src/hotspot/os/posix/os_posix.cpp

*** 1996,2006 ****
    // shake out uses of park() and unpark() without checking state conditions
    // properly. This spurious return doesn't manifest itself in any user code
    // but only in the correctly written condition checking loops of ObjectMonitor,
    // Mutex/Monitor, Thread::muxAcquire and JavaThread::sleep
  
!   if (Atomic::xchg(1, &_event) >= 0) return;
  
    int status = pthread_mutex_lock(_mutex);
    assert_status(status == 0, status, "mutex_lock");
    int anyWaiters = _nParked;
    assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
--- 1996,2006 ----
    // shake out uses of park() and unpark() without checking state conditions
    // properly. This spurious return doesn't manifest itself in any user code
    // but only in the correctly written condition checking loops of ObjectMonitor,
    // Mutex/Monitor, Thread::muxAcquire and JavaThread::sleep
  
!   if (Atomic::xchg(&_event, 1) >= 0) return;
  
    int status = pthread_mutex_lock(_mutex);
    assert_status(status == 0, status, "mutex_lock");
    int anyWaiters = _nParked;
    assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
*** 2044,2054 ****
  
    // Optional fast-path check:
    // Return immediately if a permit is available.
    // We depend on Atomic::xchg() having full barrier semantics
    // since we are doing a lock-free update to _counter.
!   if (Atomic::xchg(0, &_counter) > 0) return;
  
    Thread* thread = Thread::current();
    assert(thread->is_Java_thread(), "Must be JavaThread");
    JavaThread *jt = (JavaThread *)thread;
  
--- 2044,2054 ----
  
    // Optional fast-path check:
    // Return immediately if a permit is available.
    // We depend on Atomic::xchg() having full barrier semantics
    // since we are doing a lock-free update to _counter.
!   if (Atomic::xchg(&_counter, 0) > 0) return;
  
    Thread* thread = Thread::current();
    assert(thread->is_Java_thread(), "Must be JavaThread");
    JavaThread *jt = (JavaThread *)thread;