man-pages/man3/pthread_attr_setschedparam.3.html
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<H1>PTHREAD_ATTR_SETSCHEDPARAM</H1>
Section: Linux Programmer's Manual (3)<BR>Updated: 2017-09-15<BR><A HREF="#index">Index</A>
<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>
pthread_attr_setschedparam, pthread_attr_getschedparam - set/get
scheduling parameter attributes in thread attributes object
<A NAME="lbAC">&nbsp;</A>
<H2>SYNOPSIS</H2>
<PRE>
<B>#include &lt;<A HREF="file:///usr/include/pthread.h">pthread.h</A>&gt;</B>
<B>int pthread_attr_setschedparam(pthread_attr_t *</B><I>attr</I><B>,</B>
<B> const struct sched_param *</B><I>param</I><B>);</B>
<B>int pthread_attr_getschedparam(const pthread_attr_t *</B><I>attr</I><B>,</B>
<B> struct sched_param *</B><I>param</I><B>);</B>
Compile and link with <I>-pthread</I>.
</PRE>
<A NAME="lbAD">&nbsp;</A>
<H2>DESCRIPTION</H2>
The
<B>pthread_attr_setschedparam</B>()
function sets the scheduling parameter attributes of the
thread attributes object referred to by
<I>attr</I>
to the values specified in the buffer pointed to by
<I>param</I>.
These attributes determine the scheduling parameters of
a thread created using the thread attributes object
<I>attr</I>.
<P>
The
<B>pthread_attr_getschedparam</B>()
returns the scheduling parameter attributes of the thread attributes object
<I>attr</I>
in the buffer pointed to by
<I>param</I>.
<P>
Scheduling parameters are maintained in the following structure:
<P>
struct sched_param {
<BR>&nbsp;&nbsp;&nbsp;&nbsp;int&nbsp;sched_priority;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;/*&nbsp;Scheduling&nbsp;priority&nbsp;*/
};
<P>
As can be seen, only one scheduling parameter is supported.
For details of the permitted ranges for scheduling priorities
in each scheduling policy, see
<B><A HREF="/cgi-bin/man/man2html?7+sched">sched</A></B>(7).
<P>
In order for the parameter setting made by
<B>pthread_attr_setschedparam</B>()
to have effect when calling
<B><A HREF="/cgi-bin/man/man2html?3+pthread_create">pthread_create</A></B>(3),
the caller must use
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_setinheritsched">pthread_attr_setinheritsched</A></B>(3)
to set the inherit-scheduler attribute of the attributes object
<I>attr</I>
to
<B>PTHREAD_EXPLICIT_SCHED</B>.
<A NAME="lbAE">&nbsp;</A>
<H2>RETURN VALUE</H2>
On success, these functions return 0;
on error, they return a nonzero error number.
<A NAME="lbAF">&nbsp;</A>
<H2>ERRORS</H2>
<B>pthread_attr_setschedparam</B>()
can fail with the following error:
<DL COMPACT>
<DT id="1"><B>EINVAL</B>
<DD>
The priority specified in
<I>param</I>
does not make sense for the current scheduling policy of
<I>attr</I>.
</DL>
<P>
POSIX.1 also documents an
<B>ENOTSUP</B>
error for
<B>pthread_attr_setschedparam</B>().
This value is never returned on Linux
(but portable and future-proof applications should nevertheless
handle this error return value).
<A NAME="lbAG">&nbsp;</A>
<H2>ATTRIBUTES</H2>
For an explanation of the terms used in this section, see
<B><A HREF="/cgi-bin/man/man2html?7+attributes">attributes</A></B>(7).
<TABLE BORDER>
<TR VALIGN=top><TD><B>Interface</B></TD><TD><B>Attribute</B></TD><TD><B>Value</B><BR></TD></TR>
<TR VALIGN=top><TD>
<B>pthread_attr_setschedparam</B>(),
<B>pthread_attr_getschedparam</B>()
</TD><TD>Thread safety</TD><TD>MT-Safe<BR></TD></TR>
</TABLE>
<A NAME="lbAH">&nbsp;</A>
<H2>CONFORMING TO</H2>
POSIX.1-2001, POSIX.1-2008.
<A NAME="lbAI">&nbsp;</A>
<H2>NOTES</H2>
See
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_setschedpolicy">pthread_attr_setschedpolicy</A></B>(3)
for a list of the thread scheduling policies supported on Linux.
<A NAME="lbAJ">&nbsp;</A>
<H2>EXAMPLE</H2>
See
<B><A HREF="/cgi-bin/man/man2html?3+pthread_setschedparam">pthread_setschedparam</A></B>(3).
<A NAME="lbAK">&nbsp;</A>
<H2>SEE ALSO</H2>
<B><A HREF="/cgi-bin/man/man2html?2+sched_get_priority_min">sched_get_priority_min</A></B>(2),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_init">pthread_attr_init</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_setinheritsched">pthread_attr_setinheritsched</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_attr_setschedpolicy">pthread_attr_setschedpolicy</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_create">pthread_create</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_setschedparam">pthread_setschedparam</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+pthread_setschedprio">pthread_setschedprio</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?7+pthreads">pthreads</A></B>(7),
<B><A HREF="/cgi-bin/man/man2html?7+sched">sched</A></B>(7)
<A NAME="lbAL">&nbsp;</A>
<H2>COLOPHON</H2>
This page is part of release 5.05 of the Linux
<I>man-pages</I>
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
<A HREF="https://www.kernel.org/doc/man-pages/.">https://www.kernel.org/doc/man-pages/.</A>
<P>
<HR>
<A NAME="index">&nbsp;</A><H2>Index</H2>
<DL>
<DT id="2"><A HREF="#lbAB">NAME</A><DD>
<DT id="3"><A HREF="#lbAC">SYNOPSIS</A><DD>
<DT id="4"><A HREF="#lbAD">DESCRIPTION</A><DD>
<DT id="5"><A HREF="#lbAE">RETURN VALUE</A><DD>
<DT id="6"><A HREF="#lbAF">ERRORS</A><DD>
<DT id="7"><A HREF="#lbAG">ATTRIBUTES</A><DD>
<DT id="8"><A HREF="#lbAH">CONFORMING TO</A><DD>
<DT id="9"><A HREF="#lbAI">NOTES</A><DD>
<DT id="10"><A HREF="#lbAJ">EXAMPLE</A><DD>
<DT id="11"><A HREF="#lbAK">SEE ALSO</A><DD>
<DT id="12"><A HREF="#lbAL">COLOPHON</A><DD>
</DL>
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