- WeakProperty keys in other generations are black. Avoid trying to

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 350 matching lines @@
     }
   }
   visitor->set_update_store_buffers(false);
 }
 
 
 void GCMarker::ProcessWeakProperty(RawWeakProperty* raw_weak,
                                    MarkingVisitor* visitor) {
   // The fate of the weak property is determined by its key.
   RawObject* raw_key = raw_weak->ptr()->key_;
-  if (!raw_key->IsMarked()) {
+  if (raw_key->IsHeapObject() &&

[cshapiro, 2012/10/01 22:22:14]

Can we use IsUnreachable instead of the explicit conjunction?  The null check
inside IsUnreachable should be unnecessary now that the null object is
pre-marked.

[Ivan Posva, 2012/10/01 22:27:39]

Different CL.

+      raw_key->IsOldObject() &&
+      !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::ProcessPeerReferents(PageSpace* page_space) {
@@ skipping 23 matching lines @@
   DrainMarkingStack(isolate, &mark);
   IterateWeakReferences(isolate, &mark);
   MarkingWeakVisitor mark_weak;
   IterateWeakRoots(isolate, &mark_weak, invoke_api_callbacks);
   mark.Finalize();
   ProcessPeerReferents(page_space);
   Epilogue(isolate, invoke_api_callbacks);
 }
 
 }  // namespace dart