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<concept id="GUID-8105D1FC-DFFE-59F0-A664-3DA44F002F47" xml:lang="en"><title>Enabling
File Server Tracing</title><shortdesc>This document describes how to enable trace points in the file
server client API (EFSRV.DLL), the file system API (*.FSY) , and/or the proxy
drive API. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
<section id="GUID-E4208794-E751-4626-A457-FB81B330AC9E"><title>Introduction</title> <p>Enabling a trace point
results in trace data being output to the trace buffer. </p> <p>Tracing can
be enabled or disabled (i.e. compiled in or out) at build time. By default
file server tracing is enabled in debug builds of EFSRV.DLL and EFILE.EXE
and disabled in release builds. To enable tracing in release builds, there
are two options: </p> <ul>
<li id="GUID-CE4CBA1C-D699-568D-B97D-98CD01E7ADAC"><p>replace the release
builds of <filepath>EFSRV.DLL</filepath> /<filepath>EFILE.EXE</filepath> with
their debug equivalents. </p> </li>
<li id="GUID-76F59D55-BE9A-54E2-9A77-068F292334B0"><p>rebuild <filepath>EFSRV.DLL</filepath> /<filepath>EFILE.EXE</filepath> using <filepath>efsrv_instrumented.mmp</filepath> /<filepath>efile_instrumented.mmp</filepath>. </p> </li>
</ul> <p>Tracing can also be enabled or disabled at run time or at device
startup. For more details, see <xref href="GUID-D5984540-A411-52ED-B435-94C67F34ADD5.dita">How
to enable tracing</xref>. </p> <p>The level of tracing required may be configured
by selecting one or more of the primary filters and one or more of the secondary
filters from the list below: </p> <codeblock id="GUID-DDA48DE7-651D-54D4-A3EA-81C053D5F4BC" xml:space="preserve">//Primary filters
EPanic = 192            // to trace panics
EError = 193            // to trace errors
EBorder = 195,            // to trace API calls</codeblock> <codeblock id="GUID-3253FF5A-ABAC-5A2D-9CE9-D420B855FB88" xml:space="preserve">//Secondary filters
EF32TraceUidEfsrv         =     0x100039e4 //    (268450276 in decimal)
EF32TraceUidFileSys        =    0x10286575 //    (271082869 in decimal)
EF32TraceUidProxyDrive    =    0x10286576 //    (271082870 in decimal)</codeblock><p> For
more details on capturing the trace data see <xref href="GUID-71884BEF-0A49-5F56-BE26-EFFD77FA846A.dita">how
to output traces</xref>.  </p> </section>
<section id="GUID-AF241F65-5BCA-4BDA-9852-EF6033574A5E"><title>APIs </title> <p>The following table lists the classes to
which the trace points have been added. It has been divided into three broad
categories as shown below. </p> <ul>
<li id="GUID-930F772C-DC22-5D44-92D5-1EED6CDC02A9"><p> <b>File system</b>  </p> <ul>
<li id="GUID-938ED57F-0365-56BA-BD78-854CAE8BC344"><p> <xref href="GUID-0012B043-9FC4-3953-928E-CB6107E0486A.dita"><apiname>CFileSystem</apiname></xref>  </p> </li>
<li id="GUID-5A54ADD0-2F79-54A2-8725-EE738F51FC5F"><p> <xref href="GUID-FADDE053-CC1C-39BC-A52D-27093041BE20.dita"><apiname>CMountCB</apiname></xref>  </p> </li>
<li id="GUID-87CD0966-EE3B-5517-B69D-024B308EB4B1"><p> <xref href="GUID-63DF657C-434D-353D-A536-8AF9D97C8260.dita"><apiname>CFileCB</apiname></xref>  </p> </li>
<li id="GUID-08DCCC4C-2A4B-560C-96C2-55C949086F4B"><p> <xref href="GUID-B19ADEA9-5018-3773-92BC-C16306D15043.dita"><apiname>CDirCB</apiname></xref>  </p> </li>
<li id="GUID-901B069A-A234-5238-94C0-B88723DA0698"><p> <xref href="GUID-E0C22CEA-845F-37A2-85DE-0ACD7927FA41.dita"><apiname>CFormatCB</apiname></xref>  </p> </li>
</ul> </li>
<li id="GUID-54DAF9C2-385A-5C5D-B808-DD42BD96D2B2"><p> <b>Proxy drive</b>  </p> <ul>
<li id="GUID-D082BF1C-A7F1-597D-BE7E-19FDAFE25368"><p> <xref href="GUID-F47F56E4-3754-365B-B529-53C1D2A29503.dita"><apiname>CLocalProxyDrive</apiname></xref>  </p> </li>
<li id="GUID-7115117E-68B1-5CCB-BEAE-668CF45DE9AD"><p> <xref href="GUID-FAFF712B-2295-3907-B839-D77F052160DA.dita"><apiname>CBaseExtProxyDrive</apiname></xref>  </p> </li>
</ul> </li>
<li id="GUID-ABC75EC4-EBBE-5F85-AA09-A1E77B121FBC"><p> <b>File server</b>  </p> <ul>
<li id="GUID-54E6118B-454D-50B6-8BA1-6C5A74E6A70C"><p> <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita"><apiname>RFile</apiname></xref>  </p> </li>
<li id="GUID-E9839BE3-3F7B-54BE-A52A-ECEBC4CE7691"><p> <xref href="GUID-E263C747-946F-35AA-9F1D-41833BD350FC.dita"><apiname>RFs</apiname></xref>  </p> </li>
<li id="GUID-5D365808-C2C1-5CC3-9E69-1423C47CBCE5"><p> <xref href="GUID-12AE154F-7741-38C0-ADFE-9784FCF5E516.dita"><apiname>RDir</apiname></xref>  </p> </li>
<li id="GUID-D4F74F2A-F919-5AB9-89EA-1C45420E4391"><p> <xref href="GUID-9D7E765B-6872-3EB9-9D5B-1503FA466EC1.dita"><apiname>RFormat</apiname></xref>  </p> </li>
<li id="GUID-39021B3E-2F79-51A7-8158-4D08B94CCF4D"><p> <xref href="GUID-118CCC9E-C58B-3AA0-86A8-219914E7E7BC.dita"><apiname>RPlugin</apiname></xref>  </p> </li>
<li id="GUID-264C14C5-69D3-5662-9BFD-15B7FCB22F00"><p> <xref href="GUID-82CEC14F-1479-3922-846A-9FCDB6465EF7.dita"><apiname>CFileMan</apiname></xref>  </p> </li>
<li id="GUID-817F4158-5F9F-5D21-9FA1-42D5EC6F774F"><p> <xref href="GUID-C657AF2D-1183-3CD2-ACAF-3B0B00FC91BB.dita"><apiname>CDirScan</apiname></xref>  </p> </li>
</ul> </li>
</ul> <p>Trace points have been added to the public exported functions of
the classes listed above. As an example, the code fragment below illustrates
how the tracepoints have been added and what type of information is output
for the Open function of the <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita"><apiname>RFile</apiname></xref> class: </p> <codeblock id="GUID-44DCCB86-9835-5A03-A17C-A78F43A58FD6" xml:space="preserve">
EFSRV_EXPORT_C TInt RFile::Open(RFs&amp; aFs,const TDesC&amp; aName,TUint aMode)
{
TRACEMULT3(UTF::EBorder, UTraceModuleEfsrv::EFileOpen, MODULEUID, aFs.Handle(), aMode, aName);

aMode &amp;= ~EFileBigFile;
TInt r = CreateSubSession(aFs,EFsFileOpen,TIpcArgs(&amp;aName,aMode));

TRACERET2(UTF::EBorder, UTraceModuleEfsrv::EFileOpenReturn, MODULEUID, r, SubSessionHandle());

return r;
}</codeblock> <p>A sample trace output is as shown: </p> <codeblock id="GUID-A7782683-9A99-5B9B-AD52-81CC236CB7D1" xml:space="preserve">RFile::Open() sess 0x00008000 mode 0x00000100 FileName Z:\SYS\DATA\ESTARTFILESYSTEMS.TXT</codeblock> </section>
<section id="GUID-A46311CE-B4C4-4BE9-A698-5DC1C18D6C60"><title>Interpretation of the trace data</title> <p>Symbian does not
currently provide a tool for decoding file server trace data (though hopefully
this will change in the near future). The data can, however, be interpreted
by examining the following two publicly exported header files which provides
detail of what fields are output by each tracepoint. </p> <ul>
<li id="GUID-3032957A-5D64-57AD-98FD-DF82D6959C10"><p> <filepath>\epoc32\include\utraceefsrv.h </filepath>  </p> </li>
<li id="GUID-8C8C91AD-757A-5A79-861B-2686178FB154"><p> <filepath>\epoc32\include\utraceefile.h</filepath>  </p> </li>
</ul> <p>For example: </p> <codeblock id="GUID-2B0DD8BA-5AC5-5369-8410-4A21B987D926" xml:space="preserve">
/** @SYMTraceFormatString "RFile::Replace() sess %x mode %x FileName %*S" */
EFileReplace</codeblock> <p>In the above example the trace record will contain
the session <xref href="GUID-E263C747-946F-35AA-9F1D-41833BD350FC.dita"><apiname>RFs</apiname></xref> handle, the file open mode and the filename. </p> </section>
</conbody><related-links>
<link href="GUID-A3E77067-7982-5803-A274-0C8F2562B483.dita"><linktext>Unified Trace
solution</linktext></link>
<link href="GUID-7B477BA5-CC5B-56A2-82BC-E1BC0049FECB.dita"><linktext>Kernel Trace
Tool Overview</linktext></link>
</related-links></concept>