sem_unlink - remove a named semaphore (REALTIME)
#include <semaphore.h> int sem_unlink(const char *name);
The sem_unlink() function removes the semaphore named by the string name. If the semaphore named by name is currently referenced by other processes, then sem_unlink() has 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 re-create or re-connect to the semaphore refer to a new semaphore after sem_unlink() is called. The sem_unlink() call does not block until all references have been destroyed; it returns immediately.
Upon successful completion, the function returns a value of 0. Otherwise, the semaphore is not changed and the function returns a value of -1 and sets errno to indicate the error.
The sem_unlink() function will fail if:
- [EACCES]
- Permission is denied to unlink the named semaphore.
- [ENAMETOOLONG]
- The length of the name string exceeds {NAME_MAX} while {POSIX_NO_TRUNC} is in effect.
- [ENOENT]
- The named semaphore does not exist.
- [ENOSYS]
- The function sem_unlink() is not supported by this implementation.
None.
None.
None.
semctl(), semget(), semop(), sem_close(), sem_open(), <semaphore.h>.
Derived from the POSIX Realtime Extension (1003.1b-1993/1003.1i-1995)