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

rev 59376 : 8153224.v2.10.patch merged with 8153224.v2.11.patch.
rev 59377 : CR1 changes from dcubed, dholmes, eosterlund and rehn.
rev 59378 : CR changes from dholmes, dcubed; fix is_being_async_deflated() race found by eosterlund; WB_ForceSafepoint() should request a special clean up with AsyncDeflateIdleMonitors; add a barrier in install_displaced_markword_in_object() to separate the header load from the preceding loads in is_being_async_deflated().
rev 59379 : eosterlund CR - Switch from three part async deflation protocol to a two part async deflation protocol where a negative contentions field is a linearization point.

@@ -65,22 +65,11 @@
   return Atomic::load(&_owner) == DEFLATER_MARKER;
 }
 
 // Returns true if 'this' is being async deflated and false otherwise.
 inline bool ObjectMonitor::is_being_async_deflated() {
-  if (AsyncDeflateIdleMonitors &&
-      // Check first part of the async deflation dance:
-      owner_is_DEFLATER_MARKER() &&
-      // Check second part of the async deflation dance:
-      contentions() < 0 &&
-      // Check third part of the async deflation dance, i.e., the
-      // owner field is still DEFLATER_MARKER:
-      owner_is_DEFLATER_MARKER()
-     ) {
-    return true;
-  }
-  return false;
+  return AsyncDeflateIdleMonitors && contentions() < 0;
 }
 
 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));

@@ -91,15 +80,15 @@
 }
 
 inline void ObjectMonitor::clear_common() {
   if (AsyncDeflateIdleMonitors) {
     // Async deflation protocol uses the header, owner and contentions
-    // fields. While the ObjectMonitor being deflated is on the global free
-    // list, we leave those three fields alone; owner == DEFLATER_MARKER
-    // and contentions < 0 will force any racing threads to retry. The
-    // header field is used by install_displaced_markword_in_object()
-    // to restore the object's header so we cannot check its value here.
+    // fields. While the ObjectMonitor being deflated is on the global
+    // free list, we leave those three fields alone; contentions < 0
+    // will force any racing threads to retry. The header field is used
+    // by install_displaced_markword_in_object() to restore the object's
+    // header so we cannot check its value here.
     guarantee(_owner == NULL || _owner == DEFLATER_MARKER,
               "must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT,
               p2i(_owner));
   }
   assert(contentions() <= 0, "must not be positive: contentions=%d", contentions());