--- old/src/share/vm/memory/allocation.hpp	Mon Aug  2 14:26:19 2010
+++ new/src/share/vm/memory/allocation.hpp	Mon Aug  2 14:26:19 2010
@@ -316,12 +316,34 @@
 // use delete to deallocate.
 class ResourceObj ALLOCATION_SUPER_CLASS_SPEC {
  public:
-  enum allocation_type { UNKNOWN = 0, C_HEAP, RESOURCE_AREA, ARENA };
+  enum allocation_type { RESOURCE_AREA = 0, C_HEAP, ARENA, allocation_mask = 0x3 };
 #ifdef ASSERT
  private:
-  allocation_type _allocation;
+  // When this object is allocated on stack the new() operator is not
+  // called but garbage on stack may look like a valid allocation_type.
+  // Store negated 'this' pointer when new() is called to distinguish cases.
+  uintptr_t _allocation;
+  static void set_allocation_type(address res, allocation_type type) {
+      // Set allocation type in the resource object
+      uintptr_t allocation = (uintptr_t)res;
+      assert((allocation & allocation_mask) == 0, "");
+      assert(type < allocation_mask, "");
+      ((ResourceObj *)res)->_allocation = ~(allocation + type);
+  }
+  allocation_type get_allocation_type() {
+      return (allocation_type)((~_allocation) & allocation_mask);
+  }
  public:
-  bool allocated_on_C_heap()    { return _allocation == C_HEAP; }
+  bool allocated_on_stack()     { return get_allocation_type() == RESOURCE_AREA; }
+  bool allocated_on_C_heap()    { return get_allocation_type() == C_HEAP; }
+  bool allocated_on_arena()     { return get_allocation_type() == ARENA; }
+  ResourceObj() {
+    if (~(_allocation | allocation_mask) != (uintptr_t)this) {
+      set_allocation_type((address)this, RESOURCE_AREA);
+    } else {
+      assert(allocated_on_stack() || allocated_on_C_heap() || allocated_on_arena(), "");
+    }
+  }
 #endif // ASSERT
 
  public:
@@ -328,20 +350,17 @@
   void* operator new(size_t size, allocation_type type);
   void* operator new(size_t size, Arena *arena) {
       address res = (address)arena->Amalloc(size);
-      // Set allocation type in the resource object
-      DEBUG_ONLY(((ResourceObj *)res)->_allocation = ARENA;)
+      DEBUG_ONLY(set_allocation_type(res, ARENA);)
       return res;
   }
   void* operator new(size_t size) {
       address res = (address)resource_allocate_bytes(size);
-      // Set allocation type in the resource object
-      DEBUG_ONLY(((ResourceObj *)res)->_allocation = RESOURCE_AREA;)
+      DEBUG_ONLY(set_allocation_type(res, RESOURCE_AREA);)
       return res;
   }
   void* operator new(size_t size, void* where, allocation_type type) {
-      void* res = where;
-      // Set allocation type in the resource object
-      DEBUG_ONLY(((ResourceObj *)res)->_allocation = type;)
+      address res = (address)where;
+      DEBUG_ONLY(set_allocation_type(res, C_HEAP);)
       return res;
   }
   void  operator delete(void* p);