1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>fence_is_signaled</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="ch02s03.html" title="Device Drivers DMA Management"><link rel="prev" href="API-fence-is-signaled-locked.html" title="fence_is_signaled_locked"><link rel="next" href="API-fence-later.html" title="fence_later"></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">fence_is_signaled</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-fence-is-signaled-locked.html">Prev</a>&#160;</td><th width="60%" align="center">Device Drivers DMA Management</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-fence-later.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-fence-is-signaled"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>fence_is_signaled &#8212; 
2     Return an indication if the fence is signaled yet.
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">bool <b class="fsfunc">fence_is_signaled </b>(</code></td><td>struct fence * <var class="pdparam">fence</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1110451596"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>fence</code></em></span></dt><dd><p>
4     [in]	the fence to check
5    </p></dd></dl></div></div><div class="refsect1"><a name="idp1110453212"></a><h2>Description</h2><p>
6   Returns true if the fence was already signaled, false if not. Since this
7   function doesn't enable signaling, it is not guaranteed to ever return
8   true if fence_add_callback, fence_wait or fence_enable_sw_signaling
9   haven't been called before.
10   </p><p>
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12   It's recommended for seqno fences to call fence_signal when the
13   operation is complete, it makes it possible to prevent issues from
14   wraparound between time of issue and time of use by checking the return
15   value of this function before calling hardware-specific wait instructions.
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