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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
/* threadtest.c
* by: john stultz (johnstul@us.ibm.com)
* (C) Copyright IBM 2004, 2005, 2006, 2012
* Licensed under the GPLv2
*
* To build:
* $ gcc threadtest.c -o threadtest -lrt
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/time.h>
#include <pthread.h>
#ifdef KTEST
#include "../kselftest.h"
#else
static inline int ksft_exit_pass(void)
{
exit(0);
}
static inline int ksft_exit_fail(void)
{
exit(1);
}
#endif
/* serializes shared list access */
pthread_mutex_t list_lock = PTHREAD_MUTEX_INITIALIZER;
/* serializes console output */
pthread_mutex_t print_lock = PTHREAD_MUTEX_INITIALIZER;
#define MAX_THREADS 128
#define LISTSIZE 128
int done = 0;
struct timespec global_list[LISTSIZE];
int listcount = 0;
void checklist(struct timespec *list, int size)
{
int i, j;
struct timespec *a, *b;
/* scan the list */
for (i = 0; i < size-1; i++) {
a = &list[i];
b = &list[i+1];
/* look for any time inconsistencies */
if ((b->tv_sec <= a->tv_sec) &&
(b->tv_nsec < a->tv_nsec)) {
/* flag other threads */
done = 1;
/*serialize printing to avoid junky output*/
pthread_mutex_lock(&print_lock);
/* dump the list */
printf("\n");
for (j = 0; j < size; j++) {
if (j == i)
printf("---------------\n");
printf("%lu:%lu\n", list[j].tv_sec, list[j].tv_nsec);
if (j == i+1)
printf("---------------\n");
}
printf("[FAILED]\n");
pthread_mutex_unlock(&print_lock);
}
}
}
/* The shared thread shares a global list
* that each thread fills while holding the lock.
* This stresses clock syncronization across cpus.
*/
void *shared_thread(void *arg)
{
while (!done) {
/* protect the list */
pthread_mutex_lock(&list_lock);
/* see if we're ready to check the list */
if (listcount >= LISTSIZE) {
checklist(global_list, LISTSIZE);
listcount = 0;
}
clock_gettime(CLOCK_MONOTONIC, &global_list[listcount++]);
pthread_mutex_unlock(&list_lock);
}
return NULL;
}
/* Each independent thread fills in its own
* list. This stresses clock_gettime() lock contention.
*/
void *independent_thread(void *arg)
{
struct timespec my_list[LISTSIZE];
int count;
while (!done) {
/* fill the list */
for (count = 0; count < LISTSIZE; count++)
clock_gettime(CLOCK_MONOTONIC, &my_list[count]);
checklist(my_list, LISTSIZE);
}
return NULL;
}
int main(int argc, char **argv)
{
int thread_count = 1, i;
time_t start, now, runtime = 60;
char buf[255];
pthread_t pth[MAX_THREADS];
int opt;
void *tret;
int ret = 0;
void *(*thread)(void *) = shared_thread;
/* Process arguments */
while ((opt = getopt(argc, argv, "t:n:i")) != -1) {
switch (opt) {
case 't':
runtime = atoi(optarg);
break;
case 'n':
thread_count = atoi(optarg);
break;
case 'i':
thread = independent_thread;
printf("using independent threads\n");
break;
default:
printf("Usage: %s [-t <secs>] [-n <numthreads>] [-i]\n", argv[0]);
printf(" -t: time to run\n");
printf(" -n: number of threads\n");
printf(" -i: use independent threads\n");
return -1;
}
}
if (thread_count > MAX_THREADS)
thread_count = MAX_THREADS;
setbuf(stdout, NULL);
start = time(0);
strftime(buf, 255, "%a, %d %b %Y %T %z", localtime(&start));
printf("%s\n", buf);
printf("Testing consistency with %i threads for %ld seconds: ", thread_count, runtime);
/* spawn */
for (i = 0; i < thread_count; i++)
pthread_create(&pth[i], 0, thread, 0);
while (time(&now) < start + runtime) {
sleep(1);
if (done) {
ret = 1;
strftime(buf, 255, "%a, %d %b %Y %T %z", localtime(&now));
printf("%s\n", buf);
goto out;
}
}
printf("[OK]\n");
done = 1;
out:
/* wait */
for (i = 0; i < thread_count; i++)
pthread_join(pth[i], &tret);
/* die */
if (ret)
ksft_exit_fail();
return ksft_exit_pass();
}
|
