inline void ObjectMonitor::DequeueSpecificWaiter(ObjectWaiter* node) {

  {- -------------------------------------------
  (1) (assert)
      ---------------------------------------- -}

      assert(node != NULL, "should not dequeue NULL node");
      assert(node->_prev != NULL, "node already removed from list");
      assert(node->_next != NULL, "node already removed from list");

  {- -------------------------------------------
  (1) 引数で渡された ObjectWaiter (以下の node) を, 
      待ちキュー(_WaitSet)内から削除する.
      ---------------------------------------- -}

      // when the waiter has woken up because of interrupt,
      // timeout or other spurious wake-up, dequeue the
      // waiter from waiting list
      ObjectWaiter* next = node->_next;
      if (next == node) {
        assert(node->_prev == node, "invariant check");
        _WaitSet = NULL;
      } else {
        ObjectWaiter* prev = node->_prev;
        assert(prev->_next == node, "invariant check");
        assert(next->_prev == node, "invariant check");
        next->_prev = prev;
        prev->_next = next;
        if (_WaitSet == node) {
          _WaitSet = next;
        }
      }
      node->_next = NULL;
      node->_prev = NULL;
    }