1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>threadgroup_lock</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Linux Device Drivers"><link rel="up" href="ch01s03.html" title="Delaying, scheduling, and timer routines"><link rel="prev" href="API-is-idle-task.html" title="is_idle_task"><link rel="next" href="API-threadgroup-unlock.html" title="threadgroup_unlock"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="phrase">threadgroup_lock</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-is-idle-task.html">Prev</a>&#160;</td><th width="60%" align="center">Delaying, scheduling, and timer routines</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-threadgroup-unlock.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-threadgroup-lock"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>threadgroup_lock &#8212; 
2     lock threadgroup
3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <b class="fsfunc">threadgroup_lock </b>(</code></td><td>struct task_struct * <var class="pdparam">tsk</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1106727292"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>tsk</code></em></span></dt><dd><p>
4     member task of the threadgroup to lock
5    </p></dd></dl></div></div><div class="refsect1"><a name="idp1106728876"></a><h2>Description</h2><p>
6   Lock the threadgroup <em class="parameter"><code>tsk</code></em> belongs to.  No new task is allowed to enter
7   and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
8   change -&gt;group_leader/pid.  This is useful for cases where the threadgroup
9   needs to stay stable across blockable operations.
10   </p><p>
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12   fork and exit paths explicitly call threadgroup_change_{begin|end}() for
13   synchronization.  While held, no new task will be added to threadgroup
14   and no existing live task will have its PF_EXITING set.
15   </p><p>
16
17   <code class="function">de_thread</code> does threadgroup_change_{begin|end}() when a non-leader
18   sub-thread becomes a new leader.
19</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-is-idle-task.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="ch01s03.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-threadgroup-unlock.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">is_idle_task</span>&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">threadgroup_unlock</span></td></tr></table></div></body></html>
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