88 lines
3.5 KiB
C
88 lines
3.5 KiB
C
/* Watchdog timer management. These functions in this file provide a
|
|
* convenient interface to the timers library that manages a list of
|
|
* watchdog timers. All details of scheduling an alarm at the CLOCK task
|
|
* are hidden behind this interface.
|
|
*
|
|
* The entry points into this file are:
|
|
* init_timer: initialize a timer structure
|
|
* set_timer: reset and existing or set a new watchdog timer
|
|
* cancel_timer: remove a timer from the list of timers
|
|
* expire_timers: check for expired timers and run watchdog functions
|
|
*
|
|
*/
|
|
|
|
#include "syslib.h"
|
|
#include <timers.h>
|
|
|
|
PRIVATE timer_t *timers = NULL;
|
|
PRIVATE int expiring = 0;
|
|
|
|
/*===========================================================================*
|
|
* init_timer *
|
|
*===========================================================================*/
|
|
PUBLIC void init_timer(timer_t *tp)
|
|
{
|
|
tmr_inittimer(tp);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* set_timer *
|
|
*===========================================================================*/
|
|
PUBLIC void set_timer(timer_t *tp, int ticks, tmr_func_t watchdog, int arg)
|
|
{
|
|
int r;
|
|
clock_t now, prev_time = 0, next_time;
|
|
|
|
if ((r = getuptime(&now)) != OK)
|
|
panic("set_timer: couldn't get uptime");
|
|
|
|
/* Set timer argument and add timer to the list. */
|
|
tmr_arg(tp)->ta_int = arg;
|
|
prev_time = tmrs_settimer(&timers, tp, now+ticks, watchdog, &next_time);
|
|
|
|
/* Reschedule our synchronous alarm if necessary. */
|
|
if (expiring == 0 && (! prev_time || prev_time > next_time)) {
|
|
if (sys_setalarm(next_time, 1) != OK)
|
|
panic("set_timer: couldn't set alarm");
|
|
}
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* cancel_timer *
|
|
*===========================================================================*/
|
|
PUBLIC void cancel_timer(timer_t *tp)
|
|
{
|
|
clock_t next_time, prev_time;
|
|
prev_time = tmrs_clrtimer(&timers, tp, &next_time);
|
|
|
|
/* If the earliest timer has been removed, we have to set the alarm to
|
|
* the next timer, or cancel the alarm altogether if the last timer
|
|
* has been cancelled (next_time will be 0 then).
|
|
*/
|
|
if (expiring == 0 && (prev_time < next_time || ! next_time)) {
|
|
if (sys_setalarm(next_time, 1) != OK)
|
|
panic("cancel_timer: couldn't set alarm");
|
|
}
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* expire_timers *
|
|
*===========================================================================*/
|
|
PUBLIC void expire_timers(clock_t now)
|
|
{
|
|
clock_t next_time;
|
|
|
|
/* Check for expired timers. Use a global variable to indicate that
|
|
* watchdog functions are called, so that sys_setalarm() isn't called
|
|
* more often than necessary when set_timer or cancel_timer are called
|
|
* from these watchdog functions. */
|
|
expiring = 1;
|
|
tmrs_exptimers(&timers, now, &next_time);
|
|
expiring = 0;
|
|
|
|
/* Reschedule an alarm if necessary. */
|
|
if (next_time > 0) {
|
|
if (sys_setalarm(next_time, 1) != OK)
|
|
panic("expire_timers: couldn't set alarm");
|
|
}
|
|
}
|