Lazy peer API.

runtime/vm/scavenger.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_SCAVENGER_H_
 #define VM_SCAVENGER_H_
 
+#include <map>
+
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/flags.h"
 #include "vm/globals.h"
 #include "vm/raw_object.h"
 #include "vm/virtual_memory.h"
 #include "vm/visitor.h"
 
 namespace dart {
 
@@ skipping 62 matching lines @@
     *end = to_->end();
   }
 
   // Returns true if the last scavenge had a promotion failure.
   bool HadPromotionFailure() {
     return had_promotion_failure_;
   }
 
   void WriteProtect(bool read_only);
 
+  void SetPeer(RawObject* raw_obj, void* peer);
+
+  void* GetPeer(RawObject* raw_obj);
+
+  int64_t PeerCount() const;
+
  private:
   uword FirstObjectStart() const { return to_->start() | object_alignment_; }
   void Prologue(Isolate* isolate, bool invoke_api_callbacks);
   void IterateStoreBuffers(Isolate* isolate, ScavengerVisitor* visitor);
   void IterateRoots(Isolate* isolate,
                     ScavengerVisitor* visitor,
                     bool visit_prologue_weak_persistent_handles);
   void IterateWeakProperties(Isolate* isolate, ScavengerVisitor* visitor);
   void IterateWeakReferences(Isolate* isolate, ScavengerVisitor* visitor);
   void IterateWeakRoots(Isolate* isolate,
@@ skipping 18 matching lines @@
   uword PopFromPromotedStack() {
     uword result = *reinterpret_cast<uword*>(end_);
     end_ += sizeof(result);
     ASSERT(end_ <= to_->end());
     return result;
   }
   bool PromotedStackHasMore() const {
     return end_ < to_->end();
   }
 
+  void ProcessPeerReferents();
+
   VirtualMemory* space_;
   MemoryRegion* to_;
   MemoryRegion* from_;
 
   Heap* heap_;
 
+  typedef std::map<RawObject*, void*> PeerTable;
+  PeerTable peer_table_;
+
   // Current allocation top and end. These values are being accessed directly
   // from generated code.
   uword top_;
   uword end_;
 
   // A pointer to the first unscanned object.  Scanning completes when
   // this value meets the allocation top.
   uword resolved_top_;
 
   // Objects below this address have survived a scavenge.
@@ skipping 11 matching lines @@
 
   friend class ScavengerVisitor;
   friend class ScavengerWeakVisitor;
 
   DISALLOW_COPY_AND_ASSIGN(Scavenger);
 };
 
 }  // namespace dart
 
 #endif  // VM_SCAVENGER_H_