projects / apple / xnu.git / blame
| Commit | Line | Data |
|---|---|---|
| 13fec989 A |
1 | <h2>clock_alarm</h2> |
| 2 | <hr> | |
| 3 | <p> | |
| 4 | <strong>Function</strong> - Set off an alarm. | |
| 5 | <h3>SYNOPSIS</h3> | |
| 6 | <pre> | |
| 7 | <strong>kern_return_t clock_alarm</strong> | |
| 8 | <strong>(clock_t</strong> <var>clock_name</var>, | |
| 9 | <strong>alarm_type_t</strong> <var>alarm_type</var>, | |
| 10 | <strong>tvalspec_t</strong> <var>alarm_time</var>, | |
| 11 | <strong>mach_port_t</strong> <var>alarm_reply_port</var><strong>);</strong> | |
| 12 | </pre> | |
| 13 | <h3>PARAMETERS</h3> | |
| 14 | <dl> | |
| 15 | <p> | |
| 16 | <dt> <var>clock_name</var> | |
| 17 | <dd> | |
| 18 | [in clock-name send right] | |
| 19 | The name (or control) port for the clock. | |
| 20 | <p> | |
| 21 | <dt> <var>alarm_type</var> | |
| 22 | <dd> | |
| 23 | [in scalar] | |
| 24 | How to interpret the <var>alarm_time</var> value: | |
| 25 | <dl> | |
| 26 | <p> | |
| 27 | <dt> <strong>TIME_RELATIVE</strong> | |
| 28 | <dd> | |
| 29 | Interpret the alarm time as relative to the current time. | |
| 30 | <p> | |
| 31 | <dt> <strong>TIME_ABSOLUTE</strong> | |
| 32 | <dd> | |
| 33 | Interpret the alarm time as an absolute time. | |
| 34 | </dl> | |
| 35 | <p> | |
| 36 | <dt> <var>alarm_time</var> | |
| 37 | <dd> | |
| 38 | [in structure] | |
| 39 | The time when the alarm is to be sent. | |
| 40 | <p> | |
| 41 | <dt> <var>alarm_reply_port</var> | |
| 42 | <dd> | |
| 43 | [in alarm receive (to be converted to send-once) right] | |
| 44 | A port into | |
| 45 | which the alarm message is to be sent. | |
| 46 | </dl> | |
| 47 | <h3>DESCRIPTION</h3> | |
| 48 | <p> | |
| 49 | The <strong>clock_alarm</strong> function requests that a clock send | |
| 50 | an alarm message to a | |
| 51 | specified port at a given future time. The alarm message is specified by the | |
| 52 | <strong>clock_alarm_reply</strong> server interface. | |
| 53 | <h3>NOTES</h3> | |
| 54 | <p> | |
| 55 | If the specified alarm time is in the past, the alarm message | |
| 56 | is sent immediately | |
| 57 | and time-stamped with the current time. Otherwise, the alarm is queued and | |
| 58 | delivered at the specified alarm time and time-stamped at that time. | |
| 59 | <p> | |
| 60 | The alarm will be serviced at the service time nearest the specified | |
| 61 | alarm time | |
| 62 | as governed by the current clock alarm resolution. | |
| 63 | <p> | |
| 64 | Not all clocks implement this service, but the REALTIME clock must. If the | |
| 65 | clock does not provide this service, this call is ignored. | |
| 66 | <h3>RETURN VALUES</h3> | |
| 67 | <p> | |
| 68 | Only generic errors apply. | |
| 69 | <h3>RELATED INFORMATION</h3> | |
| 70 | <p> | |
| 71 | Functions: | |
| 72 | <a href="host_get_clock_service.html"><strong>host_get_clock_service</strong></a>, | |
| 73 | <a href="clock_get_attributes.html"><strong>clock_get_attributes</strong></a>, | |
| 74 | <a href="clock_get_time.html"><strong>clock_get_time</strong></a>, | |
| 75 | <a href="clock_sleep.html"><strong>clock_sleep</strong></a>, | |
| 76 | <a href="clock_alarm_reply.html"><strong>clock_alarm_reply</strong></a>. | |
| 77 | <p> | |
| 78 | Data Structures: | |
| 79 | <a href="tvalspec.html"><strong>tvalspec</strong></a>. |