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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright (c) 2013 by Delphix. All rights reserved.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <pthread.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
/*
* The size of the output file, "go.out", should be 80*8192*2 = 1310720
*
* $ cd /tmp; go; ls -l go.out
* done.
* -rwxr-xr-x 1 jdm staff 1310720 Apr 13 19:45 go.out
* $ cd /zfs; go; ls -l go.out
* done.
* -rwxr-xr-x 1 jdm staff 663552 Apr 13 19:45 go.out
*
* The file on zfs is short as it does not appear that zfs is making the
* implicit seek to EOF and the actual write atomic. From the SUSv3
* interface spec, behavior is undefined if concurrent writes are performed
* from multi-processes to a single file. So I don't know if this is a
* standards violation, but I cannot find any such disclaimers in our
* man pages. This issue came up at a customer site in another context, and
* the suggestion was to open the file with O_APPEND, but that wouldn't
* help with zfs(see 4977529). Also see bug# 5031301.
*/
static int outfd = 0;
static void *
go(void *data)
{
int ret, i = 0, n = *(int *)data;
char buf[8192] = {0};
(void) memset(buf, n, sizeof (buf));
for (i = 0; i < 80; i++) {
ret = write(outfd, buf, sizeof (buf));
if (ret != sizeof (buf))
perror("write");
}
return (NULL);
}
static void
usage(void)
{
(void) fprintf(stderr,
"usage: zfs_threadsappend <file name>\n");
exit(1);
}
int
main(int argc, char **argv)
{
pthread_t tid;
int ret = 0;
long ncpus = 0;
int i;
if (argc != 2) {
usage();
}
ncpus = sysconf(_SC_NPROCESSORS_ONLN);
if (ncpus < 0) {
(void) fprintf(stderr,
"Invalid return from sysconf(_SC_NPROCESSORS_ONLN)"
" : errno (decimal)=%d\n", errno);
exit(1);
}
if (ncpus < 2) {
(void) fprintf(stderr,
"Must execute this binary on a multi-processor system\n");
exit(1);
}
outfd = open(argv[optind++], O_RDWR|O_CREAT|O_APPEND|O_TRUNC, 0777);
if (outfd == -1) {
(void) fprintf(stderr,
"zfs_threadsappend: "
"open(%s, O_RDWR|O_CREAT|O_APPEND|O_TRUNC, 0777)"
" failed\n", argv[optind]);
perror("open");
exit(1);
}
for (i = 0; i < 2; i++) {
ret = pthread_create(&tid, NULL, go, (void *)&i);
if (ret != 0) {
(void) fprintf(stderr,
"zfs_threadsappend: thr_create(#%d) "
"failed error=%d\n", i+1, ret);
exit(1);
}
}
while (pthread_join(tid, NULL) == 0)
continue;
return (0);
}
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