Interprocess communication

Interprocess communication

UnixWare provides several mechanisms that allow processes to exchange data and synchronize execution. The simpler of these mechanisms are pipes, named pipes, and signals. These are limited, however, in what they can do. For instance,

UnixWare also provides an InterProcess Communication (IPC) package that supports three, more versatile types of interprocess communication. For example,

When implemented as a unit, these three mechanisms share common properties such as

This section describes the system calls for each of these three forms of IPC.

This information is for programmers who write multiprocess applications. These programmers should have a general understanding of what semaphores are and how they are used.

Information from other sources would also be helpful. See ipcs(1) and ipcrm(1), as well as the following manual pages:

intro(2) aclipc(2)

msgget(2) msgctl(2) msgop(2)
semget(2) semctl(2) semop(2)
shmget(2) shmctl(2) shmop(2)

Included in this section are several example programs that show the use of these IPC system calls. Since there are many ways to accomplish the same task or requirement, keep in mind that the example programs were written for clarity and not for program efficiency. Usually, system calls are embedded within a larger user-written program that makes use of a particular function provided by the calls.

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UnixWare 7 Release 7.1.4 - 27 April 2004