xref: /xnu-10002.41.9/osfmk/man/host_get_clock_control.html (revision 699cd48037512bf4380799317ca44ca453c82f57)
1*699cd480SApple OSS Distributions<h2>host_get_clock_control</h2>
2*699cd480SApple OSS Distributions<hr>
3*699cd480SApple OSS Distributions<p>
4*699cd480SApple OSS Distributions<strong>Function</strong> - Return a send right to a kernel clock's control port.
5*699cd480SApple OSS Distributions<h3>SYNOPSIS</h3>
6*699cd480SApple OSS Distributions<pre>
7*699cd480SApple OSS Distributions<strong>kern_return_t   host_get_clock_control</strong>
8*699cd480SApple OSS Distributions                <strong>(host_priv_t</strong>                          <var>host_priv</var>,
9*699cd480SApple OSS Distributions                 <strong>clock_id_t</strong>                                  <var>id</var>,
10*699cd480SApple OSS Distributions                 <strong>clock_ctrl_t</strong>                     <var>clock_control</var><strong>);</strong>
11*699cd480SApple OSS Distributions</pre>
12*699cd480SApple OSS Distributions<h3>PARAMETERS</h3>
13*699cd480SApple OSS Distributions<dl>
14*699cd480SApple OSS Distributions<p>
15*699cd480SApple OSS Distributions<dt> <var>host_priv</var>
16*699cd480SApple OSS Distributions<dd>
17*699cd480SApple OSS Distributions[in host-control send right]
18*699cd480SApple OSS DistributionsThe control port for the host owning the
19*699cd480SApple OSS Distributionsclock.
20*699cd480SApple OSS Distributions<p>
21*699cd480SApple OSS Distributions<dt> <var>id</var>
22*699cd480SApple OSS Distributions<dd>
23*699cd480SApple OSS Distributions[in scalar]
24*699cd480SApple OSS DistributionsThe identification of the desired kernel clock.  These values
25*699cd480SApple OSS Distributionsare defined in \*L<mach/clock_types.h>\*O.  Although an implementation
26*699cd480SApple OSS Distributionsmay define additional values, the following values are always defined
27*699cd480SApple OSS Distributions(although only the REALTIME clock is required to be implemented):
28*699cd480SApple OSS Distributions<dl>
29*699cd480SApple OSS Distributions<p>
30*699cd480SApple OSS Distributions<dt> <strong>REALTIME_CLOCK</strong>
31*699cd480SApple OSS Distributions<dd>
32*699cd480SApple OSS DistributionsA moderate resolution clock service that (typically) tracks
33*699cd480SApple OSS Distributionstime since the system last boot.
34*699cd480SApple OSS Distributions<p>
35*699cd480SApple OSS Distributions<dt> <strong>BATTERY_CLOCK</strong>
36*699cd480SApple OSS Distributions<dd>
37*699cd480SApple OSS DistributionsA (typically) low resolution clock (to the second) that
38*699cd480SApple OSS Distributionssurvives power failures or service outages.
39*699cd480SApple OSS Distributions<p>
40*699cd480SApple OSS Distributions<dt> <strong>HIGHRES_CLOCK</strong>
41*699cd480SApple OSS Distributions<dd>
42*699cd480SApple OSS DistributionsA high resolution clock.
43*699cd480SApple OSS Distributions</dl>
44*699cd480SApple OSS Distributions<p>
45*699cd480SApple OSS Distributions<dt> <var>clock_control</var>
46*699cd480SApple OSS Distributions<dd>
47*699cd480SApple OSS Distributions[out clock-control send right]
48*699cd480SApple OSS DistributionsControl port for the clock.
49*699cd480SApple OSS Distributions</dl>
50*699cd480SApple OSS Distributions<h3>DESCRIPTION</h3>
51*699cd480SApple OSS Distributions<p>
52*699cd480SApple OSS DistributionsThe <strong>host_get_clock_control</strong> function returns a send
53*699cd480SApple OSS Distributionsright to the control port for
54*699cd480SApple OSS Distributionsa kernel clock object.  This right is used to set the clock's
55*699cd480SApple OSS Distributionsresolution and time.
56*699cd480SApple OSS Distributions<h3>RETURN VALUES</h3>
57*699cd480SApple OSS Distributions<p>
58*699cd480SApple OSS DistributionsOnly generic errors apply.
59*699cd480SApple OSS Distributions<h3>RELATED INFORMATION</h3>
60*699cd480SApple OSS Distributions<p>
61*699cd480SApple OSS DistributionsFunctions:
62*699cd480SApple OSS Distributions<a href="clock_set_time.html"><strong>clock_set_time</strong></a>,
63*699cd480SApple OSS Distributions<a href="clock_set_attributes.html"><strong>clock_set_attributes</strong></a>,
64*699cd480SApple OSS Distributions<a href="host_get_clock_service.html"><strong>host_get_clock_service</strong></a>.
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