trace/traceviewer/com.nokia.traceviewer.help/html/concepts/when_to_use_ost.htm
author Matti Laitinen <matti.t.laitinen@nokia.com>
Wed, 23 Jun 2010 14:49:59 +0300
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<html>
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<head>
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<meta http-equiv="content-type" content="text/html; charset=iso-8859-1">
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<title>When to use OST traces</title>
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<link href="../../book.css" type="text/css" rel="stylesheet"></head>
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<body>
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<h2>When to use OST traces</h2>
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<p>In general, it is not good idea to trace &ldquo;just in case&rdquo;, 
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or to see that everything works OK. Consider these points: </p>
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<ul>
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<li>Use traces to find the rough location of the problem and then use a debugger
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for the rest of the job. You save time as you are able to see registers, call-stacks
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and program variables. Do not debug using traces, it is very slow.  </li>
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<li>Some good cases to use tracing are:  
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	<ul>
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		<li>in code that manages error situations,  </li>
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		<li>initialization or stopping of operation,  </li>
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		<li>control operations that happen rarely (user input, for example). </li>
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	</ul>
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</li>
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<li>It is not recommended to add traces to code that is called very often,
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as each software tracepoint causes performance overhead. When tracepoint is
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not activated, some time is spent for checking if the trace is activated or
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not. When tracepoint is activated, additional time is taken when sending it
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to the trace port.</li>
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<li>If you get error reports after your code has been submitted to the release,
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well-planned traces can help you find out what went wrong and where to start
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looking for the problem. You can even instruct the problem reporter to take
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additional trace log with certain tracepoints enabled: <i>&ldquo;Send us a
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log where tracegroups X and Y from component Z are activated.&rdquo; </i></li>
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</ul>
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<h5>Related concepts</h5>
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<ul>
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	<li><a href="trace_format.htm">Trace formats</a></li>
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</ul>
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<h5>Related tasks</h5>
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<ul>
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	<li><a href="../tasks/connect.htm">Connecting to the trace source</a></li>
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	<li><a href="../tasks/decoding_traces.htm">Decoding binary traces with a Dictionary file</a></li>
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	<li><a href="../tasks/traceactivation.htm">Activating traces</a></li>
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</ul>
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<div id="footer">Copyright &copy; 2007-2010 Nokia Corporation and/or its subsidiary(-ies). All rights reserved. 
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License: <a href="http://www.eclipse.org/legal/epl-v10.html">http://www.eclipse.org/legal/epl-v10.html</a>.</div>
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</body>
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</html>