<chapter id="tools">
  <title>GObject related tools</title>

  <sect1 id="tools-refdb">
    <title>Debugging reference count problems</title>
    
    <para>
      The reference counting scheme used by GObject does solve quite 
      a few memory management problems but also introduces new sources of bugs.
      In large applications, finding the exact spot where a the reference count
      of an Object is not properly handled can be very difficult. Hopefully, 
      there exist at a too named <ulink url="http://refdbg.sf.net/">refdbg/</ulink>
      which can be used to automate the task of tracking down the location
      of invalid code with regard to reference counting. This application 
      intercepts the reference counting calls and tries to detect invalid behavior. 
      It suports a filter-rule mechanism to let you trace only the objects you are 
      interested in and it can be used together with gdb.
    </para>
  </sect1>
  
  <sect1 id="tools-gtkdoc">
    <title>Writing API docs</title>

    <para>The API documentation for most of the Glib, GObject, GTK+ and GNOME
    libraries is built with a combination of complex tools. Typically, the part of 
    the documentation which describes the behavior of each function is extracted
    from the specially-formatted source code comments by a tool named gtk-doc which
    generates docbook xml and merges this docbook xml with a set of master xml 
    docbook files. These xml docbook files are finally processed with xsltproc
    (a small program part of the libxslt library) to generate the final html
    output. Other tools can be used to generate pdf output from the source xml.
    The following code excerpt shows what these comments look like.
<programlisting>
/**
 * gtk_widget_freeze_child_notify:
 * @widget: a #GtkWidget
 * 
 * Stops emission of "child-notify" signals on @widget. The signals are
 * queued until gtk_widget_thaw_child_notify() is called on @widget. 
 *
 * This is the analogue of g_object_freeze_notify() for child properties.
 **/
void
gtk_widget_freeze_child_notify (GtkWidget *widget)
{
...
</programlisting>
    </para>
    <para>
    The great thoroughful 
    <ulink url="http://developer.gnome.org/arch/doc/authors.html">documentation</ulink> 
    on how to setup and use gtk-doc in your
    project is provided on the gnome developer website.
    gtk-doc generates
    </para>
  </sect1>

</chapter>
