1.\" Copyright (C) 2000 Jason Evans <jasone@FreeBSD.org>. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as 9.\" the first lines of this file unmodified other than the possible 10.\" addition of one or more copyright notices. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice(s), this list of conditions and the following disclaimer in 13.\" the documentation and/or other materials provided with the 14.\" distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 17.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE 20.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 23.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 24.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 25.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 26.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27.\" 28.\" $FreeBSD$ 29.\" 30.Dd October 17, 2022 31.Dt PTHREAD_SCHEDPARAM 3 32.Os 33.Sh NAME 34.Nm pthread_setschedparam , 35.Nm pthread_getschedparam 36.Nd thread scheduling parameter manipulation 37.Sh LIBRARY 38.Lb libpthread 39.Sh SYNOPSIS 40.In pthread.h 41.Ft int 42.Fn pthread_setschedparam "pthread_t thread" "int policy" "const struct sched_param *param" 43.Ft int 44.Fn pthread_getschedparam "pthread_t thread" "int *restrict policy" "struct sched_param *restrict param" 45.Sh DESCRIPTION 46The 47.Fn pthread_setschedparam 48and 49.Fn pthread_getschedparam 50functions set and get the scheduling parameters of individual threads. 51The scheduling policy for a thread can either be 52.Dv SCHED_FIFO 53(first in, first out), 54.Dv SCHED_RR 55(round-robin), or 56.Dv SCHED_OTHER 57(timesharing). 58Valid thread priorities (accessed via 59.Va param->sched_priority ) 60must be within the range returned by the 61.Xr sched_get_priority_min 2 62and 63.Xr sched_get_priority_max 2 64system calls. 65.Sh RETURN VALUES 66If successful, these functions return 0. 67Otherwise, an error number is returned to indicate the error. 68.Sh ERRORS 69The 70.Fn pthread_setschedparam 71function will fail if: 72.Bl -tag -width Er 73.It Bq Er EINVAL 74Invalid value for 75.Fa policy . 76.It Bq Er ENOTSUP 77Invalid value for scheduling parameters. 78.It Bq Er EPERM 79The calling thread does not have sufficient privilege to perform the operation. 80.It Bq Er ESRCH 81Non-existent thread 82.Fa thread . 83.El 84.Pp 85The 86.Fn pthread_getschedparam 87function will fail if: 88.Bl -tag -width Er 89.It Bq Er ESRCH 90Non-existent thread 91.Fa thread . 92.El 93.Sh SEE ALSO 94.Xr sched_get_priority_max 2 , 95.Xr sched_get_priority_min 2 96.Sh STANDARDS 97The 98.Fn pthread_setschedparam 99and 100.Fn pthread_getschedparam 101functions conform to 102.St -susv2 . 103