xref: /netbsd-src/lib/libpthread/pthread_schedparam.3 (revision 01869ca4d24a86379a68731bf9706a9f0820fe4e)

.\" $NetBSD: pthread_schedparam.3,v 1.8 2017/07/03 21:32:51 wiz Exp $
.\"
.\" Copyright (c) 2002 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.\" Copyright (C) 2000 Jason Evans <jasone@FreeBSD.org>.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice(s), this list of conditions and the following disclaimer as
.\"    the first lines of this file unmodified other than the possible
.\"    addition of one or more copyright notices.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice(s), this list of conditions and the following disclaimer in
.\"    the documentation and/or other materials provided with the
.\"    distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD: src/lib/libpthread/man/pthread_schedparam.3,v 1.7 2002/09/16 19:29:29 mini Exp $
.Dd July 9, 2010
.Dt PTHREAD_SCHEDPARAM 3
.Os
.Sh NAME
.Nm pthread_setschedparam ,
.Nm pthread_getschedparam
.Nd thread scheduling parameter manipulation
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_setschedparam "pthread_t thread" "int policy" "const struct sched_param *param"
.Ft int
.Fn pthread_getschedparam "pthread_t thread" "int * restrict policy" "struct sched_param * restrict param"
.Sh DESCRIPTION
The
.Fn pthread_setschedparam
and
.Fn pthread_getschedparam
functions set and get the scheduling parameters of individual threads.
The scheduling policy for a thread can be:
.Bl -tag -width SCHED_OTHER -offset indent
.It Dv SCHED_FIFO
First in, first out.
.It Dv SCHED_RR
Round-robin.
.It Dv SCHED_OTHER
The system default.
.El
.Pp
The thread priority (accessed via
.Va param->sched_priority )
must be at least
.Dv PTHREAD_MIN_PRIORITY
and no more than
.Dv PTHREAD_MAX_PRIORITY .
.Sh RETURN VALUES
If successful, these functions return 0.
Otherwise, an error number is returned to indicate the error.
.Sh ERRORS
.Fn pthread_setschedparam
may fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Va policy
is invalid.
.It Bq Er ENOTSUP
Invalid value for scheduling parameters.
.It Bq Er ESRCH
Non-existent thread
.Va thread .
.El
.Pp
.Fn pthread_getschedparam
may fail if:
.Bl -tag -width Er
.It Bq Er ESRCH
Non-existent thread
.Va thread .
.El
.Sh SEE ALSO
.Xr pthread_attr_getschedparam 3 ,
.Xr sched 3
.Sh STANDARDS
Both functions conform to
.St -p1003.1-2001 .