105 lines
2.3 KiB
C
105 lines
2.3 KiB
C
/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License (the "License").
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* You may not use this file except in compliance with the License.
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*
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* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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* or http://www.opensolaris.org/os/licensing.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information: Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*/
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/*
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* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
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* Use is subject to license terms.
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*/
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#include <unistd.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mman.h>
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#include <pthread.h>
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/*
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* --------------------------------------------------------------------
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* Bug Id: 5032643
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*
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* Simply writing to a file and mmaping that file at the same time can
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* result in deadlock. Nothing perverse like writing from the file's
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* own mapping is required.
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* --------------------------------------------------------------------
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*/
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static void *
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mapper(void *fdp)
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{
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void *addr;
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int fd = *(int *)fdp;
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if ((addr =
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mmap(0, 8192, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
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perror("mmap");
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exit(1);
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}
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for (;;) {
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if (mmap(addr, 8192, PROT_READ,
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MAP_SHARED|MAP_FIXED, fd, 0) == MAP_FAILED) {
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perror("mmap");
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exit(1);
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}
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}
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/* NOTREACHED */
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return ((void *)1);
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}
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int
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main(int argc, char **argv)
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{
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int fd;
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char buf[1024];
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pthread_t tid;
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memset(buf, 'a', sizeof (buf));
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if (argc != 2) {
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(void) printf("usage: %s <file name>\n", argv[0]);
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exit(1);
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}
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if ((fd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0666)) == -1) {
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perror("open");
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exit(1);
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}
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(void) pthread_setconcurrency(2);
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if (pthread_create(&tid, NULL, mapper, &fd) != 0) {
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perror("pthread_create");
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close(fd);
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exit(1);
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}
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for (;;) {
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if (write(fd, buf, sizeof (buf)) == -1) {
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perror("write");
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close(fd);
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exit(1);
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}
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}
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close(fd);
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/* NOTREACHED */
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return (0);
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}
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