msgq_id = mq_open( full_queue_name,
O_RDWR | O_CREAT,
S_IRWXU | S_IRWXG,
&msgq_attr);
mq_send(msgq_id, ptrData1, len1, 0);
mq_send(msgq_id, ptrData2, len2, 0);
...
mqd_t open_res = mq_open(full_queue_name, O_RDONLY);
...
mq_receive(...)
mq_receive(...)
... 我能保证消息队列保持消息的顺序吗?