I have an app just after kernal boot up. I use message queue in it. If I call mq_open() right away in my app, it shows " mq_open(): Function not implemented". If put sleep(1) before mq_open(), then it is fine.
As my understanding, mq_open(…,“my_mq_name”,…) will create a path /dev/mqueue/my_mq_name. Just like file open() and create a file descriptor.
Questions: Is there any procondition or dependence for using mq?