1996   // shake out uses of park() and unpark() without checking state conditions

  1996   // shake out uses of park() and unpark() without checking state conditions

  1997   // properly. This spurious return doesn't manifest itself in any user code

  1997   // properly. This spurious return doesn't manifest itself in any user code

  1998   // but only in the correctly written condition checking loops of ObjectMonitor,

  1998   // but only in the correctly written condition checking loops of ObjectMonitor,

  1999   // Mutex/Monitor, Thread::muxAcquire and JavaThread::sleep

  1999   // Mutex/Monitor, Thread::muxAcquire and JavaThread::sleep

  2000 

  2000 

  2002 

  2002 

  2003   int status = pthread_mutex_lock(_mutex);

  2003   int status = pthread_mutex_lock(_mutex);

  2004   assert_status(status == 0, status, "mutex_lock");

  2004   assert_status(status == 0, status, "mutex_lock");

  2005   int anyWaiters = _nParked;

  2005   int anyWaiters = _nParked;

  2006   assert(anyWaiters == 0 || anyWaiters == 1, "invariant");

  2006   assert(anyWaiters == 0 || anyWaiters == 1, "invariant");

  2044 

  2044 

  2045   // Optional fast-path check:

  2045   // Optional fast-path check:

  2046   // Return immediately if a permit is available.

  2046   // Return immediately if a permit is available.

  2047   // We depend on Atomic::xchg() having full barrier semantics

  2047   // We depend on Atomic::xchg() having full barrier semantics

  2048   // since we are doing a lock-free update to _counter.

  2048   // since we are doing a lock-free update to _counter.

  2050 

  2050 

  2051   Thread* thread = Thread::current();

  2051   Thread* thread = Thread::current();

  2052   assert(thread->is_Java_thread(), "Must be JavaThread");

  2052   assert(thread->is_Java_thread(), "Must be JavaThread");

  2053   JavaThread *jt = (JavaThread *)thread;

  2053   JavaThread *jt = (JavaThread *)thread;

  2054 

  2054