<?xml version="1.0" encoding="ANSI_X3.4-1968" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>futex_top_waiter</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1" /><link rel="home" href="index.html" title="Unreliable Guide To Locking" /><link rel="up" href="apiref-futex.html" title="Chapter 12. Futex API reference" /><link rel="prev" href="API-fault-in-user-writeable.html" title="fault_in_user_writeable" /><link rel="next" href="API-futex-lock-pi-atomic.html" title="futex_lock_pi_atomic" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="phrase">futex_top_waiter</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-fault-in-user-writeable.html">Prev</a> </td><th width="60%" align="center">Chapter 12. Futex API reference</th><td width="20%" align="right"> <a accesskey="n" href="API-futex-lock-pi-atomic.html">Next</a></td></tr></table><hr /></div><div class="refentry"><a id="API-futex-top-waiter"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>futex_top_waiter — Return the highest priority waiter on a futex </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">struct futex_q * <strong class="fsfunc">futex_top_waiter </strong>(</code></td><td>struct futex_hash_bucket * <var class="pdparam">hb</var>, </td></tr><tr><td> </td><td>union futex_key * <var class="pdparam">key</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="idm140391696152608"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>hb</code></em></span></dt><dd><p> the hash bucket the futex_q's reside in </p></dd><dt><span class="term"><em class="parameter"><code>key</code></em></span></dt><dd><p> the futex key (to distinguish it from other futex futex_q's) </p></dd></dl></div></div><div class="refsect1"><a id="idm140391696147568"></a><h2>Description</h2><p> Must be called with the hb lock held. </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-fault-in-user-writeable.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="apiref-futex.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="API-futex-lock-pi-atomic.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">fault_in_user_writeable</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span class="phrase">futex_lock_pi_atomic</span></td></tr></table></div></body></html>