NAME

       sem_destroy - destroy an unnamed semaphore (REALTIME)

SYNOPSIS

       #include <semaphore.h>

       int sem_destroy(sem_t *sem);

DESCRIPTION

       The  sem_destroy()  function  shall 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 reinitialized by another call to sem_init().

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

RETURN VALUE

       Upon successful completion, a value of zero shall be returned. Otherwise, a value of -1 shall be returned
       and errno set to indicate the error.

ERRORS

       The sem_destroy() function shall fail if:

       EINVAL The sem argument is not a valid semaphore.

       The sem_destroy() function may fail if:

       EBUSY  There are currently processes blocked on the semaphore.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       The  sem_destroy()  function  is  part  of  the  Semaphores  option  and  need  not  be  available on all
       implementations.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       semctl()  ,  semget()  ,  semop()  ,  sem_init()  ,  sem_open()  ,  the  Base   Definitions   volume   of
       IEEE Std 1003.1-2001, <semaphore.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
       Inc and The Open Group. In the event of any discrepancy between this version and the  original  IEEE  and
       The  Open  Group  Standard,  the  original  IEEE and The Open Group Standard is the referee document. The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                                   2003                                        SEM_DESTROY(P)