regress/sys/kern/lockf2/lockf2.c

   1 /*      $NetBSD$        */
   2
   3 /*-
   4  * Copyright (c)2008 YAMAMOTO Takashi,
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <assert.h>
  30 #include <errno.h>
  31 #include <signal.h>
  32 #include <stdlib.h>
  33 #include <unistd.h>
  34
  35 static int
  36 dolock(int fd, int op, off_t off, off_t size)
  37 {
  38         off_t result;
  39         int ret;
  40
  41         result = lseek(fd, off, SEEK_SET);
  42         if (result == -1) {
  43                 return errno;
  44         }
  45         assert(result == off);
  46         ret = lockf(fd, op, size);
  47         if (ret == -1) {
  48                 return errno;
  49         }
  50         return 0;
  51 }
  52
  53 int
  54 main(int argc, char *argv[])
  55 {
  56         int fd = STDOUT_FILENO;
  57         int error;
  58         int ret;
  59         pid_t pid;
  60
  61         error = dolock(fd, F_LOCK, 0, 1);
  62         assert(error == 0);
  63
  64         pid = fork();
  65         assert(pid != -1);
  66         if (pid == 0) {
  67                 error = dolock(fd, F_LOCK, 1, 1);
  68                 assert(error == 0);
  69                 dolock(fd, F_LOCK, 0, 1);       /* will block */
  70                 assert(0);
  71         }
  72         sleep(1);
  73
  74         error = dolock(fd, F_LOCK, 1, 1);
  75         assert(error == EDEADLK);
  76         ret = kill(pid, SIGKILL);
  77         assert(ret == 0);
  78
  79         exit(EXIT_SUCCESS);
  80 }