xref: /xnu-10002.1.13/osfmk/man/clock_set_attributes.html (revision 1031c584a5e37aff177559b9f69dbd3c8c3fd30a)
1*1031c584SApple OSS Distributions<h2>clock_set_attributes</h2>
2*1031c584SApple OSS Distributions<hr>
3*1031c584SApple OSS Distributions<p>
4*1031c584SApple OSS Distributions<strong>Function</strong> - Set a particular clock's attributes.
5*1031c584SApple OSS Distributions<h3>SYNOPSIS</h3>
6*1031c584SApple OSS Distributions<pre>
7*1031c584SApple OSS Distributions<strong>kern_return_t   clock_set_attributes</strong>
8*1031c584SApple OSS Distributions                <strong>(clock_ctrl_t</strong>                     <var>clock_control</var>,
9*1031c584SApple OSS Distributions                 <strong>clock_flavor_t</strong>                          <var>flavor</var>,
10*1031c584SApple OSS Distributions                 <strong>clock_attr_t</strong>                         <var>attribute</var>,
11*1031c584SApple OSS Distributions                 <strong>clock_control</strong>                  <var>attribute_count</var><strong>);</strong>
12*1031c584SApple OSS Distributions</pre>
13*1031c584SApple OSS Distributions<h3>PARAMETERS</h3>
14*1031c584SApple OSS Distributions<dl>
15*1031c584SApple OSS Distributions<p>
16*1031c584SApple OSS Distributions<dt> <var>clock_control</var>
17*1031c584SApple OSS Distributions<dd>
18*1031c584SApple OSS Distributions[in clock-control send right]
19*1031c584SApple OSS DistributionsThe control port for the clock.
20*1031c584SApple OSS Distributions<p>
21*1031c584SApple OSS Distributions<dt> <var>flavor</var>
22*1031c584SApple OSS Distributions<dd>
23*1031c584SApple OSS Distributions[in scalar]
24*1031c584SApple OSS DistributionsType of information to be set.  Defined values are:
25*1031c584SApple OSS Distributions<dl>
26*1031c584SApple OSS Distributions<p>
27*1031c584SApple OSS Distributions<dt> <strong>CLOCK_ALARM_CURRES</strong>
28*1031c584SApple OSS Distributions<dd>
29*1031c584SApple OSS DistributionsThe resolution, in nanoseconds, at which clock alarm and
30*1031c584SApple OSS Distributionssleep timers are currently serviced.  Increasing the current
31*1031c584SApple OSS Distributionsresolution will have no impact on any pending clock alarms (i.e.
32*1031c584SApple OSS Distributionsthey will go off as originally scheduled).  Decreasing the
33*1031c584SApple OSS Distributionscurrent resolution will truncate any pending alarms to the
34*1031c584SApple OSS Distributionsgranularity of the new current resolution.  This value must be a
35*1031c584SApple OSS Distributionsmultiple of the minimum resolution and not greater than the
36*1031c584SApple OSS Distributionsmaximum resolution of the clock.
37*1031c584SApple OSS Distributions</dl>
38*1031c584SApple OSS Distributions<p>
39*1031c584SApple OSS Distributions<dt> <var>attribute</var>
40*1031c584SApple OSS Distributions<dd>
41*1031c584SApple OSS Distributions[pointer to in scalar]
42*1031c584SApple OSS DistributionsNew attribute.
43*1031c584SApple OSS Distributions<p>
44*1031c584SApple OSS Distributions<dt> <var>attribute_count</var>
45*1031c584SApple OSS Distributions<dd>
46*1031c584SApple OSS Distributions[in scalar]
47*1031c584SApple OSS DistributionsThe size of the buffer (in natural-sized units).
48*1031c584SApple OSS Distributions</dl>
49*1031c584SApple OSS Distributions<h3>DESCRIPTION</h3>
50*1031c584SApple OSS Distributions<p>
51*1031c584SApple OSS DistributionsThe <strong>clock_set_attributes</strong> function sets attributes of
52*1031c584SApple OSS Distributionsa clock's operation.
53*1031c584SApple OSS Distributions<h3>NOTES</h3>
54*1031c584SApple OSS Distributions<p>
55*1031c584SApple OSS DistributionsThe main reason a clock's current resolution would not always equal its
56*1031c584SApple OSS Distributionsminimum resolution is because the overhead of sustaining the
57*1031c584SApple OSS Distributionsminimum resolution,
58*1031c584SApple OSS Distributionswhen it is not needed by any existing alarm service client, may be prohibitive
59*1031c584SApple OSS Distributionsfor a given hardware platform and underlying clock device.
60*1031c584SApple OSS Distributions<h3>RETURN VALUES</h3>
61*1031c584SApple OSS Distributions<p>
62*1031c584SApple OSS DistributionsOnly generic errors apply.
63*1031c584SApple OSS Distributions<h3>RELATED INFORMATION</h3>
64*1031c584SApple OSS Distributions<p>
65*1031c584SApple OSS DistributionsFunctions:
66*1031c584SApple OSS Distributions<a href="host_get_clock_control.html"><strong>host_get_clock_control</strong></a>,
67*1031c584SApple OSS Distributions<a href="clock_set_time.html"><strong>clock_set_time</strong></a>,
68*1031c584SApple OSS Distributions<a href="clock_get_attributes.html"><strong>clock_get_attributes</strong></a>.
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