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23 .Nm systimer_init_periodic ,
24 .Nm systimer_init_periodic_nq ,
25 .Nm systimer_adjust_periodic ,
26 .Nm systimer_init_oneshot
27 .Nd periodic callbacks
31 .Fn systimer_init_periodic "systimer_t info" "void *func" "void *data" "int hz"
33 .Fn systimer_init_periodic_nq "systimer_t info" "void *func" "void *data" "int hz"
35 .Fn systimer_adjust_periodic "systimer_t info" "int hz"
37 .Fn systimer_init_oneshot "systimer_t info" "void *func" "void *data" "int us"
39 Systimers invoke callbacks at either fixed frequencies or after time delays.
40 The callbacks are invoked in an interrupt thread and should only be used
44 .Fn systimer_init_periodic
45 function initializes a systimer callback function to be called at frequency
49 argument is an allocated systimer structure; the
51 argument is the function to call, with argument
55 .Fn systimer_init_periodic_nq
56 function initializes a systimer callback function to be called at a frequency
59 .Fn systimer_init_periodic
61 .Fn systimer_init_periodic_nq
62 function's callback is only called once at a given time, even if delays caused
63 multiple time intervals to have occurred.
66 .Fn systimer_adjust_periodic
67 function changes the frequency at which a systimer's callback is invoked.
69 current time interval is not affected.
72 argument specifies the new frequency.
75 .Fn systimer_init_oneshot
76 function arranges for a systimer callback function
78 to be invoked with argument
84 A simple example of using a one-short systimer to call a function after a short
86 .Bd -literal -offset indent
88 static struct systimer short_st;
89 char *str = "goodbye!";
91 systimer_init_oneshot(&short_st, panic, str, 1000);
95 The systimer implementation is in
96 .Pa /sys/kern/kern_systimer.c .
100 Systimers first appeared in