time.c revision 6796209a7e3d39522b0f5599aba277809786335e 
1#include <time.h>
2#include <sys/time.h>
3
4#include "fio.h"
5
6unsigned long utime_since(struct timeval *s, struct timeval *e)
7{
8	double sec, usec;
9
10	sec = e->tv_sec - s->tv_sec;
11	usec = e->tv_usec - s->tv_usec;
12	if (sec > 0 && usec < 0) {
13		sec--;
14		usec += 1000000;
15	}
16
17	sec *= (double) 1000000;
18
19	return sec + usec;
20}
21
22static unsigned long utime_since_now(struct timeval *s)
23{
24	struct timeval t;
25
26	gettimeofday(&t, NULL);
27	return utime_since(s, &t);
28}
29
30unsigned long mtime_since(struct timeval *s, struct timeval *e)
31{
32	double sec, usec;
33
34	sec = e->tv_sec - s->tv_sec;
35	usec = e->tv_usec - s->tv_usec;
36	if (sec > 0 && usec < 0) {
37		sec--;
38		usec += 1000000;
39	}
40
41	sec *= (double) 1000;
42	usec /= (double) 1000;
43
44	return sec + usec;
45}
46
47unsigned long mtime_since_now(struct timeval *s)
48{
49	struct timeval t;
50
51	gettimeofday(&t, NULL);
52	return mtime_since(s, &t);
53}
54
55unsigned long time_since_now(struct timeval *s)
56{
57	return mtime_since_now(s) / 1000;
58}
59
60/*
61 * busy looping version for the last few usec
62 */
63static void __usec_sleep(unsigned int usec)
64{
65	struct timeval start;
66
67	gettimeofday(&start, NULL);
68	while (utime_since_now(&start) < usec)
69		nop;
70}
71
72void usec_sleep(struct thread_data *td, unsigned long usec)
73{
74	struct timespec req, rem;
75
76	req.tv_sec = usec / 1000000;
77	req.tv_nsec = usec * 1000 - req.tv_sec * 1000000;
78
79	do {
80		if (usec < 5000) {
81			__usec_sleep(usec);
82			break;
83		}
84
85		rem.tv_sec = rem.tv_nsec = 0;
86		if (nanosleep(&req, &rem) < 0)
87			break;
88
89		if ((rem.tv_sec + rem.tv_nsec) == 0)
90			break;
91
92		req.tv_nsec = rem.tv_nsec;
93		req.tv_sec = rem.tv_sec;
94
95		usec = rem.tv_sec * 1000000 + rem.tv_nsec / 1000;
96	} while (!td->terminate);
97}
98
99void rate_throttle(struct thread_data *td, unsigned long time_spent,
100		   unsigned int bytes)
101{
102	unsigned long usec_cycle;
103
104	if (!td->rate)
105		return;
106
107	usec_cycle = td->rate_usec_cycle * (bytes / td->min_bs);
108
109	if (time_spent < usec_cycle) {
110		unsigned long s = usec_cycle - time_spent;
111
112		td->rate_pending_usleep += s;
113		if (td->rate_pending_usleep >= 100000) {
114			usec_sleep(td, td->rate_pending_usleep);
115			td->rate_pending_usleep = 0;
116		}
117	} else {
118		long overtime = time_spent - usec_cycle;
119
120		td->rate_pending_usleep -= overtime;
121	}
122}
123