sem_unlink - remove a named semaphore (REALTIME)
[SEM] #include <semaphore.h>
int sem_unlink(const char *name);
The sem_unlink() function shall remove the semaphore named by the string name. If the semaphore named by name is currently referenced by other processes, then sem_unlink() shall have no effect on the state of the semaphore. If one or more processes have the semaphore open when sem_unlink() is called, destruction of the semaphore is postponed until all references to the semaphore have been destroyed by calls to sem_close(), _exit(), or exec. Calls to sem_open() to recreate or reconnect to the semaphore refer to a new semaphore after sem_unlink() is called. The sem_unlink() call shall not block until all references have been destroyed; it shall return immediately.
Upon successful completion, the sem_unlink() function shall return a value of 0. Otherwise, the semaphore shall not be changed and the function shall return a value of -1 and set errno to indicate the error.
The sem_unlink() function shall fail if:
- [EACCES]
- Permission is denied to unlink the named semaphore.
- [ENAMETOOLONG]
- The length of the name argument exceeds {PATH_MAX} or a pathname component is longer than {NAME_MAX}.
- [ENOENT]
- The named semaphore does not exist.
None.
The sem_unlink() function is part of the Semaphores option and need not be available on all implementations.
None.
None.
semctl(), semget(), semop() , sem_close(), sem_open(), the Base Definitions volume of IEEE Std 1003.1-2001, <semaphore.h>
First released in Issue 5. Included for alignment with the POSIX Realtime Extension.
The sem_unlink() function is marked as part of the Semaphores option.
The [ENOSYS] error condition has been removed as stubs need not be provided if an implementation does not support the Semaphores option.