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src/hotspot/share/runtime/objectMonitor.inline.hpp

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rev 56775 : imported patch 8230876.patch
rev 56776 : v2.00 -> v2.07 (CR7/v2.07/10-for-jdk14) patches combined into one; merge with 8230876.patch (2019.10.17) and jdk-14+21.
rev 56777 : See CR7-to-CR8-changes.

@@ -60,17 +60,18 @@
 
 // Returns true if owner field == DEFLATER_MARKER and false otherwise.
 // This accessor is called when we really need to know if the owner
 // field == DEFLATER_MARKER and any non-NULL value won't do the trick.
 inline bool ObjectMonitor::owner_is_DEFLATER_MARKER() {
-  return OrderAccess::load_acquire(&_owner) == DEFLATER_MARKER;
+  return _owner == DEFLATER_MARKER;
 }
 
 inline void ObjectMonitor::clear() {
   assert(Atomic::load(&_header).value() != 0, "must be non-zero");
   assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
-  assert(ref_count() == 0, "must be 0: ref_count=%d", ref_count());
+  DEBUG_ONLY(jint l_ref_count = ref_count();)
+  assert(l_ref_count == 0, "must be 0: l_ref_count=%d, ref_count=%d", l_ref_count, ref_count());
 
   Atomic::store(markWord::zero(), &_header);
 
   clear_using_JT();
 }

@@ -89,11 +90,12 @@
     // 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());
+    jint l_ref_count = ref_count();
+    guarantee(l_ref_count <= 0, "must be <= 0: l_ref_count=%d, ref_count=%d", l_ref_count, 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=" INTX_FORMAT, _recursions);
   assert(_object != NULL, "must be non-NULL");

@@ -122,53 +124,70 @@
 // Set _owner field to new_value; current value must match old_value.
 inline void ObjectMonitor::set_owner_from(void* new_value, void* old_value) {
   void* prev = Atomic::cmpxchg(new_value, &_owner, old_value);
   ADIM_guarantee(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
                  ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
-  log_trace(monitorinflation, owner)("mid=" INTPTR_FORMAT ", prev="
-                                     INTPTR_FORMAT ", new=" INTPTR_FORMAT,
-                                     p2i(this), p2i(prev), p2i(new_value));
+  log_trace(monitorinflation, owner)("set_owner_from(): mid=" INTPTR_FORMAT
+                                     ", prev=" INTPTR_FORMAT ", new="
+                                     INTPTR_FORMAT, p2i(this), p2i(prev),
+                                     p2i(new_value));
 }
 
-// Set _owner field to new_value; current value must match old_value1 or old_value2.
-inline void ObjectMonitor::set_owner_from(void* new_value, void* old_value1, void* old_value2) {
-  void* prev = Atomic::cmpxchg(new_value, &_owner, old_value1);
-  if (prev != old_value1) {
-    prev = Atomic::cmpxchg(new_value, &_owner, old_value2);
-  }
+// Simply set _owner field to new_value; current value must match old_value.
+// (Simple means no memory sync needed.)
+inline void ObjectMonitor::simply_set_owner_from(void* new_value, void* old_value) {
+  void* prev = _owner;
+  ADIM_guarantee(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
+                 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
+  _owner = new_value;
+  log_trace(monitorinflation, owner)("simply_set_owner_from(): mid="
+                                     INTPTR_FORMAT ", prev=" INTPTR_FORMAT
+                                     ", new=" INTPTR_FORMAT, p2i(this),
+                                     p2i(prev), p2i(new_value));
+}
+
+// Simply set _owner field to new_value; current value must match old_value1 or old_value2.
+// (Simple means no memory sync needed.)
+inline void ObjectMonitor::simply_set_owner_from(void* new_value, void* old_value1, void* old_value2) {
+  void* prev = _owner;
   ADIM_guarantee(prev == old_value1 || prev == old_value2,
                  "unexpected prev owner=" INTPTR_FORMAT ", expected1="
                  INTPTR_FORMAT " or expected2=" INTPTR_FORMAT, p2i(prev),
                  p2i(old_value1), p2i(old_value2));
-  log_trace(monitorinflation, owner)("mid=" INTPTR_FORMAT ", prev="
-                                     INTPTR_FORMAT ", new=" INTPTR_FORMAT,
-                                     p2i(this), p2i(prev), p2i(new_value));
+  _owner = new_value;
+  log_trace(monitorinflation, owner)("simply_set_owner_from(old1=" INTPTR_FORMAT
+                                     ", old2=" INTPTR_FORMAT "): mid="
+                                     INTPTR_FORMAT ", prev=" INTPTR_FORMAT
+                                     ", new=" INTPTR_FORMAT, p2i(old_value1),
+                                     p2i(old_value2), p2i(this), p2i(prev),
+                                     p2i(new_value));
 }
 
-// Set _owner field to self; current value must match basic_lock_p.
-inline void ObjectMonitor::set_owner_from_BasicLock(Thread* self, void* basic_lock_p) {
-  assert(self->is_lock_owned((address)basic_lock_p), "self=" INTPTR_FORMAT
-         " must own basic_lock_p=" INTPTR_FORMAT, p2i(self), p2i(basic_lock_p));
+// Simply set _owner field to self; current value must match basic_lock_p.
+inline void ObjectMonitor::simply_set_owner_from_BasicLock(Thread* self, void* basic_lock_p) {
   void* prev = _owner;
   ADIM_guarantee(prev == basic_lock_p, "unexpected prev owner=" INTPTR_FORMAT
                  ", expected=" INTPTR_FORMAT, p2i(prev), p2i(basic_lock_p));
   // Non-null owner field to non-null owner field is safe without
   // cmpxchg() as long as all readers can tolerate either flavor.
   _owner = self;
-  log_trace(monitorinflation, owner)("mid=" INTPTR_FORMAT ", prev="
-                                     INTPTR_FORMAT ", new=" INTPTR_FORMAT,
-                                     p2i(this), p2i(prev), p2i(self));
+  log_trace(monitorinflation, owner)("simply_set_owner_from_BasicLock(): mid="
+                                     INTPTR_FORMAT ", prev=" INTPTR_FORMAT
+                                     ", new=" INTPTR_FORMAT ", basic_lock_p="
+                                     INTPTR_FORMAT, p2i(this), p2i(prev),
+                                     p2i(self), p2i(basic_lock_p));
 }
 
 // Try to set _owner field to new_value if the current value matches
 // old_value. Otherwise, does not change the _owner field.
 inline void* ObjectMonitor::try_set_owner_from(void* new_value, void* old_value) {
   void* prev = Atomic::cmpxchg(new_value, &_owner, old_value);
   if (prev == old_value) {
-    log_trace(monitorinflation, owner)("mid=" INTPTR_FORMAT ", prev="
-                                       INTPTR_FORMAT ", new=" INTPTR_FORMAT,
-                                       p2i(this), p2i(prev), p2i(new_value));
+    log_trace(monitorinflation, owner)("try_set_owner_from(): mid="
+                                       INTPTR_FORMAT ", prev=" INTPTR_FORMAT
+                                       ", new=" INTPTR_FORMAT, p2i(this),
+                                       p2i(prev), p2i(new_value));
   }
   return prev;
 }
 
 inline void ObjectMonitor::set_allocation_state(ObjectMonitor::AllocationState s) {

@@ -181,14 +200,10 @@
 
 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 {

@@ -198,24 +213,26 @@
 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.
-  ADIM_guarantee(AsyncDeflateIdleMonitors || ref_count() >= 0,
-                 "sanity check: ref_count=%d", ref_count());
+  jint l_ref_count = ref_count();
+  ADIM_guarantee(AsyncDeflateIdleMonitors || l_ref_count >= 0,
+                 "sanity check: l_ref_count=%d, ref_count=%d", l_ref_count, 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.
-  ADIM_guarantee(AsyncDeflateIdleMonitors || ref_count() > 0,
-                 "sanity check: ref_count=%d", ref_count());
+  jint l_ref_count = ref_count();
+  ADIM_guarantee(AsyncDeflateIdleMonitors || l_ref_count > 0,
+                 "sanity check: l_ref_count=%d, ref_count=%d", l_ref_count, ref_count());
 }
 
 inline jint ObjectMonitor::ref_count() const {
-  return OrderAccess::load_acquire(&_ref_count);
+  return _ref_count;
 }
 
 #endif // SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP
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