diff -r 3ab9867d7786 -r 381638db28e6 hotspot/src/os/linux/vm/os_linux.cpp
--- a/hotspot/src/os/linux/vm/os_linux.cpp	Thu Jul 03 09:16:56 2014 -0700
+++ b/hotspot/src/os/linux/vm/os_linux.cpp	Thu Jul 03 11:07:51 2014 -0700
@@ -5457,22 +5457,12 @@
   return abstime;
 }
 
-
-// Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
-// Conceptually TryPark() should be equivalent to park(0).
-
-int os::PlatformEvent::TryPark() {
-  for (;;) {
-    const int v = _Event;
-    guarantee((v == 0) || (v == 1), "invariant");
-    if (Atomic::cmpxchg(0, &_Event, v) == v) return v;
-  }
-}
-
 void os::PlatformEvent::park() {       // AKA "down()"
   // Invariant: Only the thread associated with the Event/PlatformEvent
   // may call park().
   // TODO: assert that _Assoc != NULL or _Assoc == Self
+  assert(_nParked == 0, "invariant");
+
   int v;
   for (;;) {
       v = _Event;
@@ -5572,8 +5562,7 @@
   //    1 :=> 1
   //   -1 :=> either 0 or 1; must signal target thread
   //          That is, we can safely transition _Event from -1 to either
-  //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
-  //          unpark() calls.
+  //          0 or 1.
   // See also: "Semaphores in Plan 9" by Mullender & Cox
   //
   // Note: Forcing a transition from "-1" to "1" on an unpark() means
@@ -5801,10 +5790,9 @@
 }
 
 void Parker::unpark() {
-  int s, status;
-  status = pthread_mutex_lock(_mutex);
+  int status = pthread_mutex_lock(_mutex);
   assert(status == 0, "invariant");
-  s = _counter;
+  const int s = _counter;
   _counter = 1;
   if (s < 1) {
     // thread might be parked