xref: /xnu-8020.121.3/osfmk/man/task_sample.html (revision fdd8201d7b966f0c3ea610489d29bd841d358941)
1*fdd8201dSApple OSS Distributions<h2>task_sample</h2>
2*fdd8201dSApple OSS Distributions<hr>
3*fdd8201dSApple OSS Distributions<p>
4*fdd8201dSApple OSS Distributions<strong>Function</strong> - Sample the target task's thread program counters periodically.
5*fdd8201dSApple OSS Distributions<h3>SYNOPSIS</h3>
6*fdd8201dSApple OSS Distributions<pre>
7*fdd8201dSApple OSS Distributions<strong>kern_return_t   task_sample</strong>
8*fdd8201dSApple OSS Distributions                <strong>(task_t</strong>                             <var>sample_task</var>,
9*fdd8201dSApple OSS Distributions                 <strong>mach_port_make_send_t</strong>               <var>reply_port</var><strong>);</strong>
10*fdd8201dSApple OSS Distributions</pre>
11*fdd8201dSApple OSS Distributions<h3>PARAMETERS</h3>
12*fdd8201dSApple OSS Distributions<dl>
13*fdd8201dSApple OSS Distributions<p>
14*fdd8201dSApple OSS Distributions<dt> <var>sample_task</var>
15*fdd8201dSApple OSS Distributions<dd>
16*fdd8201dSApple OSS Distributions[in task send right]
17*fdd8201dSApple OSS DistributionsPort for the task whose threads' PC are to be
18*fdd8201dSApple OSS Distributionssampled.
19*fdd8201dSApple OSS Distributions<p>
20*fdd8201dSApple OSS Distributions<dt> <var>reply_port</var>
21*fdd8201dSApple OSS Distributions<dd>
22*fdd8201dSApple OSS Distributions[in sample receive (to be converted to send) right]
23*fdd8201dSApple OSS DistributionsPort to which PC sample buffers are sent.  A value of <strong>MACH_PORT_NULL</strong>
24*fdd8201dSApple OSS Distributionsstops PC sampling for the task.
25*fdd8201dSApple OSS Distributions</dl>
26*fdd8201dSApple OSS Distributions<h3>DESCRIPTION</h3>
27*fdd8201dSApple OSS Distributions<p>
28*fdd8201dSApple OSS DistributionsThe <strong>task_sample</strong> function causes the program counter (PC) of the
29*fdd8201dSApple OSS Distributionsspecified <var>sample_task</var> (actually, all of the threads within
30*fdd8201dSApple OSS Distributions<var>sample_task</var>) to be sampled periodically (whenever one of the threads
31*fdd8201dSApple OSS Distributionshappens to be running at the time of the kernel's "hardclock" interrupt).
32*fdd8201dSApple OSS DistributionsThe set of PC sample values obtained are saved in buffers which are sent to
33*fdd8201dSApple OSS Distributionsthe specified <var>reply_port</var> in <strong>receive_samples</strong> messages.
34*fdd8201dSApple OSS Distributions<h3>RETURN VALUES</h3>
35*fdd8201dSApple OSS Distributions<p>
36*fdd8201dSApple OSS DistributionsOnly generic errors apply.
37*fdd8201dSApple OSS Distributions<h3>RELATED INFORMATION</h3>
38*fdd8201dSApple OSS Distributions<p>
39*fdd8201dSApple OSS DistributionsFunctions:
40*fdd8201dSApple OSS Distributions<a href="thread_sample.html"><strong>thread_sample</strong></a>,
41*fdd8201dSApple OSS Distributions<a href="receive_samples.html"><strong>receive_samples</strong></a>.
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