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.

*** 65,86 ****
    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;
  }
  
  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));
--- 65,75 ----
    return Atomic::load(&_owner) == DEFLATER_MARKER;
  }
  
  // Returns true if 'this' is being async deflated and false otherwise.
  inline bool ObjectMonitor::is_being_async_deflated() {
!   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));
*** 91,105 ****
  }
  
  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.
      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());
--- 80,94 ----
  }
  
  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; 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());