1<h2>thread_sample</h2> 2<hr> 3<p> 4<strong>Function</strong> - Perform periodic PC sampling for a thread. 5<h3>SYNOPSIS</h3> 6<pre> 7<strong>kern_return_t thread_sample</strong> 8 <strong>(thread_act_t</strong> <var>sample_thread</var>, 9 <strong>mach_port_make_send_t</strong> <var>reply_port</var><strong>);</strong> 10</pre> 11<h3>PARAMETERS</h3> 12<dl> 13<p> 14<dt> <var>sample_thread</var> 15<dd> 16[in thread send right] 17Thread whose PC is to be sampled 18<p> 19<dt> <var>reply_port</var> 20<dd> 21[in sample receive (to be converted to send) right] 22Port to which PC 23sample buffers are sent. A value of <strong>MACH_PORT_NULL</strong> stops PC 24sampling for the thread. 25</dl> 26<h3>DESCRIPTION</h3> 27<p> 28The <strong>thread_sample</strong> function causes the program counter 29(PC) of the specified 30<var>sample_thread</var> to be sampled periodically (whenever the thread happens to be 31running at the time of the kernel's "hardclock" interrupt). 32The set of PC sample 33values obtained are saved in buffers which are sent to the specified 34<var>reply_port</var> in 35<strong>receive_samples</strong> messages. 36<h3>RETURN VALUES</h3> 37<p> 38Only generic errors apply. 39<h3>RELATED INFORMATION</h3> 40<p> 41Functions: 42<a href="task_sample.html"><strong>task_sample</strong></a>, 43<a href="receive_samples.html"><strong>receive_samples</strong></a>. 44