lib/libc/gen/seekdir.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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  * $FreeBSD: src/lib/libc/gen/seekdir.c,v 1.2.8.1 2001/03/05 09:52:13 obrien Exp $
  34  * $DragonFly: src/lib/libc/gen/seekdir.c,v 1.6 2005/11/19 22:32:53 swildner Exp $
  35  *
  36  * @(#)seekdir.c        8.1 (Berkeley) 6/4/93
  37  */
  38
  39 #include "namespace.h"
  40 #include <sys/param.h>
  41 #include <dirent.h>
  42 #include <pthread.h>
  43 #include "un-namespace.h"
  44
  45 #include "libc_private.h"
  46
  47 /*
  48  * Seek to an entry in a directory.
  49  * _seekdir is in telldir.c so that it can share opaque data structures.
  50  */
  51 void
  52 seekdir(DIR *dirp, long loc)
  53 {
  54         if (__isthreaded)
  55                 _pthread_mutex_lock((pthread_mutex_t *)&dirp->dd_lock);
  56         _seekdir(dirp, loc);
  57         if (__isthreaded)
  58                 _pthread_mutex_unlock((pthread_mutex_t *)&dirp->dd_lock);
  59 }