.\" $NetBSD: pthread_schedparam.3,v 1.8 2017/07/03 21:32:51 wiz Exp $
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.\" $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 .