8a272653d9
Discussed with: kib
215 lines
4.7 KiB
Bash
Executable File
215 lines
4.7 KiB
Bash
Executable File
#!/bin/sh
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#
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# Copyright (c) 2017 Dell EMC Isilon
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# All rights reserved.
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions
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# are met:
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# 1. Redistributions of source code must retain the above copyright
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# notice, this list of conditions and the following disclaimer.
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# 2. Redistributions in binary form must reproduce the above copyright
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# notice, this list of conditions and the following disclaimer in the
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# documentation and/or other materials provided with the distribution.
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#
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# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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# SUCH DAMAGE.
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#
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# mkfifo(2), select(2) with tmpfs(5) scenario.
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. ../default.cfg
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[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
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dir=/tmp
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odir=`pwd`
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cd $dir
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sed '1,/^EOF/d' < $odir/$0 > $dir/mkfifo5.c
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mycc -o mkfifo5 -Wall -Wextra -O0 -g mkfifo5.c || exit 1
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rm -f mkfifo5.c
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cd $odir
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mount | grep -q "on $mntpoint " && umount -f $mntpoint
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mount -o size=1g -t tmpfs tmpfs $mntpoint
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fifo=$mntpoint/fifo.file
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cd $mntpoint
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/tmp/mkfifo5 $fifo
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s=$?
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cd $odir
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while mount | grep "on $mntpoint " | grep -q tmpfs; do
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umount $mntpoint || sleep 1
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done
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rm -rf /tmp/mkfifo5
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exit $s
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EOF
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#include <sys/param.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <sys/wait.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <time.h>
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#include <unistd.h>
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static char *path;
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#define PARALLEL 1
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static void
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reader(void)
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{
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fd_set rset;
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struct timeval timeout;
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int fd, n, r;
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char ch;
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do {
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if((fd = open(path, O_RDONLY)) == -1)
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if (errno != EINTR)
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err(1, "open(%s, O_RDONLY)",
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path);
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if (fd == -1)
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warn("open(%s) ro", path);
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} while (fd == -1);
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/* Read one character */
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FD_ZERO(&rset);
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FD_SET(fd, &rset);
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if ((n = select(fd + 1, &rset, NULL, NULL, NULL)) < 0)
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if (errno != EINTR)
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err(1, "select()");
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if (n == 1 && FD_ISSET(fd, &rset)) {
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r = read(fd, &ch, 1);
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if (r == -1)
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err(1, "read");
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if (r == 0)
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fprintf(stderr, "read(1): EOF\n");
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}
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/* timeout */
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ch = 'z';
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FD_ZERO(&rset);
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FD_SET(fd, &rset);
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timeout.tv_sec = 1;
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timeout.tv_usec = 0;
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if ((n = select(fd + 1, &rset, NULL, NULL, &timeout)) < 0)
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if (errno != EINTR)
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err(1, "select()");
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if (n != 1)
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fprintf(stderr, "FAIL Expected n == 0, got %d\n", n);
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if (n == 1 && FD_ISSET(fd, &rset)) {
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r = read(fd, &ch, 1);
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if (r == -1)
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err(1, "read");
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if (r == 0)
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fprintf(stderr, "read(2): EOF\n");
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}
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/* timeout */
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ch = 'z';
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FD_ZERO(&rset);
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FD_SET(fd, &rset);
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timeout.tv_sec = 1;
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timeout.tv_usec = 0;
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if ((n = select(fd + 1, &rset, NULL, NULL, &timeout)) < 0)
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if (errno != EINTR)
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err(1, "select()");
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if (n != 1)
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fprintf(stderr, "FAIL Expected n == 0, got %d\n", n);
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if (n == 1 && FD_ISSET(fd, &rset)) {
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r = read(fd, &ch, 1);
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if (r == -1)
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err(1, "read");
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if (r != 0)
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fprintf(stderr, "read(3): %c\n", ch);
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}
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if (close(fd) == -1)
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err(1, "close() in child");
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_exit(n == 1 ? 0 : 1);
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}
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static void
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writer(void)
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{
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int fd;
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do {
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if ((fd = open(path, O_WRONLY)) == -1)
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if (errno != EINTR)
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err(1, "open(%s, O_WRONLY)",
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path);
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if (fd == -1)
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warn("open(%s) wr", path);
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} while (fd == -1);
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if (write(fd, "a", 1) != 1)
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err(1, "write one");
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if (write(fd, "b", 1) != 1)
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err(1, "write one");
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if (close(fd) == -1)
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warn("close() in parent");
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}
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static void
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test(void)
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{
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pid_t pid;
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int status;
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if ((pid = fork()) == 0)
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reader();
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writer();
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if (waitpid(pid, &status, 0) != pid)
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err(1, "waitpid(%d)", pid);
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_exit(status != 0);
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}
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int
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main(int argc __unused, char *argv[])
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{
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int e, i, pids[PARALLEL], status;
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if (argc != 2) {
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fprintf(stderr, "Usage: %s <fifo file>\n", argv[0]);
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exit(1);
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}
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path = argv[1];
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e = 0;
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unlink(path);
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if (mkfifo(path, 0640) == -1)
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err(1, "mkfifo(%s)", path);
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for (i = 0; i < PARALLEL; i++) {
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if ((pids[i] = fork()) == 0)
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test();
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}
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for (i = 0; i < PARALLEL; i++) {
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if (waitpid(pids[i], &status, 0) == -1)
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err(1, "waitpid(%d)", pids[i]);
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e += status == 0 ? 0 : 1;
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}
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return (e);
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}
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