src/hotspot/share/runtime/objectMonitor.cpp

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.

*** 524,536 ****
      return;
    }
  
    if (AsyncDeflateIdleMonitors &&
        try_set_owner_from(DEFLATER_MARKER, Self) == DEFLATER_MARKER) {
!     // The deflation protocol finished the first part (setting owner),
!     // but it failed the second part (making contentions negative) and
!     // bailed. Acquired the monitor.
      assert(_succ != Self, "invariant");
      assert(_Responsible != Self, "invariant");
      return;
    }
  
--- 524,540 ----
      return;
    }
  
    if (AsyncDeflateIdleMonitors &&
        try_set_owner_from(DEFLATER_MARKER, Self) == DEFLATER_MARKER) {
!     // Cancelled the in-progress async deflation. We bump contentions an
!     // extra time to prevent the async deflater thread from temporarily
!     // changing it to -max_jint and back to zero (no flicker to confuse
!     // is_being_async_deflated()). The async deflater thread will
!     // decrement contentions after it recognizes that the async
!     // deflation was cancelled.
!     add_to_contentions(1);
      assert(_succ != Self, "invariant");
      assert(_Responsible != Self, "invariant");
      return;
    }
  
*** 650,662 ****
  
      if (TryLock(Self) > 0) break;
  
      if (AsyncDeflateIdleMonitors &&
          try_set_owner_from(DEFLATER_MARKER, Self) == DEFLATER_MARKER) {
!       // The deflation protocol finished the first part (setting owner),
!       // but it failed the second part (making contentions negative) and
!       // bailed. Acquired the monitor.
        break;
      }
  
      // The lock is still contested.
      // Keep a tally of the # of futile wakeups.
--- 654,670 ----
  
      if (TryLock(Self) > 0) break;
  
      if (AsyncDeflateIdleMonitors &&
          try_set_owner_from(DEFLATER_MARKER, Self) == DEFLATER_MARKER) {
!       // Cancelled the in-progress async deflation. We bump contentions an
!       // extra time to prevent the async deflater thread from temporarily
!       // changing it to -max_jint and back to zero (no flicker to confuse
!       // is_being_async_deflated()). The async deflater thread will
!       // decrement contentions after it recognizes that the async
!       // deflation was cancelled.
!       add_to_contentions(1);
        break;
      }
  
      // The lock is still contested.
      // Keep a tally of the # of futile wakeups.