xref: /xnu-10002.1.13/osfmk/man/thread_sample.html (revision 1031c584a5e37aff177559b9f69dbd3c8c3fd30a)
1*1031c584SApple OSS Distributions<h2>thread_sample</h2>
2*1031c584SApple OSS Distributions<hr>
3*1031c584SApple OSS Distributions<p>
4*1031c584SApple OSS Distributions<strong>Function</strong> - Perform periodic PC sampling for a thread.
5*1031c584SApple OSS Distributions<h3>SYNOPSIS</h3>
6*1031c584SApple OSS Distributions<pre>
7*1031c584SApple OSS Distributions<strong>kern_return_t   thread_sample</strong>
8*1031c584SApple OSS Distributions                <strong>(thread_act_t</strong>                     <var>sample_thread</var>,
9*1031c584SApple OSS Distributions                 <strong>mach_port_make_send_t</strong>               <var>reply_port</var><strong>);</strong>
10*1031c584SApple OSS Distributions</pre>
11*1031c584SApple OSS Distributions<h3>PARAMETERS</h3>
12*1031c584SApple OSS Distributions<dl>
13*1031c584SApple OSS Distributions<p>
14*1031c584SApple OSS Distributions<dt> <var>sample_thread</var>
15*1031c584SApple OSS Distributions<dd>
16*1031c584SApple OSS Distributions[in thread send right]
17*1031c584SApple OSS DistributionsThread whose PC is to be sampled
18*1031c584SApple OSS Distributions<p>
19*1031c584SApple OSS Distributions<dt> <var>reply_port</var>
20*1031c584SApple OSS Distributions<dd>
21*1031c584SApple OSS Distributions[in sample receive (to be converted to send) right]
22*1031c584SApple OSS DistributionsPort to which PC
23*1031c584SApple OSS Distributionssample buffers are sent.  A value of <strong>MACH_PORT_NULL</strong> stops PC
24*1031c584SApple OSS Distributionssampling for the thread.
25*1031c584SApple OSS Distributions</dl>
26*1031c584SApple OSS Distributions<h3>DESCRIPTION</h3>
27*1031c584SApple OSS Distributions<p>
28*1031c584SApple OSS DistributionsThe <strong>thread_sample</strong> function causes the program counter
29*1031c584SApple OSS Distributions(PC) of the specified
30*1031c584SApple OSS Distributions<var>sample_thread</var> to be sampled periodically (whenever the thread happens to be
31*1031c584SApple OSS Distributionsrunning at the time of the kernel's "hardclock" interrupt).
32*1031c584SApple OSS DistributionsThe set of PC sample
33*1031c584SApple OSS Distributionsvalues obtained are saved in buffers which are sent to the specified
34*1031c584SApple OSS Distributions<var>reply_port</var> in
35*1031c584SApple OSS Distributions<strong>receive_samples</strong> messages.
36*1031c584SApple OSS Distributions<h3>RETURN VALUES</h3>
37*1031c584SApple OSS Distributions<p>
38*1031c584SApple OSS DistributionsOnly generic errors apply.
39*1031c584SApple OSS Distributions<h3>RELATED INFORMATION</h3>
40*1031c584SApple OSS Distributions<p>
41*1031c584SApple OSS DistributionsFunctions:
42*1031c584SApple OSS Distributions<a href="task_sample.html"><strong>task_sample</strong></a>,
43*1031c584SApple OSS Distributions<a href="receive_samples.html"><strong>receive_samples</strong></a>.
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