two pass phantom collection

include/v8-util.h

Index: include/v8-util.h
diff --git a/include/v8-util.h b/include/v8-util.h
index 21990a8fd9c681c91c2599ab40434520a22b3a78..b01d527754b5ce758d641fadfabc0b7133d92c5f 100644
--- a/include/v8-util.h
+++ b/include/v8-util.h
@@ -322,7 +322,11 @@ class PersistentValueMapBase {
     return p.Pass();
   }
 
-  void RemoveWeak(const K& key) { Traits::Remove(&impl_, key); }
+  void RemoveWeak(const K& key) {
+    Global<V> p;
+    p.val_ = FromVal(Traits::Remove(&impl_, key));
+    p.Reset();

[Erik Corry, 2015/03/26 10:07:10]

Why do we have to create a Global, then immediately reset it?

[dcarney, 2015/03/26 10:26:56]

here nothing is being created.  we're just releasing the cell

+  }
 
  private:
   PersistentValueMapBase(PersistentValueMapBase&);
@@ -476,7 +480,6 @@ class GlobalValueMap : public PersistentValueMapBase<K, V, Traits> {
       K key = Traits::KeyFromWeakCallbackInfo(data);
       persistentValueMap->RemoveWeak(key);
       Traits::DisposeWeak(data.GetIsolate(), data, key);
-      Traits::DisposeCallbackData(data.GetParameter());
     }
   }
 };