Unix™ Systems Programming: Communication, Concurrency, and Threads

Chapter 15. POSIX IPC

The classical UNIX interprocess communication (IPC) mechanisms of shared memory, message queues and semaphore sets are standardized in the POSIX:XSI Extension. These mechanisms, which allow unrelated processes to exchange information in a reasonably efficient way, use a key to identify, create or access the corresponding entity. The entities may persist in the system beyond the lifetime of the process that creates them, but conveniently, POSIX:XSI also provides shell commands to list and remove them.

Objectives

• Learn about classical interprocess communication

• Experiment with synchronized shared memory

• Explore semaphore implementations

• Use message queues for interprocess logging

• Understand the consequences of persistence

POSIX:XSI ...