freebsd-nq/lib/libc/gen/sem_destroy.3

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.Dd February 15, 2000
.Dt SEM_DESTROY 3
.Os
.Sh NAME
.Nm sem_destroy
.Nd destroy an unnamed semaphore
.Sh LIBRARY
.Lb libc
.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
.Xr sem_init 3 .
.Sh RETURN VALUES
.Rv -std sem_destroy
.Sh ERRORS
The
.Fn sem_destroy
function will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The
.Fa sem
argument
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 ,
.Xr sem 4
.Sh STANDARDS
The
.Fn sem_destroy
function conforms to
.St -p1003.1-96 .
.Pp
.Tn 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 .