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.\" $FreeBSD: src/lib/libc_r/man/sem_destroy.3,v 1.1.2.8 2002/12/29 16:35:35 schweikh Exp $
.\" $DragonFly: src/lib/libc_r/man/sem_destroy.3,v 1.2 2003/06/17 04:26:48 dillon Exp $
.Dd April 15, 2009
.Dt SEM_DESTROY 3
.Os
.Sh NAME
.Nm sem_destroy
.Nd destroy an unnamed semaphore
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In semaphore.h
.Ft int
.Fn sem_destroy "sem_t *sem"
.Sh DESCRIPTION
The
.Fn sem_destroy
function destroys the unnamed semaphore pointed to by
.Fa sem .
After a successful call to
.Fn sem_destroy ,
.Fa sem
is unusable until re-initialized by another call to
.Fn sem_init .
.Sh RETURN VALUES
.Rv -std sem_destroy
.Sh ERRORS
.Fn sem_destroy
will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
.Fa sem
points to an invalid semaphore.
.It Bq Er EBUSY
There are currently threads blocked on the semaphore that
.Fa sem
points to.
.El
.Sh SEE ALSO
.Xr sem_init 3
.Sh STANDARDS
.Fn sem_destroy
conforms to
.St -p1003.1-96 .
.Pp
POSIX does not define the behavior of
.Fn sem_destroy
if called while there are threads blocked on
.Fa sem ,
but this implementation is guaranteed to return -1 and set
.Va errno
to
.Er EBUSY
if there are threads blocked on
.Fa sem .