1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/*
* 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 <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.
*/
/*
* TIMER_MAX is needed if a 32-bit rollover timer needs to be adjusted for
* maximum value.
*/
#undef TIMER_MAX
/*
* TIMER_RATE is the rate of the timer in ticks per second. It is used to
* calculate percent cpu usage.
*/
#define TIMER_RATE 1000000
/*
* TIMER_HIGH_UNIT is the unit for high_bits in terms of low_bits.
* Setting it to TIMER_RATE makes the high unit seconds.
*/
#define TIMER_HIGH_UNIT TIMER_RATE
/*
* TIMER_ADJUST is used to adjust the value of a timer after it has been
* copied into a time_value_t. No adjustment is needed if high_bits is in
* seconds.
*/
#undef TIMER_ADJUST
/*
* MACHINE_TIMER_ROUTINES should defined if the timer routines are
* implemented in machine-dependent code (e.g. assembly language).
*/
#undef MACHINE_TIMER_ROUTINES
#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_ */
|
