Date: Mon, 7 Jul 2014 06:37:14 +0000 (UTC) From: Peter Holm <pho@FreeBSD.org> To: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: svn commit: r268358 - user/pho/stress2/misc Message-ID: <201407070637.s676bEnA085926@svn.freebsd.org>
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Author: pho Date: Mon Jul 7 06:37:14 2014 New Revision: 268358 URL: http://svnweb.freebsd.org/changeset/base/268358 Log: Added fcntl(2) locking scenario. Sponsored by: EMC / Isilon storage division Added: user/pho/stress2/misc/fcntl.sh (contents, props changed) Added: user/pho/stress2/misc/fcntl.sh ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ user/pho/stress2/misc/fcntl.sh Mon Jul 7 06:37:14 2014 (r268358) @@ -0,0 +1,223 @@ +#!/bin/sh + +# +# Copyright (c) 2014 EMC Corp. +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions +# are met: +# 1. Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# 2. Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# +# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +# SUCH DAMAGE. +# +# $FreeBSD$ +# + +# fcntl(2) locking scenario. No problems seen. + +here=`pwd` +cd /tmp +sed '1,/^EOF/d' < $here/$0 > fcntl.c +cc -o fcntl -Wall -Wextra -O0 -g fcntl.c || exit 1 +rm -f fcntl.c + +/tmp/fcntl +status=$? + +rm -f /tmp/fcntl +exit $status +EOF +#include <sys/types.h> +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/wait.h> +#include <unistd.h> + +#define PARALLEL 16 +#define N 4096 + +static volatile sig_atomic_t completed; +const char name[] = "work"; +int fd; + +static void +handler(int s __unused) +{ + completed++; +} + +void +add(int n, int increment) +{ + struct flock fl; + off_t pos; + long val, oval; + int r; + + pos = n * sizeof(val); + memset(&fl, 0, sizeof(fl)); + fl.l_start = pos; + fl.l_len = sizeof(val); + fl.l_type = F_WRLCK; + fl.l_whence = SEEK_SET; + + while (fcntl(fd, F_SETLK, &fl) < 0) { + if (errno != EAGAIN) + err(1, "F_SETLK (child)"); + usleep(100); + } + + if (lseek(fd, pos, SEEK_SET) == -1) + err(1, "lseek"); + oval = 999999; + while ((r = read(fd, &val, sizeof(val)) != sizeof(val))) { + if (r == -1 && errno != EAGAIN) + err(1, "read"); + if (lseek(fd, pos, SEEK_SET) == -1) + err(1, "lseek"); + } + oval = val; + val = val + increment; +#if defined(DEBUG) + fprintf(stderr, "add(%d, %d) @ pos %ld: %ld = %ld + %d\n", + n, increment, (long)pos, val, oval, increment); +#endif + if (lseek(fd, pos, SEEK_SET) == -1) + err(1, "lseek"); + while ((r = write(fd, &val, sizeof(val)) != sizeof(val))) { + if (r == -1 && errno != EAGAIN) + err(1, "write"); + if (lseek(fd, pos, SEEK_SET) == -1) + err(1, "lseek"); + } + + fl.l_type = F_UNLCK; + if (fcntl(fd, F_SETLK, &fl) < 0) + err(1, "F_UNLCK"); + +} + +void +up(void) +{ + int flags, i; + + /* Need to re-open after a fork() */ + close(fd); + if ((fd = open(name, O_RDWR)) == -1) + err(1, "open(%s)", name); + if ((flags = fcntl(fd, F_GETFL)) == -1) + err(1, "fcntl(%d, T_GETFL)", fd); + flags |= O_NONBLOCK; + if ((flags = fcntl(fd, F_SETFL, flags)) == -1) + err(1, "fcntl(%d, T_SETFL, %d)", fd, flags); + + for (i = 0; i < N; i++) + add(i, 1); + + kill(getppid(), SIGHUP); + while (access("work", R_OK) == 0) + usleep(100); + + _exit(0); +} + +void +down(void) +{ + int flags, i; + + close(fd); + if ((fd = open(name, O_RDWR)) == -1) + err(1, "open(%s)", name); + if ((flags = fcntl(fd, F_GETFL)) == -1) + err(1, "fcntl(%d, T_GETFL)", fd); + flags |= O_NONBLOCK; + if ((flags = fcntl(fd, F_SETFL, flags)) == -1) + err(1, "fcntl(%d, T_SETFL, %d)", fd, flags); + + for (i = 0; i < N; i++) + add(i, -1); + + kill(getppid(), SIGHUP); + while (access("work", R_OK) == 0) + usleep(100); + + _exit(0); +} + +int +main(void) +{ + int flags, i; + long val, sum; + off_t len; + + signal(SIGHUP, handler); + if ((fd = open(name, O_RDWR | O_CREAT | O_TRUNC, 0640)) == -1) + err(1, "open(%s)", name); + len = N * sizeof(val); + if (ftruncate(fd, len) == -1) + err(1, "ftruncate"); + + if ((flags = fcntl(fd, F_GETFL)) == -1) + err(1, "fcntl(%d, T_GETFL)", fd); + flags |= O_NONBLOCK; + if ((flags = fcntl(fd, F_SETFL, flags)) == -1) + err(1, "fcntl(%d, T_SETFL, %d)", fd, flags); + + for (i = 0; i < PARALLEL; i++) { + if (fork() == 0) + up(); + } + for (i = 0; i < PARALLEL; i++) { + if (fork() == 0) + down(); + } + + while (completed != PARALLEL * 2) + usleep(200); + + if (lseek(fd, 0, SEEK_SET) == -1) + err(1, "lseek"); + sum = 0; + for (i = 0; i < N; i++) { + if (read(fd, &val, sizeof(val)) != sizeof(val)) + err(1, "Final read"); + if (val != 0) + fprintf(stderr, "index %d: %ld\n", i, val); + sum += val; + } + if (sum != 0) + fprintf(stderr, "FAIL\n"); + unlink(name); + + for (i = 0; i < PARALLEL; i++) { + wait(NULL); + wait(NULL); + } + + close(fd); + + return (sum != 0); +}
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