src/tests/mmap-shared-write.c

   1 /*
   2  * Copyright (c) 2000 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 #endif
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <sys/types.h>
  41 #include <fcntl.h>
  42 #include <time.h>
  43 #include <unistd.h>
  44 #include <string.h>
  45 #include <sys/mman.h>
  46 #include <sys/stat.h>
  47 #include <err.h>
  48
  49 #ifndef MAP_FAILED
  50 #define MAP_FAILED ((void *)-1)
  51 #endif
  52
  53 static int
  54 doit(const char *filename)
  55 {
  56     int fd;
  57     size_t sz = getpagesize();
  58     void *v;
  59
  60     fd = open(filename, O_RDWR | O_CREAT, 0600);
  61     if (fd < 0)
  62         err(1, "open %s", filename);
  63     if (ftruncate(fd, sz) < 0)
  64         err(1, "ftruncate %s", filename);
  65     v = mmap(NULL, sz, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  66     if (v == (void *)MAP_FAILED)
  67         err(1, "mmap %s", filename);
  68
  69     memset(v, 'z', sz);
  70
  71     msync(v, sz, MS_SYNC);
  72
  73     if (close(fd) < 0)
  74         err(1, "close %s", filename);
  75     return 0;
  76 }
  77
  78 static void
  79 usage(void)
  80 {
  81     errx(1, "usage: [filename]");
  82 }
  83
  84 int
  85 main(int argc, char **argv)
  86 {
  87     const char *filename = "foo";
  88
  89
  90     if (argc != 1 && argc != 2)
  91         usage();
  92
  93     if (argc == 2)
  94         filename = argv[1];
  95
  96     return doit(filename);
  97 }