minix3/include/minix/timers.h

118 lines
4.4 KiB
C

/* This library provides generic watchdog timer management functionality.
* The functions operate on a timer queue provided by the caller. Note that
* the timers must use absolute time to allow sorting. The library provides:
*
* tmrs_settimer: (re)set a new watchdog timer in the timers queue
* tmrs_clrtimer: remove a timer from both the timers queue
* tmrs_exptimers: check for expired timers and run watchdog functions
*
* Author:
* Jorrit N. Herder <jnherder@cs.vu.nl>
* Adapted from tmr_settimer and tmr_clrtimer in src/kernel/clock.c.
* Last modified: September 30, 2004.
*/
#ifndef _MINIX_TIMERS_H
#define _MINIX_TIMERS_H
#include <limits.h>
#include <sys/types.h>
#include <minix/u64.h>
#include <minix/minlib.h>
#include <minix/endpoint.h>
struct minix_timer;
typedef void (*tmr_func_t)(struct minix_timer *tp);
typedef union { int ta_int; long ta_long; void *ta_ptr; } tmr_arg_t;
/* A minix_timer_t variable must be declare for each distinct timer to be used.
* The timers watchdog function and expiration time are automatically set
* by the library function tmrs_settimer, but its argument is not.
*/
typedef struct minix_timer
{
struct minix_timer *tmr_next; /* next in a timer chain */
clock_t tmr_exp_time; /* expiration time */
tmr_func_t tmr_func; /* function to call when expired */
tmr_arg_t tmr_arg; /* random argument */
} minix_timer_t;
/* Used when the timer is not active. */
#define TMR_NEVER ((clock_t) -1 < 0) ? ((clock_t) LONG_MAX) : ((clock_t) -1)
#undef TMR_NEVER
#define TMR_NEVER ((clock_t) LONG_MAX)
/* These definitions can be used to set or get data from a timer variable. */
#define tmr_arg(tp) (&(tp)->tmr_arg)
#define tmr_exp_time(tp) (&(tp)->tmr_exp_time)
/* Timers should be initialized once before they are being used. Be careful
* not to reinitialize a timer that is in a list of timers, or the chain
* will be broken.
*/
#define tmr_inittimer(tp) (void)((tp)->tmr_exp_time = TMR_NEVER, \
(tp)->tmr_next = NULL)
/* The following generic timer management functions are available. They
* can be used to operate on the lists of timers. Adding a timer to a list
* automatically takes care of removing it.
*/
clock_t tmrs_clrtimer(minix_timer_t **tmrs, minix_timer_t *tp, clock_t *new_head);
void tmrs_exptimers(minix_timer_t **tmrs, clock_t now, clock_t *new_head);
clock_t tmrs_settimer(minix_timer_t **tmrs, minix_timer_t *tp, clock_t exp_time,
tmr_func_t watchdog, clock_t *new_head);
#define PRINT_STATS(cum_spenttime, cum_instances) { \
if(ex64hi(cum_spenttime)) { util_stacktrace(); printf(" ( ??? %lu %lu)\n", \
ex64hi(cum_spenttime), ex64lo(cum_spenttime)); } \
printf("%s:%d,%lu,%lu\n", \
__FILE__, __LINE__, cum_instances, \
ex64lo(cum_spenttime)); \
}
#define RESET_STATS(starttime, cum_instances, cum_spenttime, cum_starttime) { \
cum_instances = 0; \
cum_starttime = starttime; \
cum_spenttime = make64(0,0); \
}
#define TIME_BLOCK_VAR(timed_code_block, time_interval) do { \
static u64_t _cum_spenttime, _cum_starttime; \
static int _cum_instances; \
u64_t _next_cum_spent, _starttime, _endtime, _dt, _cum_dt; \
u32_t _dt_micros; \
read_tsc_64(&_starttime); \
do { timed_code_block } while(0); \
read_tsc_64(&_endtime); \
_dt = _endtime - _starttime; \
if(_cum_instances == 0) { \
RESET_STATS(_starttime, _cum_instances, _cum_spenttime, _cum_starttime); \
} \
_next_cum_spent = add64(_cum_spenttime, _dt); \
if(ex64hi(_next_cum_spent)) { \
PRINT_STATS(_cum_spenttime, _cum_instances); \
RESET_STATS(_starttime, _cum_instances, _cum_spenttime, _cum_starttime); \
} \
_cum_spenttime = add64(_cum_spenttime, _dt); \
_cum_instances++; \
_cum_dt = _endtime - _cum_starttime; \
if(_cum_dt > make64(0, 120)) { \
PRINT_STATS(_cum_spenttime, _cum_instances); \
RESET_STATS(_starttime, _cum_instances, _cum_spenttime, _cum_starttime); \
} \
} while(0)
#define TIME_BLOCK(timed_code_block) TIME_BLOCK_VAR(timed_code_block, 100)
#define TIME_BLOCK_T(timed_code_block, t) TIME_BLOCK_VAR(timed_code_block, t)
/* Timers abstraction for system processes. This would be in minix/sysutil.h
* if it weren't for naming conflicts.
*/
void init_timer(minix_timer_t *tp);
void set_timer(minix_timer_t *tp, int ticks, tmr_func_t watchdog, int arg);
void cancel_timer(minix_timer_t *tp);
void expire_timers(clock_t now);
#endif /* _MINIX_TIMERS_H */