push

static VALUE
rb_szqueue_push(int argc, VALUE *argv, VALUE self)
{
    struct waiting_delete args;
    int should_block = szqueue_push_should_block(argc, argv);
    args.waiting = GET_SZQUEUE_WAITERS(self);
    args.th      = rb_thread_current();

    while (queue_length(self) >= GET_SZQUEUE_ULONGMAX(self)) {
        if (!should_block) {
            rb_raise(rb_eThreadError, "queue full");
        }
        else if (queue_closed_p(self)) {
            goto closed;
        }
        else {
            rb_ary_push(args.waiting, args.th);
            rb_ensure(queue_sleep, Qfalse, queue_delete_from_waiting, (VALUE)&args);
        }
    }

    if (queue_closed_p(self)) {
      closed:
        raise_closed_queue_error(self);
    }

    return queue_do_push(self, argv[0]);
}