47.1. Overview

The general steps for using a System V semaphore are the following:

• Create or open a semaphore set using semget().

• Initialize the semaphores in the set using the semctl() SETVAL or SETALL operation. (Only one process should do this.)

• Perform operations on semaphore values using semop(). The processes using the semaphore typically use these operations to indicate acquisition and release of a shared resource.

• When all processes have finished using the semaphore set, remove the set using the semctl() IPC_RMID operation. (Only one process should do this.)