osfmk/man/clock_map_time.html

   1 <h2>clock_map_time</h2>
   2 <hr>
   3 <p>
   4 <strong>Function</strong> - Return a memory object that maps a clock.
   5 <h3>SYNOPSIS</h3>
   6 <pre>
   7 <strong>kern_return_t   clock_map_time</strong>
   8                 <strong>(clock_t</strong>                             <var>clock_name</var>,
   9                  <strong>memory_object_t</strong>                   <var>clock_memory</var><strong>);</strong>
  10 </pre>
  11 <h3>PARAMETERS</h3>
  12 <dl>
  13 <p>
  14 <dt> <var>clock_name</var>
  15 <dd>
  16 [in clock-name send right]
  17 The name (or control) port for the clock.
  18 <p>
  19 <dt> <var>clock_memory</var>
  20 <dd>
  21 [out memory-object-representative send right]
  22 Mapped clock time
  23 memory object representative.
  24 </dl>
  25 <h3>DESCRIPTION</h3>
  26 <p>
  27 The <strong>clock_map_time</strong> function returns a memory object representative port
  28 representing read access to a memory object that contains (at offset zero) a
  29 mapped version of the clock time (structure <strong>mapped_tvalspec</strong>).
  30 The returned right is suitable as an argument for <strong>vm_map</strong>.
  31 <h3>NOTES</h3>
  32 <p>
  33 Not all clocks provide this service, but the REALTIME clock must.
  34 <h3>RETURN VALUES</h3>
  35 <dl>
  36 <p>
  37 <dt> <strong>KERN_FAILURE</strong>
  38 <dd>
  39 The specified clock does not provide this service.
  40 </dl>
  41 <h3>RELATED INFORMATION</h3>
  42 <p>
  43 Functions:
  44 <a href="host_get_clock_service.html"><strong>host_get_clock_service</strong></a>,
  45 <a href="clock_get_attributes.html"><strong>clock_get_attributes</strong></a>,
  46 <a href="clock_get_time.html"><strong>clock_get_time</strong></a>,
  47 <a href="clock_sleep.html"><strong>clock_sleep</strong></a>,
  48 <a href="clock_alarm.html"><strong>clock_alarm</strong></a>.
  49 <p>
  50 Data Structures:
  51 <a href="mapped_tvalspec.html"><strong>mapped_tvalspec</strong></a>.