Attachment 312402 Details for Bug 456282 – reproducer - lock file in one thread and close in another

reproducer - lock file in one thread and close in another

locker.c (text/plain), 1.25 KB, created by Bryn M. Reeves on 2008-07-22 22:36:03 UTC

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Creator: Bryn M. Reeves

Created: 2008-07-22 22:36:03 UTC

Size: 1.25 KB

patch

obsolete

>#include <unistd.h>
>#include <stdlib.h>
>#include <stdio.h>
>#include <sys/types.h>
>#include <sys/stat.h>
>#include <sys/syscall.h>
>#include <sched.h>
>#include <linux/unistd.h>
>#include <fcntl.h>
>#include <pthread.h>
>
>/* pid_t gettid(void) */
>_syscall0(pid_t,gettid);
>
>volatile int fd = -1;
>
>/**
> * arg - unused
> */
>void *do_lock(void *arg)
>{
>	struct flock fl;
>
>	fprintf(stderr, "pid %d thread %d in do_lock\n", getpid(), gettid());
>
>	fl.l_type = F_WRLCK;
>	fl.l_whence = SEEK_SET;
>	fl.l_start = 0; /* may as well lock it all */
>	fl.l_len = 0;
>
>	fprintf(stderr, "pid %d thread %d  locking\n", getpid(), gettid());
>	if(fcntl(fd, F_SETLKW, &fl) == -1) {
>		perror("fcntl");
>		exit(1);
>	}
>	fprintf(stderr, "pid %d thread %d  LOCKED\n", getpid(), gettid());
>	return NULL;
>}
>
>/**
> * Attempt to lock a file in one thread while terminating
> * the process from another.
> *
> * argv[1] - file system path to lock
> */
>int main(int argc, char **argv)
>{
>	pthread_t locker;
>
>	if (argc < 2) {
>		fprintf(stderr, "usage:\n%s <path>\n", argv[0]);
>		exit(1);
>	}
>
>	fd = open(argv[1], O_RDWR);
>	if (fd < 0) {
>		perror("open");
>		exit(1);
>	}
>
>	fprintf(stderr, "pid %d main launching thread\n", getpid());
>	pthread_create(&locker, NULL, do_lock, argv[1]);
>
>	sched_yield();
>	close(fd);
>	pause();
>	return 0;
>}

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Attachments on bug 456282: 312392 | 312402 | 314636 | 325729 | 326611