multiprocessing question

[kiros88]

well i'm sorta new to muliprocessing to the point were i can use fork() two different ways. One way is to have one main program and have it fork to do different processes. The second way is to have 2 mains and one process just forks into the second main process have both mains run simutaneously. But I wanted to use the second method with two mains, but I dont know how to interproccess communicate the info to each other like if i was sending in an array from one process to another how to do this.

[MK27]

"Interprocess communication" is something you have to set up between the processes, using a pipe or socket to send messages back and forth.

If you want to share variable directly, you need to use the pthread library or something similar.

[brewbuck]

well i'm sorta new to muliprocessing to the point were i can use fork() two different ways. One way is to have one main program and have it fork to do different processes. The second way is to have 2 mains and one process just forks into the second main process have both mains run simutaneously. But I wanted to use the second method with two mains, but I dont know how to interproccess communicate the info to each other like if i was sending in an array from one process to another how to do this.

If the two processes are going to communicate a lot, you should consider using threads instead of separate processes. If processes are really what you want, the usual way of communicating data between them is pipes.

[sean]

You can use pipes (there are various types), shared memory, signals, etc... What method you use depends on your needs. I learned from this tutorial, and other references are abundant: 6 Linux Interprocess Communications

[kiros88]

Well I'm developing a network program so I'm not really sure if two processes are better then threads but I just thought since I have a seperate process taking in network frames and then a seperate one using the frame for its own application would it be smarter to just do that all in one process with multiple threads?

[bithub]

If I understand you correctly, then yes it would be better to use 1 process with multiple threads. You have 1 thread receiving packets of the wire, and another thread processing those packets. It's a pretty common design pattern if you are not using non-blocking sockets or select().