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Diffstat (limited to 'tools/testing/selftests/timers/threadtest.c')
| -rw-r--r-- | tools/testing/selftests/timers/threadtest.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/tools/testing/selftests/timers/threadtest.c b/tools/testing/selftests/timers/threadtest.c new file mode 100644 index 0000000000..80aed4bf06 --- /dev/null +++ b/tools/testing/selftests/timers/threadtest.c @@ -0,0 +1,193 @@ +/* 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> +#include "../kselftest.h" + +/* 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 synchronization 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; +} + +#define DEFAULT_THREAD_COUNT 8 +#define DEFAULT_RUNTIME 30 + +int main(int argc, char **argv) +{ + int thread_count, i; + time_t start, now, runtime; + char buf[255]; + pthread_t pth[MAX_THREADS]; + int opt; + void *tret; + int ret = 0; + void *(*thread)(void *) = shared_thread; + + thread_count = DEFAULT_THREAD_COUNT; + runtime = DEFAULT_RUNTIME; + + /* 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); + fflush(stdout); + + /* 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(); +} |