src/hotspot/share/runtime/objectMonitor.cpp

*** 247,257 ****
  void ObjectMonitor::enter(TRAPS) {
    // The following code is ordered to check the most common cases first
    // and to reduce RTS->RTO cache line upgrades on SPARC and IA32 processors.
    Thread * const Self = THREAD;
  
!   void * cur = Atomic::cmpxchg((void*)Self, &_owner, (void*)NULL);
    if (cur == NULL) {
      // Either ASSERT _recursions == 0 or explicitly set _recursions = 0.
      assert(_recursions == 0, "invariant");
      assert(_owner == Self, "invariant");
      return;
--- 247,257 ----
  void ObjectMonitor::enter(TRAPS) {
    // The following code is ordered to check the most common cases first
    // and to reduce RTS->RTO cache line upgrades on SPARC and IA32 processors.
    Thread * const Self = THREAD;
  
!   void * cur = Atomic::cmpxchg(Self, &_owner, (void*)NULL);
    if (cur == NULL) {
      // Either ASSERT _recursions == 0 or explicitly set _recursions = 0.
      assert(_recursions == 0, "invariant");
      assert(_owner == Self, "invariant");
      return;
*** 404,414 ****
  // Callers must compensate as needed.
  
  int ObjectMonitor::TryLock(Thread * Self) {
    void * own = _owner;
    if (own != NULL) return 0;
!   if (Atomic::cmpxchg((void*)Self, &_owner, (void*)NULL) == NULL) {
      // Either guarantee _recursions == 0 or set _recursions = 0.
      assert(_recursions == 0, "invariant");
      assert(_owner == Self, "invariant");
      return 1;
    }
--- 404,414 ----
  // Callers must compensate as needed.
  
  int ObjectMonitor::TryLock(Thread * Self) {
    void * own = _owner;
    if (own != NULL) return 0;
!   if (Atomic::cmpxchg(Self, &_owner, (void*)NULL) == NULL) {
      // Either guarantee _recursions == 0 or set _recursions = 0.
      assert(_recursions == 0, "invariant");
      assert(_owner == Self, "invariant");
      return 1;
    }
*** 990,1000 ****
        // Only the current lock owner can manipulate the EntryList or
        // drain _cxq, so we need to reacquire the lock.  If we fail
        // to reacquire the lock the responsibility for ensuring succession
        // falls to the new owner.
        //
!       if (Atomic::cmpxchg((void*)THREAD, &_owner, (void*)NULL) != NULL) {
          return;
        }
        TEVENT(Exit - Reacquired);
      } else {
        if ((intptr_t(_EntryList)|intptr_t(_cxq)) == 0 || _succ != NULL) {
--- 990,1000 ----
        // Only the current lock owner can manipulate the EntryList or
        // drain _cxq, so we need to reacquire the lock.  If we fail
        // to reacquire the lock the responsibility for ensuring succession
        // falls to the new owner.
        //
!       if (Atomic::cmpxchg(THREAD, &_owner, (void*)NULL) != NULL) {
          return;
        }
        TEVENT(Exit - Reacquired);
      } else {
        if ((intptr_t(_EntryList)|intptr_t(_cxq)) == 0 || _succ != NULL) {
*** 1015,1025 ****
          //     we either restart/rerun the exit operation, or simply
          //     fall-through into the code below which wakes a successor.
          // B.  If the elements forming the EntryList|cxq are TSM
          //     we could simply unpark() the lead thread and return
          //     without having set _succ.
!         if (Atomic::cmpxchg((void*)THREAD, &_owner, (void*)NULL) != NULL) {
            TEVENT(Inflated exit - reacquired succeeded);
            return;
          }
          TEVENT(Inflated exit - reacquired failed);
        } else {
--- 1015,1025 ----
          //     we either restart/rerun the exit operation, or simply
          //     fall-through into the code below which wakes a successor.
          // B.  If the elements forming the EntryList|cxq are TSM
          //     we could simply unpark() the lead thread and return
          //     without having set _succ.
!         if (Atomic::cmpxchg(THREAD, &_owner, (void*)NULL) != NULL) {
            TEVENT(Inflated exit - reacquired succeeded);
            return;
          }
          TEVENT(Inflated exit - reacquired failed);
        } else {
*** 1978,1988 ****
      // the spin without prejudice or apply a "penalty" to the
      // spin count-down variable "ctr", reducing it by 100, say.
  
      Thread * ox = (Thread *) _owner;
      if (ox == NULL) {
!       ox = (Thread*)Atomic::cmpxchg((void*)Self, &_owner, (void*)NULL);
        if (ox == NULL) {
          // The CAS succeeded -- this thread acquired ownership
          // Take care of some bookkeeping to exit spin state.
          if (sss && _succ == Self) {
            _succ = NULL;
--- 1978,1988 ----
      // the spin without prejudice or apply a "penalty" to the
      // spin count-down variable "ctr", reducing it by 100, say.
  
      Thread * ox = (Thread *) _owner;
      if (ox == NULL) {
!       ox = (Thread*)Atomic::cmpxchg(Self, &_owner, (void*)NULL);
        if (ox == NULL) {
          // The CAS succeeded -- this thread acquired ownership
          // Take care of some bookkeeping to exit spin state.
          if (sss && _succ == Self) {
            _succ = NULL;