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| <!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=UTF-8" /><title>Developer Information</title><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><meta name="keywords" content="C++, library, profile" /><meta name="keywords" content="ISO C++, library" /><meta name="keywords" content="ISO C++, runtime, library" /><link rel="home" href="../index.html" title="The GNU C++ Library" /><link rel="up" href="profile_mode.html" title="Chapter 19. Profile Mode" /><link rel="prev" href="profile_mode_impl.html" title="Implementation Issues" /><link rel="next" href="profile_mode_diagnostics.html" title="Diagnostics" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Developer Information</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="profile_mode_impl.html">Prev</a> </td><th width="60%" align="center">Chapter 19. Profile Mode</th><td width="20%" align="right"> <a accesskey="n" href="profile_mode_diagnostics.html">Next</a></td></tr></table><hr /></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="manual.ext.profile_mode.developer"></a>Developer Information</h2></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="manual.ext.profile_mode.developer.bigpic"></a>Big Picture</h3></div></div></div><p>The profile mode headers are included with |
| <code class="code">-D_GLIBCXX_PROFILE</code> through preprocessor directives in |
| <code class="code">include/std/*</code>. |
| </p><p>Instrumented implementations are provided in |
| <code class="code">include/profile/*</code>. All instrumentation hooks are macros |
| defined in <code class="code">include/profile/profiler.h</code>. |
| </p><p>All the implementation of the instrumentation hooks is in |
| <code class="code">include/profile/impl/*</code>. Although all the code gets included, |
| thus is publicly visible, only a small number of functions are called from |
| outside this directory. All calls to hook implementations must be |
| done through macros defined in <code class="code">profiler.h</code>. The macro |
| must ensure (1) that the call is guarded against reentrance and |
| (2) that the call can be turned off at compile time using a |
| <code class="code">-D_GLIBCXX_PROFILE_...</code> compiler option. |
| </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="manual.ext.profile_mode.developer.howto"></a>How To Add A Diagnostic</h3></div></div></div><p>Let's say the diagnostic name is "magic". |
| </p><p>If you need to instrument a header not already under |
| <code class="code">include/profile/*</code>, first edit the corresponding header |
| under <code class="code">include/std/</code> and add a preprocessor directive such |
| as the one in <code class="code">include/std/vector</code>: |
| </p><pre class="programlisting"> |
| #ifdef _GLIBCXX_PROFILE |
| # include <profile/vector> |
| #endif |
| </pre><p> |
| </p><p>If the file you need to instrument is not yet under |
| <code class="code">include/profile/</code>, make a copy of the one in |
| <code class="code">include/debug</code>, or the main implementation. |
| You'll need to include the main implementation and inherit the classes |
| you want to instrument. Then define the methods you want to instrument, |
| define the instrumentation hooks and add calls to them. |
| Look at <code class="code">include/profile/vector</code> for an example. |
| </p><p>Add macros for the instrumentation hooks in |
| <code class="code">include/profile/impl/profiler.h</code>. |
| Hook names must start with <code class="code">__profcxx_</code>. |
| Make sure they transform |
| in no code with <code class="code">-D_NO_GLIBCXX_PROFILE_MAGIC</code>. |
| Make sure all calls to any method in namespace <code class="code">__gnu_profile</code> |
| is protected against reentrance using macro |
| <code class="code">_GLIBCXX_PROFILE_REENTRANCE_GUARD</code>. |
| All names of methods in namespace <code class="code">__gnu_profile</code> called from |
| <code class="code">profiler.h</code> must start with <code class="code">__trace_magic_</code>. |
| </p><p>Add the implementation of the diagnostic. |
| </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> |
| Create new file <code class="code">include/profile/impl/profiler_magic.h</code>. |
| </p></li><li class="listitem"><p> |
| Define class <code class="code">__magic_info: public __object_info_base</code>. |
| This is the representation of a line in the object table. |
| The <code class="code">__merge</code> method is used to aggregate information |
| across all dynamic instances created at the same call context. |
| The <code class="code">__magnitude</code> must return the estimation of the benefit |
| as a number of small operations, e.g., number of words copied. |
| The <code class="code">__write</code> method is used to produce the raw trace. |
| The <code class="code">__advice</code> method is used to produce the advice string. |
| </p></li><li class="listitem"><p> |
| Define class <code class="code">__magic_stack_info: public __magic_info</code>. |
| This defines the content of a line in the stack table. |
| </p></li><li class="listitem"><p> |
| Define class <code class="code">__trace_magic: public __trace_base<__magic_info, |
| __magic_stack_info></code>. |
| It defines the content of the trace associated with this diagnostic. |
| </p></li></ul></div><p> |
| </p><p>Add initialization and reporting calls in |
| <code class="code">include/profile/impl/profiler_trace.h</code>. Use |
| <code class="code">__trace_vector_to_list</code> as an example. |
| </p><p>Add documentation in file <code class="code">doc/xml/manual/profile_mode.xml</code>. |
| </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="profile_mode_impl.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="profile_mode.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="profile_mode_diagnostics.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Implementation Issues </td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> Diagnostics</td></tr></table></div></body></html> |
