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28.\" $FreeBSD: src/lib/libc_r/man/pthread_schedparam.3,v 1.2.2.5 2001/12/17 10:08:26 ru Exp $
29.\" $DragonFly: src/lib/libc_r/man/pthread_schedparam.3,v 1.2 2003/06/17 04:26:48 dillon Exp $
30.Dd April 15, 2009
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 *policy" "struct sched_param *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) or
54.Dv SCHED_RR
55(round-robin).
56The thread priority (accessed via
57.Va param->sched_priority )
58must be at least
59.Dv PTHREAD_MIN_PRIORITY
60and no more than
61.Dv PTHREAD_MAX_PRIORITY .
62.Sh RETURN VALUES
63If successful, these functions return 0.
64Otherwise, an error number is returned to indicate the error.
65.Sh ERRORS
66.Fn pthread_setschedparam
67will fail if:
68.Bl -tag -width Er
69.It Bq Er EINVAL
70Invalid value for
71.Va policy .
72.It Bq Er ENOTSUP
73Invalid value for scheduling parameters.
74.It Bq Er ESRCH
75Non-existent thread
76.Va thread .
77.El
78.Pp
79.Fn pthread_getschedparam
80will fail if:
81.Bl -tag -width Er
82.It Bq Er ESRCH
83Non-existent thread
84.Va thread .
85.El
86.Sh STANDARDS
87.Fn pthread_setschedparam
88and
89.Fn pthread_getschedparam
90conform to
91.St -susv2
92