src/hotspot/share/runtime/objectMonitor.inline.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 54614 : imported patch dcubed.monitor_deflate_conc.v2.02
rev 54615 : imported patch dcubed.monitor_deflate_conc.v2.03

*** 47,69 ****
  
  inline jint ObjectMonitor::waiters() const {
    return _waiters;
  }
  
  inline void* ObjectMonitor::owner() const {
!   return _owner;
  }
  
  inline void ObjectMonitor::clear() {
    assert(_header != NULL, "must be non-NULL");
    assert(_contentions == 0, "must be 0: contentions=%d", _contentions);
    assert(_waiters == 0, "must be 0: waiters=%d", _waiters);
    assert(_recursions == 0, "must be 0: recursions=" INTPTR_FORMAT, _recursions);
    assert(_object != NULL, "must be non-NULL");
-   assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
  
!   _header = NULL;
    _object = NULL;
  }
  
  inline void* ObjectMonitor::object() const {
    return _object;
--- 47,96 ----
  
  inline jint ObjectMonitor::waiters() const {
    return _waiters;
  }
  
+ // Returns NULL if DEFLATER_MARKER is observed.
  inline void* ObjectMonitor::owner() const {
!   void* owner = _owner;
!   return owner != DEFLATER_MARKER ? owner : NULL;
  }
  
  inline void ObjectMonitor::clear() {
    assert(_header != NULL, "must be non-NULL");
+   assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
+   assert(_ref_count == 0, "must be 0: ref_count=%d", _ref_count);
+ 
+   _header = NULL;
+ 
+   clear_using_JT();
+ }
+ 
+ inline void ObjectMonitor::clear_using_JT() {
+   // Unlike other *_using_JT() functions, we cannot assert
+   // AsyncDeflateIdleMonitors or Thread::current()->is_Java_thread()
+   // because clear() calls this function for the rest of its checks.
+ 
+   if (AsyncDeflateIdleMonitors) {
+     // Async deflation protocol uses the header, owner and ref_count
+     // fields. While the ObjectMonitor being deflated is on the global free
+     // list, we leave those three fields alone; owner == DEFLATER_MARKER
+     // and ref_count < 0 will force any racing threads to retry. The
+     // header field is used by install_displaced_markword_in_object()
+     // in the last part of the deflation protocol so we cannot check
+     // its value here.
+     guarantee(_owner == NULL || _owner == DEFLATER_MARKER,
+               "must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT,
+               p2i(_owner));
+     guarantee(_ref_count <= 0, "must be <= 0: ref_count=%d", _ref_count);
+   }
    assert(_contentions == 0, "must be 0: contentions=%d", _contentions);
    assert(_waiters == 0, "must be 0: waiters=%d", _waiters);
    assert(_recursions == 0, "must be 0: recursions=" INTPTR_FORMAT, _recursions);
    assert(_object != NULL, "must be non-NULL");
  
!   set_allocation_state(Free);
    _object = NULL;
  }
  
  inline void* ObjectMonitor::object() const {
    return _object;
*** 101,106 ****
--- 128,180 ----
  inline void ObjectMonitor::set_owner(void* owner) {
    _owner = owner;
    _recursions = 0;
  }
  
+ inline void ObjectMonitor::set_allocation_state(ObjectMonitor::AllocationState s) {
+   _allocation_state = s;
+ }
+ 
+ inline ObjectMonitor::AllocationState ObjectMonitor::allocation_state() const {
+   return _allocation_state;
+ }
+ 
+ inline bool ObjectMonitor::is_free() const {
+   return _allocation_state == Free;
+ }
+ 
+ inline bool ObjectMonitor::is_active() const {
+   return !is_free();
+ }
+ 
+ inline bool ObjectMonitor::is_old() const {
+   return _allocation_state == Old;
+ }
+ 
+ inline bool ObjectMonitor::is_new() const {
+   return _allocation_state == New;
+ }
+ 
+ inline void ObjectMonitor::dec_ref_count() {
+   // The decrement only needs to be MO_ACQ_REL since the reference
+   // counter is volatile.
+   Atomic::dec(&_ref_count);
+   // Can be negative as part of async deflation protocol.
+   guarantee(AsyncDeflateIdleMonitors || _ref_count >= 0,
+             "sanity check: ref_count=%d", _ref_count);
+ }
+ 
+ inline void ObjectMonitor::inc_ref_count() {
+   // The increment needs to be MO_SEQ_CST so that the reference
+   // counter update is seen as soon as possible in a race with the
+   // async deflation protocol.
+   Atomic::inc(&_ref_count);
+   // Can be negative as part of async deflation protocol.
+   guarantee(AsyncDeflateIdleMonitors || _ref_count > 0,
+             "sanity check: ref_count=%d", _ref_count);
+ }
+ 
+ inline jint ObjectMonitor::ref_count() const {
+   return OrderAccess::load_acquire(&_ref_count);
+ }
+ 
  #endif // SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP