📄 pthread_attr_getschedpolicy.html
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta name="generator" content="HTML Tidy, see www.w3.org"><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><link type="text/css" rel="stylesheet" href="style.css"><!-- Generated by The Open Group's rhtm tool v1.2.1 --><!-- Copyright (c) 2001-2004 IEEE and The Open Group, All Rights Reserved --><title>pthread_attr_getschedpolicy</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="pthread_attr_getschedpolicy"></a> <a name="tag_03_492"></a><!-- pthread_attr_getschedpolicy --> <!--header start--><center><font size="2">The Open Group Base Specifications Issue 6<br>IEEE Std 1003.1, 2004 Edition<br>Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.</font></center><!--header end--><hr size="2" noshade><h4><a name="tag_03_492_01"></a>NAME</h4><blockquote>pthread_attr_getschedpolicy, pthread_attr_setschedpolicy - get and set the schedpolicy attribute (<b>REALTIMETHREADS</b>)</blockquote><h4><a name="tag_03_492_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><div class="box"><code><tt><sup>[<a href="javascript:open_code('THR TPS')">THR TPS</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> #include <<a href="../basedefs/pthread.h.html">pthread.h</a>><br><br> int pthread_attr_getschedpolicy(const pthread_attr_t *restrict</tt> <i>attr</i><tt>,<br> int *restrict</tt> <i>policy</i><tt>);<br> int pthread_attr_setschedpolicy(pthread_attr_t *</tt><i>attr</i><tt>, int</tt> <i>policy</i><tt>); <img src="../images/opt-end.gif" alt="[Option End]" border="0"></tt></code></div><tt><br></tt></blockquote><h4><a name="tag_03_492_03"></a>DESCRIPTION</h4><blockquote><p>The <i>pthread_attr_getschedpolicy</i>() and <i>pthread_attr_setschedpolicy</i>() functions, respectively, shall get and set the<i>schedpolicy</i> attribute in the <i>attr</i> argument.</p><p>The supported values of <i>policy</i> shall include SCHED_FIFO, SCHED_RR, and SCHED_OTHER, which are defined in the <a href="../basedefs/sched.h.html"><i><sched.h></i></a> header. When threads executing with the scheduling policy SCHED_FIFO,SCHED_RR, <sup>[<a href="javascript:open_code('TSP')">TSP</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]"border="0"> or SCHED_SPORADIC <img src="../images/opt-end.gif" alt="[Option End]" border="0"> are waiting on a mutex, theyshall acquire the mutex in priority order when the mutex is unlocked.</p></blockquote><h4><a name="tag_03_492_04"></a>RETURN VALUE</h4><blockquote><p>If successful, the <i>pthread_attr_getschedpolicy</i>() and <i>pthread_attr_setschedpolicy</i>() functions shall return zero;otherwise, an error number shall be returned to indicate the error.</p></blockquote><h4><a name="tag_03_492_05"></a>ERRORS</h4><blockquote><p>The <i>pthread_attr_getschedpolicy</i>() function may fail if:</p><dl compact><dt>[EINVAL]</dt><dd>The value specified by <i>attr</i> does not refer to an initialized thread attribute object.</dd></dl><p>The <i>pthread_attr_setschedpolicy</i>() function may fail if:</p><dl compact><dt>[EINVAL]</dt><dd>The value of <i>policy</i> is not valid, or the value specified by <i>attr</i> does not refer to an initialized threadattribute object.</dd><dt>[ENOTSUP]</dt><dd>An attempt was made to set the attribute to an unsupported value.</dd></dl><p>These functions shall not return an error code of [EINTR].</p></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_03_492_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_492_07"></a>APPLICATION USAGE</h4><blockquote><p>After these attributes have been set, a thread can be created with the specified attributes using <a href="../functions/pthread_create.html"><i>pthread_create</i>()</a>. Using these routines does not affect the current runningthread.</p><p>See <a href="xsh_chap02_09.html#tag_02_09_04"><i>Thread Scheduling</i></a> for further details on thread scheduling attributesand their default settings.</p></blockquote><h4><a name="tag_03_492_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_492_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_492_10"></a>SEE ALSO</h4><blockquote><p><a href="pthread_attr_destroy.html"><i>pthread_attr_destroy</i>()</a>, <a href="pthread_attr_getscope.html"><i>pthread_attr_getscope</i>()</a>, <a href="pthread_attr_getinheritsched.html"><i>pthread_attr_getinheritsched</i>()</a>, <a href="pthread_attr_getschedparam.html"><i>pthread_attr_getschedparam</i>()</a>, <a href="pthread_create.html"><i>pthread_create</i>()</a>, the Base Definitions volume of IEEE Std 1003.1-2001, <a href="../basedefs/pthread.h.html"><i><pthread.h></i></a>, <a href="../basedefs/sched.h.html"><i><sched.h></i></a></p></blockquote><h4><a name="tag_03_492_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 5. Included for alignment with the POSIX Threads Extension.</p><p>Marked as part of the Realtime Threads Feature Group.</p></blockquote><h4><a name="tag_03_492_12"></a>Issue 6</h4><blockquote><p>The <i>pthread_attr_getschedpolicy</i>() and <i>pthread_attr_setschedpolicy</i>() functions are marked as part of the Threadsand Thread Execution Scheduling options.</p><p>The [ENOSYS] error condition has been removed as stubs need not be provided if an implementation does not support the ThreadExecution Scheduling option.</p><p>The SCHED_SPORADIC scheduling policy is added for alignment with IEEE Std 1003.1d-1999.</p><p>The <b>restrict</b> keyword is added to the <i>pthread_attr_getschedpolicy</i>() prototype for alignment with theISO/IEC 9899:1999 standard.</p><p>IEEE Std 1003.1-2001/Cor 2-2004, item XSH/TC2/D6/79 is applied, adding a reference to <a href="xsh_chap02_09.html#tag_02_09_04"><i>Thread Scheduling</i></a> in the APPLICATION USAGE section.</p><p>IEEE Std 1003.1-2001/Cor 2-2004, item XSH/TC2/D6/80 is applied, updating the ERRORS section to include optionalerrors for the case when <i>attr</i> refers to an uninitialized thread attribute object.</p></blockquote><div class="box"><em>End of informative text.</em></div><hr size="2" noshade><center><font size="2"><!--footer start-->UNIX ® is a registered Trademark of The Open Group.<br>POSIX ® is a registered Trademark of The IEEE.<br>[ <a href="../mindex.html">Main Index</a> | <a href="../basedefs/contents.html">XBD</a> | <a href="../utilities/contents.html">XCU</a> | <a href="../functions/contents.html">XSH</a> | <a href="../xrat/contents.html">XRAT</a>]</font></center><!--footer end--><hr size="2" noshade></body></html>⌨️ 快捷键说明
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