d91f738bd8
Please note that this information is for use by system services only! The clock facility is not ready to be used directly by userland, and thus, this kernel page extension is NOT part of the userland ABI. For service programmers' convenience, change the prototype of the getticks(3) to return the uptime clock value directly, since the call can no longer fail. Correct the sys_times(2) reply message to use the right field type for the boot time. Restructure the kernel internals a bit so as to have all the clock stuff closer together. Change-Id: Ifc050b7bd253aecbe46e3bd7d7cc75bd86e45555
87 lines
3.4 KiB
C
87 lines
3.4 KiB
C
/* Watchdog timer management. These functions in this file provide a
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* convenient interface to the timers library that manages a list of
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* watchdog timers. All details of scheduling an alarm at the CLOCK task
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* are hidden behind this interface.
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*
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* The entry points into this file are:
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* init_timer: initialize a timer structure
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* set_timer: reset and existing or set a new watchdog timer
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* cancel_timer: remove a timer from the list of timers
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* expire_timers: check for expired timers and run watchdog functions
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*
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*/
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#include "syslib.h"
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#include <minix/timers.h>
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#include <minix/sysutil.h>
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static minix_timer_t *timers = NULL;
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static int expiring = 0;
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/*===========================================================================*
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* init_timer *
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*===========================================================================*/
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void init_timer(minix_timer_t *tp)
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{
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tmr_inittimer(tp);
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}
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/*===========================================================================*
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* set_timer *
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*===========================================================================*/
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void set_timer(minix_timer_t *tp, int ticks, tmr_func_t watchdog, int arg)
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{
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clock_t prev_time = 0, next_time;
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/* Set timer argument and add timer to the list. */
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tmr_arg(tp)->ta_int = arg;
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prev_time = tmrs_settimer(&timers, tp, getticks() + ticks, watchdog,
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&next_time);
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/* Reschedule our synchronous alarm if necessary. */
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if (expiring == 0 && (! prev_time || prev_time > next_time)) {
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if (sys_setalarm(next_time, 1) != OK)
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panic("set_timer: couldn't set alarm");
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}
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}
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/*===========================================================================*
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* cancel_timer *
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*===========================================================================*/
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void cancel_timer(minix_timer_t *tp)
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{
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clock_t next_time, prev_time;
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prev_time = tmrs_clrtimer(&timers, tp, &next_time);
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/* If the earliest timer has been removed, we have to set the alarm to
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* the next timer, or cancel the alarm altogether if the last timer
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* has been cancelled (next_time will be 0 then).
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*/
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if (expiring == 0 && (prev_time < next_time || ! next_time)) {
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if (sys_setalarm(next_time, 1) != OK)
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panic("cancel_timer: couldn't set alarm");
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}
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}
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/*===========================================================================*
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* expire_timers *
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*===========================================================================*/
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void expire_timers(clock_t now)
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{
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clock_t next_time;
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/* Check for expired timers. Use a global variable to indicate that
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* watchdog functions are called, so that sys_setalarm() isn't called
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* more often than necessary when set_timer or cancel_timer are called
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* from these watchdog functions. */
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expiring = 1;
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tmrs_exptimers(&timers, now, &next_time);
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expiring = 0;
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/* Reschedule an alarm if necessary. */
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if (next_time > 0) {
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if (sys_setalarm(next_time, 1) != OK)
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panic("expire_timers: couldn't set alarm");
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}
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}
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