xref: /xnu-8792.61.2/osfmk/man/host_get_clock_control.html (revision 42e220869062b56f8d7d0726fd4c88954f87902c)
1*42e22086SApple OSS Distributions<h2>host_get_clock_control</h2>
2*42e22086SApple OSS Distributions<hr>
3*42e22086SApple OSS Distributions<p>
4*42e22086SApple OSS Distributions<strong>Function</strong> - Return a send right to a kernel clock's control port.
5*42e22086SApple OSS Distributions<h3>SYNOPSIS</h3>
6*42e22086SApple OSS Distributions<pre>
7*42e22086SApple OSS Distributions<strong>kern_return_t   host_get_clock_control</strong>
8*42e22086SApple OSS Distributions                <strong>(host_priv_t</strong>                          <var>host_priv</var>,
9*42e22086SApple OSS Distributions                 <strong>clock_id_t</strong>                                  <var>id</var>,
10*42e22086SApple OSS Distributions                 <strong>clock_ctrl_t</strong>                     <var>clock_control</var><strong>);</strong>
11*42e22086SApple OSS Distributions</pre>
12*42e22086SApple OSS Distributions<h3>PARAMETERS</h3>
13*42e22086SApple OSS Distributions<dl>
14*42e22086SApple OSS Distributions<p>
15*42e22086SApple OSS Distributions<dt> <var>host_priv</var>
16*42e22086SApple OSS Distributions<dd>
17*42e22086SApple OSS Distributions[in host-control send right]
18*42e22086SApple OSS DistributionsThe control port for the host owning the
19*42e22086SApple OSS Distributionsclock.
20*42e22086SApple OSS Distributions<p>
21*42e22086SApple OSS Distributions<dt> <var>id</var>
22*42e22086SApple OSS Distributions<dd>
23*42e22086SApple OSS Distributions[in scalar]
24*42e22086SApple OSS DistributionsThe identification of the desired kernel clock.  These values
25*42e22086SApple OSS Distributionsare defined in \*L<mach/clock_types.h>\*O.  Although an implementation
26*42e22086SApple OSS Distributionsmay define additional values, the following values are always defined
27*42e22086SApple OSS Distributions(although only the REALTIME clock is required to be implemented):
28*42e22086SApple OSS Distributions<dl>
29*42e22086SApple OSS Distributions<p>
30*42e22086SApple OSS Distributions<dt> <strong>REALTIME_CLOCK</strong>
31*42e22086SApple OSS Distributions<dd>
32*42e22086SApple OSS DistributionsA moderate resolution clock service that (typically) tracks
33*42e22086SApple OSS Distributionstime since the system last boot.
34*42e22086SApple OSS Distributions<p>
35*42e22086SApple OSS Distributions<dt> <strong>BATTERY_CLOCK</strong>
36*42e22086SApple OSS Distributions<dd>
37*42e22086SApple OSS DistributionsA (typically) low resolution clock (to the second) that
38*42e22086SApple OSS Distributionssurvives power failures or service outages.
39*42e22086SApple OSS Distributions<p>
40*42e22086SApple OSS Distributions<dt> <strong>HIGHRES_CLOCK</strong>
41*42e22086SApple OSS Distributions<dd>
42*42e22086SApple OSS DistributionsA high resolution clock.
43*42e22086SApple OSS Distributions</dl>
44*42e22086SApple OSS Distributions<p>
45*42e22086SApple OSS Distributions<dt> <var>clock_control</var>
46*42e22086SApple OSS Distributions<dd>
47*42e22086SApple OSS Distributions[out clock-control send right]
48*42e22086SApple OSS DistributionsControl port for the clock.
49*42e22086SApple OSS Distributions</dl>
50*42e22086SApple OSS Distributions<h3>DESCRIPTION</h3>
51*42e22086SApple OSS Distributions<p>
52*42e22086SApple OSS DistributionsThe <strong>host_get_clock_control</strong> function returns a send
53*42e22086SApple OSS Distributionsright to the control port for
54*42e22086SApple OSS Distributionsa kernel clock object.  This right is used to set the clock's
55*42e22086SApple OSS Distributionsresolution and time.
56*42e22086SApple OSS Distributions<h3>RETURN VALUES</h3>
57*42e22086SApple OSS Distributions<p>
58*42e22086SApple OSS DistributionsOnly generic errors apply.
59*42e22086SApple OSS Distributions<h3>RELATED INFORMATION</h3>
60*42e22086SApple OSS Distributions<p>
61*42e22086SApple OSS DistributionsFunctions:
62*42e22086SApple OSS Distributions<a href="clock_set_time.html"><strong>clock_set_time</strong></a>,
63*42e22086SApple OSS Distributions<a href="clock_set_attributes.html"><strong>clock_set_attributes</strong></a>,
64*42e22086SApple OSS Distributions<a href="host_get_clock_service.html"><strong>host_get_clock_service</strong></a>.
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