src/hotspot/share/runtime/objectMonitor.cpp

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.

*** 858,870 ****
  // then wake a thread unnecessarily. This is benign, and we've
  // structured the code so the windows are short and the frequency
  // of such futile wakups is low.
  
  void ObjectMonitor::exit(bool not_suspended, TRAPS) {
!   Thread * const Self = THREAD;
!   if (THREAD != _owner) {
!     void* cur = _owner;
      if (THREAD->is_lock_owned((address)cur)) {
        assert(_recursions == 0, "invariant");
        set_owner_from_BasicLock(cur, Self);  // Convert from BasicLock* to Thread*.
        _recursions = 0;
      } else {
--- 858,870 ----
  // then wake a thread unnecessarily. This is benign, and we've
  // structured the code so the windows are short and the frequency
  // of such futile wakups is low.
  
  void ObjectMonitor::exit(bool not_suspended, TRAPS) {
!   Thread* const Self = THREAD;
!   void* cur = Atomic::load(&_owner);
!   if (THREAD != cur) {
      if (THREAD->is_lock_owned((address)cur)) {
        assert(_recursions == 0, "invariant");
        set_owner_from_BasicLock(cur, Self);  // Convert from BasicLock* to Thread*.
        _recursions = 0;
      } else {
*** 1118,1129 ****
    assert(Self->is_Java_thread(), "Must be Java thread!");
    JavaThread *jt = (JavaThread *)THREAD;
  
    assert(InitDone, "Unexpectedly not initialized");
  
!   if (THREAD != _owner) {
!     void* cur = _owner;
      if (THREAD->is_lock_owned((address)cur)) {
        assert(_recursions == 0, "internal state error");
        set_owner_from_BasicLock(cur, Self);  // Convert from BasicLock* to Thread*.
        _recursions = 0;
      }
--- 1118,1129 ----
    assert(Self->is_Java_thread(), "Must be Java thread!");
    JavaThread *jt = (JavaThread *)THREAD;
  
    assert(InitDone, "Unexpectedly not initialized");
  
!   void* cur = Atomic::load(&_owner);
!   if (THREAD != cur) {
      if (THREAD->is_lock_owned((address)cur)) {
        assert(_recursions == 0, "internal state error");
        set_owner_from_BasicLock(cur, Self);  // Convert from BasicLock* to Thread*.
        _recursions = 0;
      }
*** 1167,1180 ****
  // Returns true if the specified thread owns the ObjectMonitor.
  // Otherwise returns false and throws IllegalMonitorStateException
  // (IMSE). If there is a pending exception and the specified thread
  // is not the owner, that exception will be replaced by the IMSE.
  bool ObjectMonitor::check_owner(Thread* THREAD) {
!   if (_owner == THREAD) {
      return true;
    }
-   void* cur = _owner;
    if (THREAD->is_lock_owned((address)cur)) {
      set_owner_from_BasicLock(cur, THREAD);  // Convert from BasicLock* to Thread*.
      _recursions = 0;
      return true;
    }
--- 1167,1180 ----
  // Returns true if the specified thread owns the ObjectMonitor.
  // Otherwise returns false and throws IllegalMonitorStateException
  // (IMSE). If there is a pending exception and the specified thread
  // is not the owner, that exception will be replaced by the IMSE.
  bool ObjectMonitor::check_owner(Thread* THREAD) {
!   void* cur = Atomic::load(&_owner);
!   if (cur == THREAD) {
      return true;
    }
    if (THREAD->is_lock_owned((address)cur)) {
      set_owner_from_BasicLock(cur, THREAD);  // Convert from BasicLock* to Thread*.
      _recursions = 0;
      return true;
    }