posix/tst-preadwrite-common.c

   1 /* Common definitions for pread and pwrite.
   2    Copyright (C) 2016 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <error.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23
  24 static void do_prepare (void);
  25 #define PREPARE(argc, argv)     do_prepare ()
  26 static int do_test (void);
  27 #define TEST_FUNCTION           do_test ()
  28
  29 /* We might need a bit longer timeout.  */
  30 #define TIMEOUT 20 /* sec */
  31
  32 /* This defines the `main' function and some more.  */
  33 #include <test-skeleton.c>
  34
  35 /* These are for the temporary file we generate.  */
  36 static char *name;
  37 static int fd;
  38
  39 static void
  40 do_prepare (void)
  41 {
  42   fd = create_temp_file ("tst-preadwrite.", &name);
  43   if (fd == -1)
  44     error (EXIT_FAILURE, errno, "cannot create temporary file");
  45 }
  46
  47
  48 static ssize_t
  49 do_test_with_offset (off_t offset)
  50 {
  51   char buf[1000];
  52   char res[1000];
  53   int i;
  54   ssize_t ret;
  55
  56   memset (buf, '\0', sizeof (buf));
  57   memset (res, '\xff', sizeof (res));
  58
  59   if (write (fd, buf, sizeof (buf)) != sizeof (buf))
  60     error (EXIT_FAILURE, errno, "during write");
  61
  62   for (i = 100; i < 200; ++i)
  63     buf[i] = i;
  64   ret = pwrite (fd, buf + 100, 100, offset + 100);
  65   if (ret == -1)
  66     error (EXIT_FAILURE, errno, "during pwrite");
  67
  68   for (i = 450; i < 600; ++i)
  69     buf[i] = i;
  70   ret = pwrite (fd, buf + 450, 150, offset + 450);
  71   if (ret == -1)
  72     error (EXIT_FAILURE, errno, "during pwrite");
  73
  74   ret = pread (fd, res, sizeof (buf) - 50, offset + 50);
  75   if (ret == -1)
  76     error (EXIT_FAILURE, errno, "during pread");
  77
  78   if (memcmp (buf + 50, res, ret) != 0)
  79     {
  80       printf ("error: read of pread != write of pwrite\n");
  81       return -1;
  82     }
  83
  84   return ret;
  85 }