src/hotspot/share/runtime/objectMonitor.cpp

rev 54572 : Checkpoint latest preliminary review patches for full OpenJDK review; merge with 8222295.patch.
rev 54573 : imported patch dcubed.monitor_deflate_conc.v2.01
rev 54574 : imported patch dcubed.monitor_deflate_conc.v2.02

*** 2097,2113 ****
    if (AsyncDeflateIdleMonitors) {
      // Race here if monitor is not owned! The above ref_count bump
      // will cause subsequent async deflation to skip it. However,
      // previous or concurrent async deflation is a race.
      if (om_ptr->_owner == DEFLATER_MARKER && om_ptr->_contentions <= 0) {
!       // Async deflation is in progress. Attempt to restore the
!       // header/dmw to the object's header so that we only retry once
!       // if the deflater thread happens to be slow.
        om_ptr->install_displaced_markword_in_object(object);
        om_ptr->dec_ref_count();
        return false;
      }
      // The ObjectMonitor could have been deflated and reused for
      // another object before we bumped the ref_count so make sure
      // our object still refers to this ObjectMonitor.
      const markOop tmp = object->mark();
      if (!tmp->has_monitor() || tmp->monitor() != om_ptr) {
--- 2097,2117 ----
    if (AsyncDeflateIdleMonitors) {
      // Race here if monitor is not owned! The above ref_count bump
      // will cause subsequent async deflation to skip it. However,
      // previous or concurrent async deflation is a race.
      if (om_ptr->_owner == DEFLATER_MARKER && om_ptr->_contentions <= 0) {
!       // Async deflation is in progress.
!       if (om_ptr->ref_count() <= 0) {
!         // And our ref_count increment above lost the race to async
!         // deflation. Attempt to restore the header/dmw to the
!         // object's header so that we only retry once if the deflater
!         // thread happens to be slow.
          om_ptr->install_displaced_markword_in_object(object);
          om_ptr->dec_ref_count();
          return false;
        }
+     }
      // The ObjectMonitor could have been deflated and reused for
      // another object before we bumped the ref_count so make sure
      // our object still refers to this ObjectMonitor.
      const markOop tmp = object->mark();
      if (!tmp->has_monitor() || tmp->monitor() != om_ptr) {