Deallocates the specified named semaphore.

    This function is supported on OpenVMS Integrity servers and
    Alpha only.

    Format

      #include  <semaphore.h>

      int sem_close  (sem_t *sem);

1 - Argument

 sem

    The semaphore to be closed. Use the sem argument returned by the
    previous call to sem_open.

2 - Description

    The sem_close function makes a semaphore available for reuse
    by deallocating any system resources allocated for use by the
    current process for the named semaphore indicated by sem.

    If the semaphore has not been removed with a call to sem_unlink,
    sem_close does not change the current state of the semaphore.

    If the semaphore has been removed with a call to sem_unlink after
    the most recent call to sem_open with O_CREAT, the semaphore is
    no longer available after all processes that opened the semaphore
    close it.

3 - Return Values

    0                  Successful completion.
    -1                 Indicates an error. The function sets errno to
                       one of the following values:

                       o  EINVAL - The sem argument is not a valid
                          semaphore descriptor.

                       o  ENOSYS - The function is not implemented.

                       o  EVMSERR - OpenVMS specific nontranslatable
                          error code.