src/hotspot/share/oops/klass.cpp

*** 408,418 ****
  void Klass::set_next_sibling(Klass* s) {
    assert(s != this, "sanity check");
    // Does not need release semantics. If used by cleanup, it will link to
    // already safely published data, and if used by inserts, will be published
    // safely using cmpxchg.
!   Atomic::store(s, &_next_sibling);
  }
  
  void Klass::append_to_sibling_list() {
    assert_locked_or_safepoint(Compile_lock);
    debug_only(verify();)
--- 408,418 ----
  void Klass::set_next_sibling(Klass* s) {
    assert(s != this, "sanity check");
    // Does not need release semantics. If used by cleanup, it will link to
    // already safely published data, and if used by inserts, will be published
    // safely using cmpxchg.
!   Atomic::store(&_next_sibling, s);
  }
  
  void Klass::append_to_sibling_list() {
    assert_locked_or_safepoint(Compile_lock);
    debug_only(verify();)
*** 434,444 ****
        set_next_sibling(prev_first_subklass);
      }
      // Note that the prev_first_subklass is always alive, meaning no sibling_next links
      // are ever created to not alive klasses. This is an important invariant of the lock-free
      // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list.
!     if (Atomic::cmpxchg(this, &super->_subklass, prev_first_subklass) == prev_first_subklass) {
        return;
      }
    }
    debug_only(verify();)
  }
--- 434,444 ----
        set_next_sibling(prev_first_subklass);
      }
      // Note that the prev_first_subklass is always alive, meaning no sibling_next links
      // are ever created to not alive klasses. This is an important invariant of the lock-free
      // cleaning protocol, that allows us to safely unlink dead klasses from the sibling list.
!     if (Atomic::cmpxchg(&super->_subklass, prev_first_subklass, this) == prev_first_subklass) {
        return;
      }
    }
    debug_only(verify();)
  }
*** 449,459 ****
      Klass* subklass = Atomic::load_acquire(&_subklass);
      if (subklass == NULL || subklass->is_loader_alive()) {
        return;
      }
      // Try to fix _subklass until it points at something not dead.
!     Atomic::cmpxchg(subklass->next_sibling(), &_subklass, subklass);
    }
  }
  
  void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
    if (!ClassUnloading || !unloading_occurred) {
--- 449,459 ----
      Klass* subklass = Atomic::load_acquire(&_subklass);
      if (subklass == NULL || subklass->is_loader_alive()) {
        return;
      }
      // Try to fix _subklass until it points at something not dead.
!     Atomic::cmpxchg(&_subklass, subklass, subklass->next_sibling());
    }
  }
  
  void Klass::clean_weak_klass_links(bool unloading_occurred, bool clean_alive_klasses) {
    if (!ClassUnloading || !unloading_occurred) {
*** 708,718 ****
  jint Klass::compute_modifier_flags(TRAPS) const {
    return 0;
  }
  
  int Klass::atomic_incr_biased_lock_revocation_count() {
!   return (int) Atomic::add(1, &_biased_lock_revocation_count);
  }
  
  // Unless overridden, jvmti_class_status has no flags set.
  jint Klass::jvmti_class_status() const {
    return 0;
--- 708,718 ----
  jint Klass::compute_modifier_flags(TRAPS) const {
    return 0;
  }
  
  int Klass::atomic_incr_biased_lock_revocation_count() {
!   return (int) Atomic::add(&_biased_lock_revocation_count, 1);
  }
  
  // Unless overridden, jvmti_class_status has no flags set.
  jint Klass::jvmti_class_status() const {
    return 0;