tests/read-vs-mmap2.c

   1 /*
   2  * Copyright (c) 1995 - 2001 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 #include <roken.h>
  49
  50 #ifdef RCSID
  51 RCSID("$Id$");
  52 #endif
  53
  54 static void
  55 generate_random_file (const char *filename, size_t sz)
  56 {
  57     int fd;
  58     char *buf;
  59     int i;
  60
  61     buf = malloc (sz);
  62     if (buf == NULL)
  63         err (1, "malloc %u", (unsigned)sz);
  64
  65     fd = open (filename, O_WRONLY | O_CREAT, 0666);
  66     if (fd < 0)
  67         err (1, "open %s", filename);
  68
  69     for (i = 0; i < sz; ++i)
  70         buf[i] = rand();
  71
  72     if (write (fd, buf, sz) != sz)
  73         err (1, "write");
  74     if (close (fd))
  75         err (1, "close");
  76     free (buf);
  77 }
  78
  79 static char *
  80 read_file (int fd, size_t sz)
  81 {
  82     char *buf;
  83     ssize_t ret;
  84
  85     buf = malloc (sz);
  86     if (buf == NULL)
  87         err (1, "malloc %u", (unsigned)sz);
  88     ret = read(fd, buf, sz);
  89     if(ret < 0)
  90         err(1, "read");
  91     if(ret != sz)
  92         errx(1, "short read %d < %u", (int)ret, (unsigned)sz);
  93     return buf;
  94 }
  95
  96 #ifndef MAP_FAILED
  97 #define MAP_FAILED ((void *)-1)
  98 #endif
  99
 100 static void *
 101 mmap_file (int fd, size_t sz)
 102 {
 103     void *ret;
 104
 105     ret = mmap (0, sz, PROT_READ, MAP_SHARED, fd, 0);
 106     if (ret == (void *)MAP_FAILED)
 107         err (1, "mmap");
 108     return ret;
 109 }
 110
 111 int
 112 main (int argc, char **argv)
 113 {
 114     const char *file = "foo";
 115     const size_t sz  = 16384;
 116     char *malloc_buf;
 117     void *mmap_buf;
 118     int fd;
 119
 120     setprogname (argv[0]);
 121
 122     srand (time(NULL));
 123
 124     generate_random_file (file, sz);
 125
 126     fd = open (file, O_RDONLY, 0);
 127     if (fd < 0)
 128         err (1, "open %s", file);
 129
 130     malloc_buf = read_file (fd, sz);
 131     mmap_buf   = mmap_file (fd, sz);
 132     close (fd);
 133     unlink (file);
 134     if (memcmp (malloc_buf, mmap_buf, sz) != 0)
 135         return 1;
 136     return 0;
 137 }