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  11 <h1>dmxsync.c File Reference</h1><code>#include "<a class="el" href="dmx_8h-source.html">dmx.h</a>"</code><br>
  12 <code>#include "<a class="el" href="dmxsync_8h-source.html">dmxsync.h</a>"</code><br>
  13 <code>#include "<a class="el" href="dmxstat_8h-source.html">dmxstat.h</a>"</code><br>
  14 <code>#include "<a class="el" href="dmxlog_8h-source.html">dmxlog.h</a>"</code><br>
  15 <code>#include &lt;sys/time.h&gt;</code><br>
  16 <table border=0 cellpadding=0 cellspacing=0>
  17 <tr><td></td></tr>
  18 <tr><td colspan=2><br><h2>Functions</h2></td></tr>
  19 <tr><td class="memItemLeft" nowrap align=right valign=top>void&nbsp;</td><td class="memItemRight" valign=bottom><a class="el" href="dmxsync_8c.html#a7">dmxSyncActivate</a> (const  char *interval)</td></tr>
  20
  21 <tr><td class="memItemLeft" nowrap align=right valign=top>void&nbsp;</td><td class="memItemRight" valign=bottom><a class="el" href="dmxsync_8c.html#a8">dmxSyncInit</a> (void)</td></tr>
  22
  23 <tr><td class="memItemLeft" nowrap align=right valign=top>void&nbsp;</td><td class="memItemRight" valign=bottom><a class="el" href="dmxsync_8c.html#a9">dmxSync</a> (<a class="el" href="struct__DMXScreenInfo.html">DMXScreenInfo</a> *dmxScreen, Bool now)</td></tr>
  24
  25 </table>
  26 <hr><a name="_details"></a><h2>Detailed Description</h2>
  27 The DMX server code is written to call <a class="el" href="dmxsync_8c.html#a9">dmxSync()</a> whenever an XSync() might be necessary. However, since XSync() requires a two way communication with the other X server, eliminating unnecessary XSync() calls is a key performance optimization. Support for this optimization is provided here. Statistics about XSync() calls and latency are gathered in #dmxstat.c.<p>
  28 During the initial conversion from calling XSync() immediately to the XSync() batching method implemented in this file, it was noted that, out of more than 300 <em>x11perf</em> tests, 8 tests became more than 100 times faster, with 68 more than 50X faster, 114 more than 10X faster, and 181 more than 2X faster.<hr><h2>Function Documentation</h2>
  29 <a class="anchor" name="a9" doxytag="dmxsync.c::dmxSync" ></a><p>
  30 <table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
  31   <tr>
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  35           <td class="md" nowrap valign="top"> void dmxSync </td>
  36           <td class="md" valign="top">(&nbsp;</td>
  37           <td class="md" nowrap valign="top"><a class="el" href="struct__DMXScreenInfo.html">DMXScreenInfo</a> *&nbsp;</td>
  38           <td class="mdname" nowrap> <em>dmxScreen</em>, </td>
  39         </tr>
  40         <tr>
  41           <td></td>
  42           <td></td>
  43           <td class="md" nowrap>Bool&nbsp;</td>
  44           <td class="mdname" nowrap> <em>now</em></td>
  45         </tr>
  46         <tr>
  47           <td></td>
  48           <td class="md">)&nbsp;</td>
  49           <td class="md" colspan="2"></td>
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  62
  63 <p>
  64 Request an XSync() to the display used by <em>dmxScreen</em>. If <em>now</em> is TRUE, call XSync() immediately instead of waiting for the next XSync() batching point. Note that if XSync() batching was deselected with <a class="el" href="dmxsync_8c.html#a7">dmxSyncActivate()</a> before <a class="el" href="dmxsync_8c.html#a8">dmxSyncInit()</a> was called, then no XSync() batching is performed and this function always calles XSync() immediately.<p>
  65 (Note that this function uses TimerSet but works correctly in the face of a server generation. See the source for details.)<p>
  66 If <em>dmxScreen</em> is <em>NULL</em>, then all pending syncs will be flushed immediately.     </td>
  67   </tr>
  68 </table>
  69 <a class="anchor" name="a7" doxytag="dmxsync.c::dmxSyncActivate" ></a><p>
  70 <table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
  71   <tr>
  72     <td class="mdRow">
  73       <table cellpadding="0" cellspacing="0" border="0">
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  75           <td class="md" nowrap valign="top"> void dmxSyncActivate </td>
  76           <td class="md" valign="top">(&nbsp;</td>
  77           <td class="md" nowrap valign="top">const char *&nbsp;</td>
  78           <td class="mdname1" valign="top" nowrap> <em>interval</em>          </td>
  79           <td class="md" valign="top">&nbsp;)&nbsp;</td>
  80           <td class="md" nowrap></td>
  81         </tr>
  82
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  94 <p>
  95 Request the XSync() batching optimization with the specified <em>interval</em> (in mS). If the <em>interval</em> is 0, 100mS is used. If the <em>interval</em> is less than 0, then the XSync() batching optimization is not requested (e.g., so the -syncbatch -1 command line option can turn off the default 100mS XSync() batching).<p>
  96 Note that the parameter to this routine is a string, since it will usually be called from <a class="el" href="dmxinit_8c.html#a40">ddxProcessArgument</a> in #dmxinit.c     </td>
  97   </tr>
  98 </table>
  99 <a class="anchor" name="a8" doxytag="dmxsync.c::dmxSyncInit" ></a><p>
 100 <table class="mdTable" width="100%" cellpadding="2" cellspacing="0">
 101   <tr>
 102     <td class="mdRow">
 103       <table cellpadding="0" cellspacing="0" border="0">
 104         <tr>
 105           <td class="md" nowrap valign="top"> void dmxSyncInit </td>
 106           <td class="md" valign="top">(&nbsp;</td>
 107           <td class="md" nowrap valign="top">void&nbsp;</td>
 108           <td class="mdname1" valign="top" nowrap>          </td>
 109           <td class="md" valign="top">&nbsp;)&nbsp;</td>
 110           <td class="md" nowrap></td>
 111         </tr>
 112
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 123
 124 <p>
 125 Initialize the XSync() batching optimization, but only if <a class="el" href="dmxsync_8h.html#a0">dmxSyncActivate</a> was last called with a non-negative value.     </td>
 126   </tr>
 127 </table>
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