- Revert r24564 and r24563 due to unexplained malloc corruption.

runtime/vm/gc_marker.cc

 // 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.
 
 #include "vm/gc_marker.h"
 
 #include <map>
 #include <utility>
 
 #include "vm/allocation.h"
@@ skipping 361 matching lines @@
       !raw_key->IsMarked()) {
     // Key is white.  Delay the weak property.
     visitor->DelayWeakProperty(raw_weak);
   } else {
     // Key is gray or black.  Make the weak property black.
     raw_weak->VisitPointers(visitor);
   }
 }
 
 
-void GCMarker::ProcessWeakTables(PageSpace* page_space) {
-  for (int sel = 0;
-       sel < Heap::kNumWeakSelectors;
-       sel++) {
-    WeakTable* table = heap_->GetWeakTable(
-        Heap::kOld, static_cast<Heap::WeakSelector>(sel));
-    intptr_t size = table->size();
-    for (intptr_t i = 0; i < size; i++) {
-      if (table->IsValidEntryAt(i)) {
-        RawObject* raw_obj = table->ObjectAt(i);
-        ASSERT(raw_obj->IsHeapObject());
-        if (!raw_obj->IsMarked()) {
-          table->InvalidateAt(i);
-        }
-      }
+void GCMarker::ProcessPeerReferents(PageSpace* page_space) {
+  PageSpace::PeerTable* peer_table = page_space->GetPeerTable();
+  PageSpace::PeerTable::iterator it = peer_table->begin();
+  while (it != peer_table->end()) {
+    RawObject* raw_obj = it->first;
+    ASSERT(raw_obj->IsHeapObject());
+    if (raw_obj->IsMarked()) {
+      // The object has survived.  Do nothing.
+      ++it;
+    } else {
+      // The object has become garbage.  Remove its record.
+      peer_table->erase(it++);
     }
   }
 }
 
 
 void GCMarker::MarkObjects(Isolate* isolate,
                            PageSpace* page_space,
                            bool invoke_api_callbacks) {
   MarkingStack marking_stack;
   Prologue(isolate, invoke_api_callbacks);
   MarkingVisitor mark(isolate, heap_, page_space, &marking_stack);
   IterateRoots(isolate, &mark, !invoke_api_callbacks);
   DrainMarkingStack(isolate, &mark);
   IterateWeakReferences(isolate, &mark);
   MarkingWeakVisitor mark_weak;
   IterateWeakRoots(isolate, &mark_weak, invoke_api_callbacks);
   mark.Finalize();
-  ProcessWeakTables(page_space);
+  ProcessPeerReferents(page_space);
   Epilogue(isolate, invoke_api_callbacks);
 }
 
 }  // namespace dart