xref: /xnu-8792.81.2/osfmk/man/host_get_clock_control.html (revision 19c3b8c28c31cb8130e034cfb5df6bf9ba342d90)
1*19c3b8c2SApple OSS Distributions<h2>host_get_clock_control</h2>
2*19c3b8c2SApple OSS Distributions<hr>
3*19c3b8c2SApple OSS Distributions<p>
4*19c3b8c2SApple OSS Distributions<strong>Function</strong> - Return a send right to a kernel clock's control port.
5*19c3b8c2SApple OSS Distributions<h3>SYNOPSIS</h3>
6*19c3b8c2SApple OSS Distributions<pre>
7*19c3b8c2SApple OSS Distributions<strong>kern_return_t   host_get_clock_control</strong>
8*19c3b8c2SApple OSS Distributions                <strong>(host_priv_t</strong>                          <var>host_priv</var>,
9*19c3b8c2SApple OSS Distributions                 <strong>clock_id_t</strong>                                  <var>id</var>,
10*19c3b8c2SApple OSS Distributions                 <strong>clock_ctrl_t</strong>                     <var>clock_control</var><strong>);</strong>
11*19c3b8c2SApple OSS Distributions</pre>
12*19c3b8c2SApple OSS Distributions<h3>PARAMETERS</h3>
13*19c3b8c2SApple OSS Distributions<dl>
14*19c3b8c2SApple OSS Distributions<p>
15*19c3b8c2SApple OSS Distributions<dt> <var>host_priv</var>
16*19c3b8c2SApple OSS Distributions<dd>
17*19c3b8c2SApple OSS Distributions[in host-control send right]
18*19c3b8c2SApple OSS DistributionsThe control port for the host owning the
19*19c3b8c2SApple OSS Distributionsclock.
20*19c3b8c2SApple OSS Distributions<p>
21*19c3b8c2SApple OSS Distributions<dt> <var>id</var>
22*19c3b8c2SApple OSS Distributions<dd>
23*19c3b8c2SApple OSS Distributions[in scalar]
24*19c3b8c2SApple OSS DistributionsThe identification of the desired kernel clock.  These values
25*19c3b8c2SApple OSS Distributionsare defined in \*L<mach/clock_types.h>\*O.  Although an implementation
26*19c3b8c2SApple OSS Distributionsmay define additional values, the following values are always defined
27*19c3b8c2SApple OSS Distributions(although only the REALTIME clock is required to be implemented):
28*19c3b8c2SApple OSS Distributions<dl>
29*19c3b8c2SApple OSS Distributions<p>
30*19c3b8c2SApple OSS Distributions<dt> <strong>REALTIME_CLOCK</strong>
31*19c3b8c2SApple OSS Distributions<dd>
32*19c3b8c2SApple OSS DistributionsA moderate resolution clock service that (typically) tracks
33*19c3b8c2SApple OSS Distributionstime since the system last boot.
34*19c3b8c2SApple OSS Distributions<p>
35*19c3b8c2SApple OSS Distributions<dt> <strong>BATTERY_CLOCK</strong>
36*19c3b8c2SApple OSS Distributions<dd>
37*19c3b8c2SApple OSS DistributionsA (typically) low resolution clock (to the second) that
38*19c3b8c2SApple OSS Distributionssurvives power failures or service outages.
39*19c3b8c2SApple OSS Distributions<p>
40*19c3b8c2SApple OSS Distributions<dt> <strong>HIGHRES_CLOCK</strong>
41*19c3b8c2SApple OSS Distributions<dd>
42*19c3b8c2SApple OSS DistributionsA high resolution clock.
43*19c3b8c2SApple OSS Distributions</dl>
44*19c3b8c2SApple OSS Distributions<p>
45*19c3b8c2SApple OSS Distributions<dt> <var>clock_control</var>
46*19c3b8c2SApple OSS Distributions<dd>
47*19c3b8c2SApple OSS Distributions[out clock-control send right]
48*19c3b8c2SApple OSS DistributionsControl port for the clock.
49*19c3b8c2SApple OSS Distributions</dl>
50*19c3b8c2SApple OSS Distributions<h3>DESCRIPTION</h3>
51*19c3b8c2SApple OSS Distributions<p>
52*19c3b8c2SApple OSS DistributionsThe <strong>host_get_clock_control</strong> function returns a send
53*19c3b8c2SApple OSS Distributionsright to the control port for
54*19c3b8c2SApple OSS Distributionsa kernel clock object.  This right is used to set the clock's
55*19c3b8c2SApple OSS Distributionsresolution and time.
56*19c3b8c2SApple OSS Distributions<h3>RETURN VALUES</h3>
57*19c3b8c2SApple OSS Distributions<p>
58*19c3b8c2SApple OSS DistributionsOnly generic errors apply.
59*19c3b8c2SApple OSS Distributions<h3>RELATED INFORMATION</h3>
60*19c3b8c2SApple OSS Distributions<p>
61*19c3b8c2SApple OSS DistributionsFunctions:
62*19c3b8c2SApple OSS Distributions<a href="clock_set_time.html"><strong>clock_set_time</strong></a>,
63*19c3b8c2SApple OSS Distributions<a href="clock_set_attributes.html"><strong>clock_set_attributes</strong></a>,
64*19c3b8c2SApple OSS Distributions<a href="host_get_clock_service.html"><strong>host_get_clock_service</strong></a>.
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