Method enqueue_nowait

kernel/oswrapper/vspace.h:1081–1088

  friend class DequeueEvent;

  void enqueue_nowait(T item) {
    _lock.lock();
    VRef<Node> node = vnew<Node>();
    node->data = item;
    push(node);
    _lock.unlock();
    _incoming.post();
  }
  T dequeue_nowait() {
    _lock.lock();
    VRef<Node> node = pop();