| 1 | /* threadtest.c |
| 2 | * by: john stultz (johnstul@us.ibm.com) |
| 3 | * (C) Copyright IBM 2004, 2005, 2006, 2012 |
| 4 | * Licensed under the GPLv2 |
| 5 | * |
| 6 | * To build: |
| 7 | * $ gcc threadtest.c -o threadtest -lrt |
| 8 | * |
| 9 | * This program is free software: you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation, either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | */ |
| 19 | #include <stdio.h> |
| 20 | #include <unistd.h> |
| 21 | #include <stdlib.h> |
| 22 | #include <sys/time.h> |
| 23 | #include <pthread.h> |
| 24 | #ifdef KTEST |
| 25 | #include "../kselftest.h" |
| 26 | #else |
| 27 | static inline int ksft_exit_pass(void) |
| 28 | { |
| 29 | exit(0); |
| 30 | } |
| 31 | static inline int ksft_exit_fail(void) |
| 32 | { |
| 33 | exit(1); |
| 34 | } |
| 35 | #endif |
| 36 | |
| 37 | |
| 38 | /* serializes shared list access */ |
| 39 | pthread_mutex_t list_lock = PTHREAD_MUTEX_INITIALIZER; |
| 40 | /* serializes console output */ |
| 41 | pthread_mutex_t print_lock = PTHREAD_MUTEX_INITIALIZER; |
| 42 | |
| 43 | |
| 44 | #define MAX_THREADS 128 |
| 45 | #define LISTSIZE 128 |
| 46 | |
| 47 | int done = 0; |
| 48 | |
| 49 | struct timespec global_list[LISTSIZE]; |
| 50 | int listcount = 0; |
| 51 | |
| 52 | |
| 53 | void checklist(struct timespec *list, int size) |
| 54 | { |
| 55 | int i, j; |
| 56 | struct timespec *a, *b; |
| 57 | |
| 58 | /* scan the list */ |
| 59 | for (i = 0; i < size-1; i++) { |
| 60 | a = &list[i]; |
| 61 | b = &list[i+1]; |
| 62 | |
| 63 | /* look for any time inconsistencies */ |
| 64 | if ((b->tv_sec <= a->tv_sec) && |
| 65 | (b->tv_nsec < a->tv_nsec)) { |
| 66 | |
| 67 | /* flag other threads */ |
| 68 | done = 1; |
| 69 | |
| 70 | /*serialize printing to avoid junky output*/ |
| 71 | pthread_mutex_lock(&print_lock); |
| 72 | |
| 73 | /* dump the list */ |
| 74 | printf("\n"); |
| 75 | for (j = 0; j < size; j++) { |
| 76 | if (j == i) |
| 77 | printf("---------------\n"); |
| 78 | printf("%lu:%lu\n", list[j].tv_sec, list[j].tv_nsec); |
| 79 | if (j == i+1) |
| 80 | printf("---------------\n"); |
| 81 | } |
| 82 | printf("[FAILED]\n"); |
| 83 | |
| 84 | pthread_mutex_unlock(&print_lock); |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | /* The shared thread shares a global list |
| 90 | * that each thread fills while holding the lock. |
| 91 | * This stresses clock syncronization across cpus. |
| 92 | */ |
| 93 | void *shared_thread(void *arg) |
| 94 | { |
| 95 | while (!done) { |
| 96 | /* protect the list */ |
| 97 | pthread_mutex_lock(&list_lock); |
| 98 | |
| 99 | /* see if we're ready to check the list */ |
| 100 | if (listcount >= LISTSIZE) { |
| 101 | checklist(global_list, LISTSIZE); |
| 102 | listcount = 0; |
| 103 | } |
| 104 | clock_gettime(CLOCK_MONOTONIC, &global_list[listcount++]); |
| 105 | |
| 106 | pthread_mutex_unlock(&list_lock); |
| 107 | } |
| 108 | return NULL; |
| 109 | } |
| 110 | |
| 111 | |
| 112 | /* Each independent thread fills in its own |
| 113 | * list. This stresses clock_gettime() lock contention. |
| 114 | */ |
| 115 | void *independent_thread(void *arg) |
| 116 | { |
| 117 | struct timespec my_list[LISTSIZE]; |
| 118 | int count; |
| 119 | |
| 120 | while (!done) { |
| 121 | /* fill the list */ |
| 122 | for (count = 0; count < LISTSIZE; count++) |
| 123 | clock_gettime(CLOCK_MONOTONIC, &my_list[count]); |
| 124 | checklist(my_list, LISTSIZE); |
| 125 | } |
| 126 | return NULL; |
| 127 | } |
| 128 | |
| 129 | #define DEFAULT_THREAD_COUNT 8 |
| 130 | #define DEFAULT_RUNTIME 30 |
| 131 | |
| 132 | int main(int argc, char **argv) |
| 133 | { |
| 134 | int thread_count, i; |
| 135 | time_t start, now, runtime; |
| 136 | char buf[255]; |
| 137 | pthread_t pth[MAX_THREADS]; |
| 138 | int opt; |
| 139 | void *tret; |
| 140 | int ret = 0; |
| 141 | void *(*thread)(void *) = shared_thread; |
| 142 | |
| 143 | thread_count = DEFAULT_THREAD_COUNT; |
| 144 | runtime = DEFAULT_RUNTIME; |
| 145 | |
| 146 | /* Process arguments */ |
| 147 | while ((opt = getopt(argc, argv, "t:n:i")) != -1) { |
| 148 | switch (opt) { |
| 149 | case 't': |
| 150 | runtime = atoi(optarg); |
| 151 | break; |
| 152 | case 'n': |
| 153 | thread_count = atoi(optarg); |
| 154 | break; |
| 155 | case 'i': |
| 156 | thread = independent_thread; |
| 157 | printf("using independent threads\n"); |
| 158 | break; |
| 159 | default: |
| 160 | printf("Usage: %s [-t <secs>] [-n <numthreads>] [-i]\n", argv[0]); |
| 161 | printf(" -t: time to run\n"); |
| 162 | printf(" -n: number of threads\n"); |
| 163 | printf(" -i: use independent threads\n"); |
| 164 | return -1; |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | if (thread_count > MAX_THREADS) |
| 169 | thread_count = MAX_THREADS; |
| 170 | |
| 171 | |
| 172 | setbuf(stdout, NULL); |
| 173 | |
| 174 | start = time(0); |
| 175 | strftime(buf, 255, "%a, %d %b %Y %T %z", localtime(&start)); |
| 176 | printf("%s\n", buf); |
| 177 | printf("Testing consistency with %i threads for %ld seconds: ", thread_count, runtime); |
| 178 | |
| 179 | /* spawn */ |
| 180 | for (i = 0; i < thread_count; i++) |
| 181 | pthread_create(&pth[i], 0, thread, 0); |
| 182 | |
| 183 | while (time(&now) < start + runtime) { |
| 184 | sleep(1); |
| 185 | if (done) { |
| 186 | ret = 1; |
| 187 | strftime(buf, 255, "%a, %d %b %Y %T %z", localtime(&now)); |
| 188 | printf("%s\n", buf); |
| 189 | goto out; |
| 190 | } |
| 191 | } |
| 192 | printf("[OK]\n"); |
| 193 | done = 1; |
| 194 | |
| 195 | out: |
| 196 | /* wait */ |
| 197 | for (i = 0; i < thread_count; i++) |
| 198 | pthread_join(pth[i], &tret); |
| 199 | |
| 200 | /* die */ |
| 201 | if (ret) |
| 202 | ksft_exit_fail(); |
| 203 | return ksft_exit_pass(); |
| 204 | } |