Attachment 248653 Details for Bug 276002 – Problem reproducer

Problem reproducer

mmap44.c (text/plain), 3.30 KB, created by Peter Holm on 2024-02-21 08:41:28 UTC

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Creator: Peter Holm

Created: 2024-02-21 08:41:28 UTC

Size: 3.30 KB

patch

obsolete

>#include <sys/mman.h>
>#include <sys/stat.h>
>
>#include <err.h>
>#include <fcntl.h>
>#include <pthread.h>
>#include <stdio.h>
>#include <stdlib.h>
>#include <string.h>
>#include <unistd.h>
>
>static off_t siz;
>static pthread_mutex_t write_mutex;
>static int fd, go;
>static char *cp;
>
>static void *
>memread(void *arg __unused)
>{
>	int i;
>	char c;
>
>	while (go == 1) {
>		i = arc4random() % siz;
>		c = cp[i];
>		if (c != 0x77) /* No unused vars here */
>			usleep(arc4random() % 400);
>	}
>	return (0);
>}
>
>static void *
>memwrite(void *arg __unused)
>{
>	int i;
>	char c;
>
>	while (go == 1) {
>		i = arc4random() % siz;
>		pthread_mutex_lock(&write_mutex);
>		c = cp[i];
>		cp[i] = 0xee;	/* This value seems to linger with NFS */
>		cp[i] = c;
>		pthread_mutex_unlock(&write_mutex);
>		usleep(arc4random() % 400);
>	}
>	return (0);
>}
>
>static void *
>wr(void *arg __unused)
>{
>	off_t pos;
>	int r, s;
>	char buf[1024];
>
>	while (go == 1) {
>		s = arc4random() % sizeof(buf) + 1;
>		pos = arc4random() % (siz - s);
>		pthread_mutex_lock(&write_mutex);
>		if (lseek(fd, pos, SEEK_SET) == -1)
>			err(1, "lseek(%d)", (int)pos);
>		if ((r = read(fd, buf, s)) != s) {
>			fprintf(stderr, "r = %d, s = %d, pos = %d\n", r, s, (int)pos);
>			err(1, "read():2");
>		}
>		if (lseek(fd, pos, SEEK_SET) == -1)
>			err(1, "lseek(%d)", (int)pos);
>		if (write(fd, buf, s) != s)
>			err(1, "write()");
>		pthread_mutex_unlock(&write_mutex);
>		usleep(arc4random() % 400);
>	}
>	return (0);
>}
>
>static void *
>s1(void *arg __unused)
>{
>
>	while (go == 1) {
>		if (fdatasync(fd) == -1)
>			err(1, "fdatasync()");
>		usleep(arc4random() % 1000);
>	}
>	return (0);
>}
>
>static void *
>s2(void *arg __unused)
>{
>
>	while (go == 1) {
>		if (fsync(fd) == -1)
>			err(1, "fdatasync()");
>		usleep(arc4random() % 1000);
>	}
>	return (0);
>}
>
>static void *
>tr(void *arg __unused)
>{
>	int i, s;
>	char buf[1024];
>
>	memset(buf, 0x5a, sizeof(buf));
>	while (go == 1) {
>		pthread_mutex_lock(&write_mutex);
>		if (lseek(fd, arc4random() % siz, SEEK_END) == -1)
>			err(1, "lseek() END");
>		s = sizeof(buf);
>		for (i = 0; i < 50; i++) {
>			if (write(fd, buf, s) != s)
>				warn("write()");
>		}
>		if (ftruncate(fd, siz) == -1)
>			err(1, "truncate()");
>		pthread_mutex_unlock(&write_mutex);
>		usleep(arc4random() % 400);
>	}
>	return (0);
>}
>
>int
>main(int argc, char *argv[])
>{
>	struct stat st;
>	pthread_t tp[6];
>	int e, i;
>
>	if (argc != 2) {
>		fprintf(stderr, "Usage: %s <file>\n", argv[0]);
>		exit(1);
>	}
>	if ((fd = open(argv[1], O_RDWR)) == -1)
>		err(1, "open(%s)", argv[1]);
>	if (fstat(fd, &st) == -1)
>		err(1, "stat(%s)", argv[1]);
>	siz = st.st_size;
>	cp = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
>	if (cp == MAP_FAILED)
>		err(1, "mmap()");
>
>	go = 1;
>	pthread_mutex_init(&write_mutex, NULL);
>	if ((e = pthread_create(&tp[0], NULL, memwrite, NULL)) != 0)
>		errc(1, e, "pthread_create");
>	if ((e = pthread_create(&tp[1], NULL, memread, NULL)) != 0)
>		errc(1, e, "pthread_create");
>	if ((e = pthread_create(&tp[2], NULL, wr, NULL)) != 0)
>		errc(1, e, "pthread_create");
>	if ((e = pthread_create(&tp[3], NULL, s1, NULL)) != 0)
>		errc(1, e, "pthread_create");
>	if ((e = pthread_create(&tp[4], NULL, s2, NULL)) != 0)
>		errc(1, e, "pthread_create");
>	if ((e = pthread_create(&tp[5], NULL, tr, NULL)) != 0)
>		errc(1, e, "pthread_create");
>
>	sleep(60);
>	go = 0;
>	for (i = 0; i < 5; i++)
>		pthread_join(tp[i], NULL);
>	if (munmap(cp, siz) == -1)
>		err(1, "munmap()");
>	close(fd);
>}

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