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.Dd October 17, 2022 29.Dt PTHREAD_SCHEDPARAM 3 30.Os 31.Sh NAME 32.Nm pthread_setschedparam , 33.Nm pthread_getschedparam 34.Nd thread scheduling parameter manipulation 35.Sh LIBRARY 36.Lb libpthread 37.Sh SYNOPSIS 38.In pthread.h 39.Ft int 40.Fn pthread_setschedparam "pthread_t thread" "int policy" "const struct sched_param *param" 41.Ft int 42.Fn pthread_getschedparam "pthread_t thread" "int *restrict policy" "struct sched_param *restrict param" 43.Sh DESCRIPTION 44The 45.Fn pthread_setschedparam 46and 47.Fn pthread_getschedparam 48functions set and get the scheduling parameters of individual threads. 49The scheduling policy for a thread can either be 50.Dv SCHED_FIFO 51(first in, first out), 52.Dv SCHED_RR 53(round-robin), or 54.Dv SCHED_OTHER 55(timesharing). 56Valid thread priorities (accessed via 57.Va param->sched_priority ) 58must be within the range returned by the 59.Xr sched_get_priority_min 2 60and 61.Xr sched_get_priority_max 2 62system calls. 63.Sh RETURN VALUES 64If successful, these functions return 0. 65Otherwise, an error number is returned to indicate the error. 66.Sh ERRORS 67The 68.Fn pthread_setschedparam 69function will fail if: 70.Bl -tag -width Er 71.It Bq Er EINVAL 72Invalid value for 73.Fa policy . 74.It Bq Er ENOTSUP 75Invalid value for scheduling parameters. 76.It Bq Er EPERM 77The calling thread does not have sufficient privilege to perform the operation. 78.It Bq Er ESRCH 79Non-existent thread 80.Fa thread . 81.El 82.Pp 83The 84.Fn pthread_getschedparam 85function will fail if: 86.Bl -tag -width Er 87.It Bq Er ESRCH 88Non-existent thread 89.Fa thread . 90.El 91.Sh SEE ALSO 92.Xr sched_get_priority_max 2 , 93.Xr sched_get_priority_min 2 94.Sh STANDARDS 95The 96.Fn pthread_setschedparam 97and 98.Fn pthread_getschedparam 99functions conform to 100.St -susv2 . 101