tests/mmap-and-fork.c

   1 /*
   2  * Copyright (c) 2003 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 <sys/wait.h>
  42 #include <fcntl.h>
  43 #include <time.h>
  44 #include <unistd.h>
  45 #include <string.h>
  46 #include <sys/mman.h>
  47 #include <sys/stat.h>
  48 #include <err.h>
  49 #include <roken.h>
  50
  51 #ifndef MAP_FAILED
  52 #define MAP_FAILED ((void *)-1)
  53 #endif
  54
  55 #ifdef RCSID
  56 RCSID("$Id$");
  57 #endif
  58
  59 static void
  60 doit (const char *filename, int close_before_p, int unmapp)
  61 {
  62     pid_t pid;
  63     int fd;
  64     size_t sz = getpagesize ();
  65     void *v;
  66
  67     fd = open (filename, O_RDWR | O_CREAT, 0600);
  68     if (fd < 0)
  69         err (1, "open %s", filename);
  70     if (ftruncate (fd, sz) < 0)
  71         err (1, "ftruncate %s", filename);
  72     v = mmap (NULL, sz, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  73     if (v == (void *)MAP_FAILED)
  74         err (1, "mmap %s", filename);
  75
  76     memset (v, 'z', sz);
  77
  78     if (close_before_p)
  79         close(fd);
  80
  81     pid = fork();
  82     if (pid < 0)
  83         errx (1, "fork failed");
  84
  85     if (pid == 0) {
  86         memset (v, 'x', sz);
  87         _exit(0);
  88     } else {
  89         int stat;
  90         if (waitpid (pid, &stat, 0) < 0)
  91             errx(1, "waitpid");
  92     }
  93     memset (v, 'y', sz);
  94
  95     if (!close_before_p)
  96         close(fd);
  97
  98     if (unmapp)
  99         munmap(v, sz);
 100
 101 }
 102
 103 int
 104 main (int argc, char **argv)
 105 {
 106     setprogname(argv[0]);
 107
 108     doit ("foo1", 0, 0);
 109     doit ("foo2", 1, 0);
 110     doit ("foo3", 0, 1);
 111     doit ("foo4", 1, 1);
 112
 113     doit ("foo1", 0, 0);
 114     doit ("foo2", 1, 0);
 115     doit ("foo3", 0, 1);
 116     doit ("foo4", 1, 1);
 117
 118     unlink("foo1");
 119     unlink("foo2");
 120     unlink("foo3");
 121     unlink("foo4");
 122
 123     return 0;
 124 }