etap_probe.html   [plain text]

<h2>etap_probe</h2>
<hr>
<p>
<strong>System Trap</strong> - Record event data in the kernel's
ETAP buffer(s).
<h3>SYNOPSIS</h3>
<pre>
<strong>#include&ltmach/etap.h&gt</strong>

<strong>kern_return_t   etap_probe</strong>
                <strong>(int</strong>                                   <var>event_id</var>,
                 <strong>event_id</strong>                             <var>data_size</var>,
                 <strong>etap_data_t</strong>                        <var>etap_data_t</var><strong>);</strong>
</pre>
<h3>PARAMETERS</h3>
<dl>
<p>
<dt> <var>event_id</var>
<dd>
A user defined value used to identify the event. 
<p>
<dt> <var>data_size</var>
<dd>
The size (in bytes) of the data being passed.
Note: The data size is limited to ETAP_DATA_SIZE,
(defined in <strong>mach/etap.h</strong>).
<p>
<dt> <var>data</var>
<dd>
A pointer to the event data being passed.
</dl>
<h3>DESCRIPTION</h3>
<p>
Application programmers may instrument their applications with
user-level probes, using the
<strong>etap_probe</strong> system call. All
event data passed to the kernel via
<strong>etap_probe</strong> is recorded in the
kernel's ETAP monitored buffer(s).  Each record includes a time stamp.
<h3>RETURN VALUES</h3>
<dl>
  <dt> <strong>KERN_SUCCESS</strong>
       <dd>
	    The call was performed successfully.
<p>
  <dt> <strong>KERN_INVALID_ARGUMENT</strong>
       <dd>
	    The specified data size exceeds ETAP_DATA_SIZE.
<p>
  <dt> <strong>KERN_NO_ACCESS</strong>
       <dd>
	    The tracing of user events is currently enabled.
<p>
  <dt> <strong>KERN_FAILURE</strong>
       <dd>
	    ETAP is not configured in the kernel.
</dl>
<h3>RELATED INFORMATION</h3>
<p>
Functions:
<a href="etap_trace_thread.html"><strong>etap_trace_thread</strong></a>,
<a href="etap_trace_event.html"><strong>etap_trace_event</strong></a>,
<a href="etap_get_info.html"><strong>etap_get_info</strong></a>.