xref: /xnu-8796.121.2/osfmk/man/host_get_clock_service.html (revision c54f35ca767986246321eb901baf8f5ff7923f6a)
1*c54f35caSApple OSS Distributions<h2>host_get_clock_service</h2>
2*c54f35caSApple OSS Distributions<hr>
3*c54f35caSApple OSS Distributions<p>
4*c54f35caSApple OSS Distributions<strong>Function</strong> - Return a send right to a kernel clock's service port.
5*c54f35caSApple OSS Distributions<h3>SYNOPSIS</h3>
6*c54f35caSApple OSS Distributions<pre>
7*c54f35caSApple OSS Distributions<strong>kern_return_t   host_get_clock_service</strong>
8*c54f35caSApple OSS Distributions                <strong>(host_t</strong>                                    <var>host</var>,
9*c54f35caSApple OSS Distributions                 <strong>clock_id_t</strong>                                  <var>id</var>,
10*c54f35caSApple OSS Distributions                 <strong>clock_t</strong>                             <var>clock_name</var><strong>);</strong>
11*c54f35caSApple OSS Distributions</pre>
12*c54f35caSApple OSS Distributions<h3>PARAMETERS</h3>
13*c54f35caSApple OSS Distributions<dl>
14*c54f35caSApple OSS Distributions<p>
15*c54f35caSApple OSS Distributions<dt> <var>host</var>
16*c54f35caSApple OSS Distributions<dd>
17*c54f35caSApple OSS Distributions[in host-name send right]
18*c54f35caSApple OSS DistributionsThe name (or control) port for the host
19*c54f35caSApple OSS Distributionsowning the clock.
20*c54f35caSApple OSS Distributions<p>
21*c54f35caSApple OSS Distributions<dt> <var>id</var>
22*c54f35caSApple OSS Distributions<dd>
23*c54f35caSApple OSS Distributions[in scalar]
24*c54f35caSApple OSS DistributionsThe identification of the desired kernel clock.  These values
25*c54f35caSApple OSS Distributionsare defined in \*L<mach/clock_types.h>\*O.  Although an implementation
26*c54f35caSApple OSS Distributionsmay define additional values, the following values are always defined
27*c54f35caSApple OSS Distributions(although only the REALTIME clock is required to be implemented):
28*c54f35caSApple OSS Distributions<dl>
29*c54f35caSApple OSS Distributions<p>
30*c54f35caSApple OSS Distributions<dt> <strong>REALTIME_CLOCK</strong>
31*c54f35caSApple OSS Distributions<dd>
32*c54f35caSApple OSS DistributionsA moderate resolution clock service that (typically) tracks
33*c54f35caSApple OSS Distributionstime since the system last boot.
34*c54f35caSApple OSS Distributions<p>
35*c54f35caSApple OSS Distributions<dt> <strong>BATTERY_CLOCK</strong>
36*c54f35caSApple OSS Distributions<dd>
37*c54f35caSApple OSS DistributionsA (typically) low resolution clock (to the second) that
38*c54f35caSApple OSS Distributionssurvives power failures or service outages.
39*c54f35caSApple OSS Distributions<p>
40*c54f35caSApple OSS Distributions<dt> <strong>HIGHRES_CLOCK</strong>
41*c54f35caSApple OSS Distributions<dd>
42*c54f35caSApple OSS DistributionsA high resolution clock.
43*c54f35caSApple OSS Distributions</dl>
44*c54f35caSApple OSS Distributions<p>
45*c54f35caSApple OSS Distributions<dt> <var>clock_name</var>
46*c54f35caSApple OSS Distributions<dd>
47*c54f35caSApple OSS Distributions[out clock-name send right]
48*c54f35caSApple OSS DistributionsName port for the clock.
49*c54f35caSApple OSS Distributions</dl>
50*c54f35caSApple OSS Distributions<h3>DESCRIPTION</h3>
51*c54f35caSApple OSS Distributions<p>
52*c54f35caSApple OSS DistributionsThe <strong>host_get_clock_service</strong> function returns a send
53*c54f35caSApple OSS Distributionsright to the name port for a
54*c54f35caSApple OSS Distributionskernel clock object.  This right is used to get the time and
55*c54f35caSApple OSS Distributionsresolutions of the
56*c54f35caSApple OSS Distributionsclock and to set clock alarms.
57*c54f35caSApple OSS Distributions<h3>RETURN VALUES</h3>
58*c54f35caSApple OSS Distributions<p>
59*c54f35caSApple OSS DistributionsOnly generic errors apply.
60*c54f35caSApple OSS Distributions<h3>RELATED INFORMATION</h3>
61*c54f35caSApple OSS Distributions<p>
62*c54f35caSApple OSS DistributionsFunctions:
63*c54f35caSApple OSS Distributions<a href="clock_get_time.html"><strong>clock_get_time</strong></a>,
64*c54f35caSApple OSS Distributions<a href="clock_get_attributes.html"><strong>clock_get_attributes</strong></a>,
65*c54f35caSApple OSS Distributions<a href="clock_map_time.html"><strong>clock_map_time</strong></a>,
66*c54f35caSApple OSS Distributions<a href="clock_sleep.html"><strong>clock_sleep</strong></a>,
67*c54f35caSApple OSS Distributions<a href="clock_alarm.html"><strong>clock_alarm</strong></a>,
68*c54f35caSApple OSS Distributions<a href="host_get_clock_control.html"><strong>host_get_clock_control</strong></a>.
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