sem_destroy - destroy an unnamed semaphore (REALTIME)
#include <semaphore.h> int sem_destroy(sem_t *sem);
The sem_destroy() function is used to destroy the unnamed semaphore indicated by sem. Only a semaphore that was created using sem_init() 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-initialised by another call to sem_init().
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.
Upon successful completion, a value of zero is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.
The sem_destroy() function will fail if:
- The sem argument is not a valid semaphore.
- The function sem_destroy() is not supported by this implementation.
The sem_destroy() function may fail if:
- There are currently processes blocked on the semaphore.
semctl(), semget(), semop(), sem_init(), sem_open(), <semaphore.h>.
Derived from the POSIX Realtime Extension (1003.1b-1993/1003.1i-1995)