diff options
Diffstat (limited to 'kern/timer.h')
| -rw-r--r-- | kern/timer.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/kern/timer.h b/kern/timer.h new file mode 100644 index 0000000..fe60e26 --- /dev/null +++ b/kern/timer.h @@ -0,0 +1,157 @@ +/* + * Mach Operating System + * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University + * All Rights Reserved. + * + * Permission to use, copy, modify and distribute this software and its + * documentation is hereby granted, provided that both the copyright + * notice and this permission notice appear in all copies of the + * software, derivative works or modified versions, and any portions + * thereof, and that both notices appear in supporting documentation. + * + * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" + * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR + * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. + * + * Carnegie Mellon requests users of this software to return to + * + * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU + * School of Computer Science + * Carnegie Mellon University + * Pittsburgh PA 15213-3890 + * + * any improvements or extensions that they make and grant Carnegie Mellon + * the rights to redistribute these changes. + */ + +#ifndef _KERN_TIMER_H_ +#define _KERN_TIMER_H_ + +#include <cpus.h> +#include <stat_time.h> + +#include <kern/macro_help.h> + +#if STAT_TIME +/* + * Statistical timer definitions - use microseconds in timer, seconds + * in high unit field. No adjustment needed to convert to time_value_t + * as a result. Service timers once an hour. + */ + +#define TIMER_RATE 1000000 +#define TIMER_HIGH_UNIT TIMER_RATE +#undef TIMER_ADJUST + +#else STAT_TIME +/* + * Machine dependent definitions based on hardware support. + */ + +#include <machine/timer.h> + +#endif STAT_TIME + +/* + * Definitions for accurate timers. high_bits_check is a copy of + * high_bits that allows reader to verify that values read are ok. + */ + +struct timer { + unsigned low_bits; + unsigned high_bits; + unsigned high_bits_check; + unsigned tstamp; +}; + +typedef struct timer timer_data_t; +typedef struct timer *timer_t; + +/* + * Mask to check if low_bits is in danger of overflowing + */ + +#define TIMER_LOW_FULL 0x80000000U + +/* + * Kernel timers and current timer array. [Exported] + */ + +extern timer_t current_timer[NCPUS]; +extern timer_data_t kernel_timer[NCPUS]; + +/* + * save structure for timer readings. This is used to save timer + * readings for elapsed time computations. + */ + +struct timer_save { + unsigned low; + unsigned high; +}; + +typedef struct timer_save timer_save_data_t, *timer_save_t; + +/* + * Exported kernel interface to timers + */ + +#if STAT_TIME +#define start_timer(timer) +#define timer_switch(timer) +#else STAT_TIME +extern void start_timer(); +extern void timer_switch(); +#endif STAT_TIME + +extern void timer_read(); +extern void thread_read_times(); +extern unsigned timer_delta(); + +#if STAT_TIME +/* + * Macro to bump timer values. + */ +#define timer_bump(timer, usec) \ +MACRO_BEGIN \ + (timer)->low_bits += usec; \ + if ((timer)->low_bits & TIMER_LOW_FULL) { \ + timer_normalize(timer); \ + } \ +MACRO_END + +#else STAT_TIME +/* + * Exported hardware interface to timers + */ +extern void time_trap_uentry(); +extern void time_trap_uexit(); +extern timer_t time_int_entry(); +extern void time_int_exit(); +#endif STAT_TIME + +/* + * TIMER_DELTA finds the difference between a timer and a saved value, + * and updates the saved value. Look at high_bits check field after + * reading low because that's the first written by a normalize + * operation; this isn't necessary for current usage because + * this macro is only used when the timer can't be normalized: + * thread is not running, or running thread calls it on itself at + * splsched(). + */ + +#define TIMER_DELTA(timer, save, result) \ +MACRO_BEGIN \ + register unsigned temp; \ + \ + temp = (timer).low_bits; \ + if ((save).high != (timer).high_bits_check) { \ + result += timer_delta(&(timer), &(save)); \ + } \ + else { \ + result += temp - (save).low; \ + (save).low = temp; \ + } \ +MACRO_END + +#endif _KERN_TIMER_H_ |