src/hotspot/share/runtime/objectMonitor.hpp

rev 54612 : Checkpoint latest preliminary review patches for full OpenJDK review; merge with 8222295.patch.
rev 54613 : imported patch dcubed.monitor_deflate_conc.v2.01
rev 54615 : imported patch dcubed.monitor_deflate_conc.v2.03

*** 166,182 ****
    volatile int _Spinner;            // for exit->spinner handoff optimization
    volatile int _SpinDuration;
  
    volatile jint  _contentions;      // Number of active contentions in enter(). It is used by is_busy()
                                      // along with other fields to determine if an ObjectMonitor can be
!                                     // deflated. See ObjectSynchronizer::deflate_monitor().
   protected:
    ObjectWaiter * volatile _WaitSet; // LL of threads wait()ing on the monitor
    volatile jint  _waiters;          // number of waiting threads
   private:
    volatile int _WaitSetLock;        // protects Wait Queue - simple spinlock
!   volatile jint _ref_count;         // ref count for ObjectMonitor*
    typedef enum {
      Free = 0,  // Free must be 0 for monitor to be free after memset(..,0,..).
      New,
      Old
    } AllocationState;
--- 166,184 ----
    volatile int _Spinner;            // for exit->spinner handoff optimization
    volatile int _SpinDuration;
  
    volatile jint  _contentions;      // Number of active contentions in enter(). It is used by is_busy()
                                      // along with other fields to determine if an ObjectMonitor can be
!                                     // deflated. See ObjectSynchronizer::deflate_monitor() and
!                                     // ObjectSynchronizer::deflate_monitor_using_JT().
   protected:
    ObjectWaiter * volatile _WaitSet; // LL of threads wait()ing on the monitor
    volatile jint  _waiters;          // number of waiting threads
   private:
    volatile int _WaitSetLock;        // protects Wait Queue - simple spinlock
!   volatile jint _ref_count;         // ref count for ObjectMonitor* and used by the async deflation
!                                     // protocol. See ObjectSynchronizer::deflate_monitor_using_JT().
    typedef enum {
      Free = 0,  // Free must be 0 for monitor to be free after memset(..,0,..).
      New,
      Old
    } AllocationState;
*** 247,266 ****
      // use which is orthogonal to whether the ObjectMonitor itself
      // is in use for a locking operation.
      return _contentions|_waiters|intptr_t(_owner)|intptr_t(_cxq)|intptr_t(_EntryList);
    }
  
!   // Version of is_busy() that accounts for special values in
!   // _contentions and _owner when AsyncDeflateIdleMonitors is enabled.
    intptr_t is_busy_async() const {
!     intptr_t ret_code = _waiters | intptr_t(_cxq) | intptr_t(_EntryList);
      if (!AsyncDeflateIdleMonitors) {
!       ret_code |= _contentions | intptr_t(_owner);
      } else {
-       if (_contentions > 0) {
-         ret_code |= _contentions;
-       }
        if (_owner != DEFLATER_MARKER) {
          ret_code |= intptr_t(_owner);
        }
      }
      return ret_code;
--- 249,265 ----
      // use which is orthogonal to whether the ObjectMonitor itself
      // is in use for a locking operation.
      return _contentions|_waiters|intptr_t(_owner)|intptr_t(_cxq)|intptr_t(_EntryList);
    }
  
!   // Version of is_busy() that accounts for the special value in
!   // _owner when AsyncDeflateIdleMonitors is enabled.
    intptr_t is_busy_async() const {
!     intptr_t ret_code = _contentions | _waiters | intptr_t(_cxq) | intptr_t(_EntryList);
      if (!AsyncDeflateIdleMonitors) {
!       ret_code |= intptr_t(_owner);
      } else {
        if (_owner != DEFLATER_MARKER) {
          ret_code |= intptr_t(_owner);
        }
      }
      return ret_code;
*** 324,342 ****
    bool      check(TRAPS);       // true if the thread owns the monitor.
    void      check_slow(TRAPS);
    void      clear();
    void      clear_using_JT();
  
!   bool      enter(TRAPS);  // Returns false if monitor is being async deflated and caller should retry locking the object.
    void      exit(bool not_suspended, TRAPS);
    void      wait(jlong millis, bool interruptable, TRAPS);
    void      notify(TRAPS);
    void      notifyAll(TRAPS);
  
  // Use the following at your own risk
    intptr_t  complete_exit(TRAPS);
!   bool      reenter(intptr_t recursions, TRAPS);  // Returns false if monitor is being async deflated and caller should retry locking the object.
  
   private:
    void      AddWaiter(ObjectWaiter * waiter);
    void      INotify(Thread * Self);
    ObjectWaiter * DequeueWaiter();
--- 323,341 ----
    bool      check(TRAPS);       // true if the thread owns the monitor.
    void      check_slow(TRAPS);
    void      clear();
    void      clear_using_JT();
  
!   void      enter(TRAPS);
    void      exit(bool not_suspended, TRAPS);
    void      wait(jlong millis, bool interruptable, TRAPS);
    void      notify(TRAPS);
    void      notifyAll(TRAPS);
  
  // Use the following at your own risk
    intptr_t  complete_exit(TRAPS);
!   void      reenter(intptr_t recursions, TRAPS);
  
   private:
    void      AddWaiter(ObjectWaiter * waiter);
    void      INotify(Thread * Self);
    ObjectWaiter * DequeueWaiter();