t size, GrowthPolicy growth_policy);
   uword TryAllocateDataBumpLocked(intptr_t size, GrowthPolicy growth_policy);
   // Prefer small freelist blocks, then chip away at the bump block.
   uword TryAllocatePromoLocked(intptr_t size, GrowthPolicy growth_policy);
+  // Allocates memory where every word is guaranteed to be a Smi. Calling this
+  // method after the first garbage collection is inefficient in release mode
+  // and illegal in debug mode.
+  uword TryAllocateSmiInitializedLocked(intptr_t size,
+                                        GrowthPolicy growth_policy);
 
   // Bump block allocation from generated code.
   uword* TopAddress() { return &bump_top_; }
   uword* EndAddress() { return &bump_end_; }
 
  private:
   // Ids for time and data records in Heap::GCStats.
   enum {
     // Time
     kMarkObjects = 0,
@@ skipping 80 matching lines @@
   friend class ExclusivePageIterator;
   friend class PageSpaceController;
   friend class SweeperTask;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PageSpace);
 };
 
 }  // namespace dart
 
 #endif  // VM_PAGES_H_