--- a/src/share/vm/oops/oop.inline.hpp	Tue Mar 11 15:34:06 2014 +0100
+++ b/src/share/vm/oops/oop.inline.hpp	Wed Mar 12 13:30:08 2014 +0100
@@ -147,12 +147,13 @@
 
 inline bool oopDesc::is_a(Klass* k)        const { return klass()->is_subtype_of(k); }
 
-inline bool oopDesc::is_instance()           const { return klass()->oop_is_instance(); }
-inline bool oopDesc::is_instanceMirror()     const { return klass()->oop_is_instanceMirror(); }
-inline bool oopDesc::is_instanceRef()        const { return klass()->oop_is_instanceRef(); }
-inline bool oopDesc::is_array()              const { return klass()->oop_is_array(); }
-inline bool oopDesc::is_objArray()           const { return klass()->oop_is_objArray(); }
-inline bool oopDesc::is_typeArray()          const { return klass()->oop_is_typeArray(); }
+inline bool oopDesc::is_instance()            const { return klass()->oop_is_instance(); }
+inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); }
+inline bool oopDesc::is_instanceMirror()      const { return klass()->oop_is_instanceMirror(); }
+inline bool oopDesc::is_instanceRef()         const { return klass()->oop_is_instanceRef(); }
+inline bool oopDesc::is_array()               const { return klass()->oop_is_array(); }
+inline bool oopDesc::is_objArray()            const { return klass()->oop_is_objArray(); }
+inline bool oopDesc::is_typeArray()           const { return klass()->oop_is_typeArray(); }
 
 inline void*     oopDesc::field_base(int offset)        const { return (void*)&((char*)this)[offset]; }
 
@@ -490,9 +491,9 @@
   return size_given_klass(klass());
 }
 
-inline void update_barrier_set(void* p, oop v) {
+inline void update_barrier_set(void* p, oop v, bool release = false) {
   assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
-  oopDesc::bs()->write_ref_field(p, v);
+  oopDesc::bs()->write_ref_field(p, v, release);
 }
 
 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
@@ -505,7 +506,10 @@
   } else {
     update_barrier_set_pre(p, v);
     oopDesc::encode_store_heap_oop(p, v);
-    update_barrier_set((void*)p, v);  // cast away type
+    // always_do_update_barrier == false =>
+    // Either we are at a safepoint (in GC) or CMS is not used. In both
+    // cases it's unnecessary to mark the card as dirty with release sematics.
+    update_barrier_set((void*)p, v, false /* release */);  // cast away type
   }
 }
 
@@ -513,7 +517,12 @@
   update_barrier_set_pre((T*)p, v);   // cast away volatile
   // Used by release_obj_field_put, so use release_store_ptr.
   oopDesc::release_encode_store_heap_oop(p, v);
-  update_barrier_set((void*)p, v);    // cast away type
+  // When using CMS we must mark the card corresponding to p as dirty
+  // with release sematics to prevent that CMS sees the dirty card but
+  // not the new value v at p due to reordering of the two
+  // stores. Note that CMS has a concurrent precleaning phase, where
+  // it reads the card table while the Java threads are running.
+  update_barrier_set((void*)p, v, true /* release */);    // cast away type
 }
 
 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops