The sem_destroy() function is used to destroy the unnamed semaphore indicated by sem. Only a semaphore that was created using sem_init(3RT) may be destroyed using sem_destroy(); the effect of calling sem_destroy() with a named semaphore is undefined. The effect of subsequent use of the semaphore sem is undefined until sem is re-initialized by another call to sem_init(3RT).

It is safe to destroy an initialised semaphore upon which no threads are currently blocked. The effect of destroying a semaphore upon which other threads are currently blocked is undefined.

If successful, sem_destroy() returns 0, otherwise it returns -1 and sets errno to indicate the error.

The sem_destroy() function will fail if:

EINVAL

The sem argument is not a valid semaphore.

ENOSYS

The sem_destroy() function is not supported by the system.

The sem_destroy() function may fail if:

EBUSY

There are currently processes (or LWPs or threads) blocked on the semaphore.

See attributes(5) for descriptions of the following attributes:

sem_init(3RT), sem_open(3RT), attributes(5)