SEM_DESTROY(3P)                                     POSIX Programmer's Manual                                    SEM_DESTROY(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

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,  Copy-
       right (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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                               SEM_DESTROY(3P)