usr/src/cmd/dtrace/test/tst/common/io/tst.fds.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <assert.h>
  30 #include <setjmp.h>
  31 #include <signal.h>
  32 #include <unistd.h>
  33 #include <stdlib.h>
  34 #include <stdio.h>
  35 #include <fcntl.h>
  36
  37 static sigjmp_buf env;
  38
  39 static void
  40 interrupt(int sig)
  41 {
  42         siglongjmp(env, sig);
  43 }
  44
  45 int
  46 main(int argc, char *argv[])
  47 {
  48         const char *file = "/dev/null";
  49         int i, n, fds[10];
  50         struct sigaction act;
  51
  52         if (argc > 1) {
  53                 (void) fprintf(stderr, "Usage: %s\n", argv[0]);
  54                 return (EXIT_FAILURE);
  55         }
  56
  57         act.sa_handler = interrupt;
  58         act.sa_flags = 0;
  59
  60         (void) sigemptyset(&act.sa_mask);
  61         (void) sigaction(SIGUSR1, &act, NULL);
  62
  63         closefrom(0);
  64         n = 0;
  65
  66         /*
  67          * With all of our file descriptors closed, wait here spinning in bogus
  68          * ioctl() calls until DTrace hits us with a SIGUSR1 to start the test.
  69          */
  70         if (sigsetjmp(env, 1) == 0) {
  71                 for (;;)
  72                         (void) ioctl(-1, -1, NULL);
  73         }
  74
  75         /*
  76          * To test the fds[] array, we open /dev/null (a file with reliable
  77          * pathname and properties) using various flags and seek offsets.
  78          */
  79         fds[n++] = open(file, O_RDONLY);
  80         fds[n++] = open(file, O_WRONLY);
  81         fds[n++] = open(file, O_RDWR);
  82
  83         fds[n++] = open(file, O_RDWR | O_APPEND | O_CREAT | O_DSYNC |
  84             O_LARGEFILE | O_NOCTTY | O_NONBLOCK | O_NDELAY | O_RSYNC |
  85             O_SYNC | O_TRUNC | O_XATTR);
  86
  87         fds[n++] = open(file, O_RDWR);
  88         (void) lseek(fds[n - 1], 123, SEEK_SET);
  89
  90         /*
  91          * Once we have all the file descriptors in the state we want to test,
  92          * issue a bogus ioctl() on each fd with cmd -1 and arg NULL to whack
  93          * our DTrace script into recording the content of the fds[] array.
  94          */
  95         for (i = 0; i < n; i++)
  96                 (void) ioctl(fds[i], -1, NULL);
  97
  98         assert(n <= sizeof (fds) / sizeof (fds[0]));
  99         exit(0);
 100 }