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

rev 57560 : imported patch 8236035.patch.cr0
rev 57561 : dholmes CR - rename simply_set_owner_from() -> set_owner_from() and simply_set_owner_from_BasicLock() -> set_owner_from_BasicLock(); rename release_clear_owner_with_barrier() -> release_clear_owner() and refactor barrier code back into the call sites.
rev 57562 : kbarrett CR - rearrange some loads of _owner field to be more efficient; clarify header comment for try_set_owner_from() declaration; make some loads of _owner field DEBUG_ONLY since they only exist for assert()'s; update related logging calls to use the existing function parameter instead.

@@ -85,45 +85,44 @@
   return _contentions;
 }
 
 // Clear _owner field; current value must match old_value.
 inline void ObjectMonitor::release_clear_owner(void* old_value) {
-  void* prev = _owner;
+  DEBUG_ONLY(void* prev = Atomic::load(&_owner);)
   assert(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
          ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
   Atomic::release_store(&_owner, (void*)NULL);
   log_trace(monitorinflation, owner)("release_clear_owner(): mid="
-                                     INTPTR_FORMAT ", prev=" INTPTR_FORMAT,
-                                     p2i(this), p2i(prev));
+                                     INTPTR_FORMAT ", old_value=" INTPTR_FORMAT,
+                                     p2i(this), p2i(old_value));
 }
 
 // Simply set _owner field to new_value; current value must match old_value.
 // (Simple means no memory sync needed.)
 inline void ObjectMonitor::set_owner_from(void* old_value, void* new_value) {
-  void* prev = _owner;
+  DEBUG_ONLY(void* prev = Atomic::load(&_owner);)
   assert(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
          ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
-  _owner = new_value;
+  Atomic::store(&_owner, 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));
+                                     INTPTR_FORMAT ", old_value=" INTPTR_FORMAT
+                                     ", new_value=" INTPTR_FORMAT, p2i(this),
+                                     p2i(old_value), p2i(new_value));
 }
 
 // Simply set _owner field to self; current value must match basic_lock_p.
 inline void ObjectMonitor::set_owner_from_BasicLock(void* basic_lock_p, Thread* self) {
-  void* prev = _owner;
+  DEBUG_ONLY(void* prev = Atomic::load(&_owner);)
   assert(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;
+  Atomic::store(&_owner, self);
   log_trace(monitorinflation, owner)("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));
+                                     INTPTR_FORMAT ", basic_lock_p="
+                                     INTPTR_FORMAT ", new_value=" INTPTR_FORMAT,
+                                     p2i(this), p2i(basic_lock_p), p2i(self));
 }
 
 // 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* old_value, void* new_value) {