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.\" $FreeBSD: head/share/man/man3/pthread_rwlockattr_setpshared.3 301077 2016-05-31 21:16:34Z jilles $
.\"
.Dd May 31, 2016
.Dt PTHREAD_RWLOCKATTR_SETPSHARED 3
.Os
.Sh NAME
.Nm pthread_rwlockattr_setpshared
.Nd set the process shared attribute
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_rwlockattr_setpshared "pthread_rwlockattr_t *attr" "int pshared"
.Sh DESCRIPTION
The
.Fn pthread_rwlockattr_setpshared
function sets the process shared attribute of
.Fa attr
to the value referenced by
.Fa pshared .
The
.Fa pshared
argument may be one of two values:
.Bl -tag -width PTHREAD_PROCESS_PRIVATE
.It Dv PTHREAD_PROCESS_SHARED
Any thread of any process that has access to the memory where the
read/write lock resides can manipulate the lock.
.It Dv PTHREAD_PROCESS_PRIVATE
Only threads created within the same process as the thread that
initialized the read/write lock can manipulate the lock.
This is
the default value.
.El
.Sh RETURN VALUES
If successful, the
.Fn pthread_rwlockattr_setpshared
function will return zero.
Otherwise an error number will be returned
to indicate the error.
.Sh ERRORS
The
.Fn pthread_rwlockattr_setpshared
function will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa attr
or
.Fa pshared
is invalid.
.El
.Sh SEE ALSO
.Xr pthread_rwlock_init 3 ,
.Xr pthread_rwlockattr_getpshared 3 ,
.Xr pthread_rwlockattr_init 3
.Sh STANDARDS
The
.Fn pthread_rwlockattr_setpshared
function is expected to conform to
.St -susv2 .
.Sh HISTORY
The
.Fn pthread_rwlockattr_setpshared
function first appeared in
.Fx 3.0 .
Support for process-shared read/write locks appeared in
.Fx 11.0 .