Attachment 871886 Details for Bug 1218801

reproducer

mutex_pi.c (text/plain), 1.74 KB, created by Jiri Slaby on 2024-01-16 07:58:14 UTC

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Creator: Jiri Slaby

Created: 2024-01-16 07:58:14 UTC

Size: 1.74 KB

patch

obsolete

>#include <errno.h>
>#include <pthread.h>
>#include <stdio.h>
>#include <stdlib.h>
>#include <unistd.h>
>
>#include <sys/mman.h>
>#include <sys/time.h>
>#include <sys/wait.h>
>
>#define MAX_WAIT_USEC (1000*1000)
>#define CHILDREN 16
>#define MAX_ITER 200
>
>#define NS_PER_S 1000000000
>
>static pthread_mutex_t *proc_lock;
>
>static void child()
>{
>	for (unsigned int i = 0; i < MAX_ITER; i++) {
>		unsigned int wait_usec = 0;
>		struct timespec abstime;
>		int rv;
>
>		while (1) {
>			clock_gettime(CLOCK_REALTIME, &abstime);
>
>			abstime.tv_nsec += 1000;
>			if (abstime.tv_nsec >= NS_PER_S) {
>				abstime.tv_sec++;
>				abstime.tv_nsec -= NS_PER_S;
>			}
>
>			rv = pthread_mutex_timedlock(proc_lock, &abstime);
>			if (rv == 0)
>				break;
>			if (rv == EOWNERDEAD) {
>				pthread_mutex_consistent(proc_lock);
>				break;
>			}
>			if (rv != ETIMEDOUT) {
>				fprintf(stderr, "BADx rv=%d\n", rv);
>				abort();
>			}
>
>			if (++wait_usec >= MAX_WAIT_USEC) {
>				fprintf(stderr, "TIME OUT\n");
>				abort();
>			}
>		}
>
>		usleep(1);
>		if (pthread_mutex_unlock(proc_lock))
>			abort();
>	}
>
>	exit(0);
>}
>
>int main(void)
>{
>	proc_lock = mmap(NULL, sizeof(*proc_lock),
>			 PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED,
>			 -1, 0);
>
>	pthread_mutexattr_t mattr;
>
>	pthread_mutexattr_init(&mattr);
>	pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
>	pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);
>	pthread_mutexattr_setprotocol(&mattr, PTHREAD_PRIO_INHERIT);
>
>	pthread_mutex_init(proc_lock, &mattr);
>
>	pthread_mutexattr_destroy(&mattr);
>
>	for (unsigned a = 0; a < CHILDREN; a++)
>		if (!fork())
>			child();
>
>	for (unsigned a = 0; a < CHILDREN; a++) {
>		int s;
>		pid_t ch = wait(&s);
>		if (WIFSIGNALED(s))
>			fprintf(stderr, "child %d failed\n", ch);
>	}
>
>	pthread_mutex_destroy(proc_lock);
>
>	return 0;
>}

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Attachments on bug 1218801: 871875 | 871886