diff -r a19c671188cb -r f1c12354c3f7 src/share/vm/opto/memnode.hpp
--- a/src/share/vm/opto/memnode.hpp	Mon Aug 08 13:19:46 2011 -0700
+++ b/src/share/vm/opto/memnode.hpp	Tue Aug 02 18:36:40 2011 +0200
@@ -879,7 +879,7 @@
 
 // "Acquire" - no following ref can move before (but earlier refs can
 // follow, like an early Load stalled in cache).  Requires multi-cpu
-// visibility.  Inserted after a volatile load or FastLock.
+// visibility.  Inserted after a volatile load.
 class MemBarAcquireNode: public MemBarNode {
 public:
   MemBarAcquireNode(Compile* C, int alias_idx, Node* precedent)
@@ -889,7 +889,7 @@
 
 // "Release" - no earlier ref can move after (but later refs can move
 // up, like a speculative pipelined cache-hitting Load).  Requires
-// multi-cpu visibility.  Inserted before a volatile store or FastUnLock.
+// multi-cpu visibility.  Inserted before a volatile store.
 class MemBarReleaseNode: public MemBarNode {
 public:
   MemBarReleaseNode(Compile* C, int alias_idx, Node* precedent)
@@ -897,6 +897,26 @@
   virtual int Opcode() const;
 };
 
+// "Acquire" - no following ref can move before (but earlier refs can
+// follow, like an early Load stalled in cache).  Requires multi-cpu
+// visibility.  Inserted after a FastLock.
+class MemBarAcquireLockNode: public MemBarNode {
+public:
+  MemBarAcquireLockNode(Compile* C, int alias_idx, Node* precedent)
+    : MemBarNode(C, alias_idx, precedent) {}
+  virtual int Opcode() const;
+};
+
+// "Release" - no earlier ref can move after (but later refs can move
+// up, like a speculative pipelined cache-hitting Load).  Requires
+// multi-cpu visibility.  Inserted before a FastUnLock.
+class MemBarReleaseLockNode: public MemBarNode {
+public:
+  MemBarReleaseLockNode(Compile* C, int alias_idx, Node* precedent)
+    : MemBarNode(C, alias_idx, precedent) {}
+  virtual int Opcode() const;
+};
+
 // Ordering between a volatile store and a following volatile load.
 // Requires multi-CPU visibility?
 class MemBarVolatileNode: public MemBarNode {