Skip to main content

Beej's Guide to Unix Interprocess Communication.

You know what's easy? fork() is easy. You can fork off new processes all day and have them deal with individual chunks of a problem in parallel. Of course, its easiest if the processes don't have to communicate with one another while they're running and can just sit there doing their own thing.

However, when you start fork()'ing processes, you immediately start to think of the neat multi-user things you could do if the processes could talk to each other easily. So you try making a global array and then fork()'ing to see if it is shared. (That is, see if both the child and parent process use the same array.) Soon, of course, you find that the child process has its own copy of the array and the parent is oblivious to whatever changes the child makes to it.

How do you get these guys to talk to one another, share data structures, and be generally amicable? This document discusses several methods of Interprocess Communication (IPC) that can accomplish this, some of which are better suited to certain tasks than others.

Comments

Popular posts from this blog

Debugging Perl

The standard Perl distribution comes with a debugger, although it's really just another Perl program, perl5db.pl. Since it is just a program, I can use it as the basis for writing my own debuggers to suit my needs, or I can use the interface perl5db.pl provides to configure its actions. That's just the beginning, though. read more...

How To Set Up A Cisco Lab On Linux

After a quick search I found the wonderful Dynamips project that goes beyond what other simulators do by running actual Cisco IOS images, as well as the PEMU project which allows for running of Cisco PIX images. To integrate the various pieces of software... more .