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.TH PTHREAD_ATTR_SETSCHEDPARAM 3 2013-06-21 "Linux" "Linux Programmer's Manual"
.SH NAME
pthread_attr_setschedparam, pthread_attr_getschedparam \- set/get
scheduling parameter attributes in thread attributes object
.SH SYNOPSIS
.nf
.B #include <pthread.h>

.BI "int pthread_attr_setschedparam(pthread_attr_t *" attr ,
.BI "                               const struct sched_param *" param );
.BI "int pthread_attr_getschedparam(pthread_attr_t *" attr ,
.BI "                               struct sched_param *" param );
.sp
Compile and link with \fI\-pthread\fP.
.fi
.SH DESCRIPTION
The
.BR pthread_attr_setschedparam ()
function sets the scheduling parameter attributes of the
thread attributes object referred to by
.IR attr
to the values specified in the buffer pointed to by
.IR param .
These attributes determine the scheduling parameters of
a thread created using the thread attributes object
.IR attr .

The
.BR pthread_attr_getschedparam ()
returns the scheduling parameter attributes of the thread attributes object
.IR attr
in the buffer pointed to by
.IR param .

Scheduling parameters are maintained in the following structure:

.in +4n
.nf
struct sched_param {
    int sched_priority;     /* Scheduling priority */
};
.fi
.in

As can be seen, only one scheduling parameter is supported.
For details of the permitted ranges for scheduling priorities
in each scheduling policy, see
.BR sched_setscheduler (2).

In order for the parameter setting made by
.BR pthread_attr_setschedparam ()
to have effect when calling
.BR pthread_create (3),
the caller must use
.BR pthread_attr_setinheritsched (3)
to set the inherit-scheduler attribute of the attributes object
.I attr
to
.BR PTHREAD_EXPLICIT_SCHED .
.SH RETURN VALUE
On success, these functions return 0;
on error, they return a nonzero error number.
.SH ERRORS
POSIX.1 documents
.B EINVAL
and
.B ENOTSUP
errors for
.BR pthread_attr_setschedparam ().
On Linux these functions always succeed
(but portable and future-proof applications should nevertheless
handle a possible error return).
.\" .SH VERSIONS
.\" Available since glibc 2.0.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbw29 lb lb
l l l.
Interface	Attribute	Value
T{
.BR pthread_attr_setschedparam (),
.BR pthread_attr_getschedparam ()
T}	Thread safety	MT-Safe
.TE
.SH CONFORMING TO
POSIX.1-2001.
.SH NOTES
See
.BR pthread_attr_setschedpolicy (3)
for a list of the thread scheduling policies supported on Linux.
.SH EXAMPLE
See
.BR pthread_setschedparam (3).
.SH SEE ALSO
.ad l
.nh
.BR sched_get_priority_min (2),
.BR sched_setscheduler (2),
.BR pthread_attr_init (3),
.BR pthread_attr_setinheritsched (3),
.BR pthread_attr_setschedpolicy (3),
.BR pthread_create (3),
.BR pthread_setschedparam (3),
.BR pthread_setschedprio (3),
.BR pthreads (7)
.SH COLOPHON
This page is part of release 3.53 of the Linux
.I man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
\%http://www.kernel.org/doc/man\-pages/.
