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/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000 The Apache Software Foundation. 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.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR
* ITS 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
/*
* USAGE
*
* Start one process, no args, and place it into the background. Start a
* second process with the "-r" switch to attempt a read on the file
* created by the first process.
*
* $ ./testflock &
* ...messages...
* $ ./testflock -r
* ...messages...
*
* The first process will sleep for 30 seconds while holding a lock. The
* second process will attempt to grab it (non-blocking) and fail. It
* will then grab it with a blocking scheme. When the first process' 30
* seconds are up, it will exit (thus releasing its lock). The second
* process will acquire the lock, then exit.
*/
#include "apr_pools.h"
#include "apr_file_io.h"
#include "apr_time.h"
#include "apr_general.h"
#include "apr_getopt.h"
#include "apr_strings.h"
#include <stdlib.h>
#include <stdio.h>
#define TESTFILE "testfile.tmp"
static apr_pool_t *pool = NULL;
static void errmsg(const char *msg)
{
if (pool != NULL)
apr_destroy_pool(pool);
fprintf(stderr, msg);
exit(1);
}
static void do_read(void)
{
apr_file_t *file;
apr_status_t status;
if (apr_open(&file, TESTFILE, APR_WRITE,
APR_OS_DEFAULT, pool) != APR_SUCCESS)
errmsg("Could not open test file.\n");
printf("Test file opened.\n");
status = apr_lock_file(file, APR_FLOCK_EXCLUSIVE | APR_FLOCK_NONBLOCK);
if (!APR_STATUS_IS_EAGAIN(status)) {
char msg[200];
errmsg(apr_psprintf(pool, "Expected EAGAIN. Got %d: %s.\n",
status, apr_strerror(status, msg, sizeof(msg))));
}
printf("First attempt: we were properly locked out.\nWaiting for lock...");
fflush(stdout);
if (apr_lock_file(file, APR_FLOCK_EXCLUSIVE) != APR_SUCCESS)
errmsg("Could not establish lock on test file.");
printf(" got it.\n");
(void) apr_close(file);
printf("Exiting.\n");
}
static void do_write(void)
{
apr_file_t *file;
if (apr_open(&file, TESTFILE, APR_WRITE|APR_CREATE, APR_OS_DEFAULT,
pool) != APR_SUCCESS)
errmsg("Could not create file.\n");
printf("Test file created.\n");
if (apr_lock_file(file, APR_FLOCK_EXCLUSIVE) != APR_SUCCESS)
errmsg("Could not lock the file.\n");
printf("Lock created.\nSleeping...");
fflush(stdout);
apr_sleep(30000000); /* 30 seconds */
(void) apr_close(file);
printf(" done.\nExiting.\n");
}
static void closeapr(void)
{
apr_terminate();
}
int main(int argc, const char * const *argv)
{
int reader = 0;
apr_status_t status;
char optchar;
const char *optarg;
apr_getopt_t *opt;
if (apr_initialize() != APR_SUCCESS)
errmsg("Could not initialize APR.\n");
atexit(closeapr);
if (apr_create_pool(&pool, NULL) != APR_SUCCESS)
errmsg("Could not create global pool.\n");
if (apr_initopt(&opt, pool, argc, argv) != APR_SUCCESS)
errmsg("Could not parse options.\n");
while ((status = apr_getopt(opt, "r", &optchar, &optarg)) == APR_SUCCESS) {
if (optchar == 'r')
++reader;
}
if (reader)
do_read();
else
do_write();
return 0;
}
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