At this stage all processes that are not the master subject themselves to receiving a broadcast from the master. This message is the name of the processor the master process runs on. The MPI machine will have done all that. And, if you are a slave process, you are prudent enough to prepare and send a congratulatory message to the master process. Well there is nothing wrong with congratulating yourself.
Some people do it all the time.
Having prepared the message you send it to the master process, and if you are the master process you send it to yourself, which is fine too. Some people seldom receive messages from anyone else. If you are a slave process then this is about all that you are supposed to do in this program, so now you can relax and spin, or go home. But if you are a master process you have to collect all those messages that have been sent to you and print them on standard output in the receive order. The status of the received message should be written on structure status .