2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)telldir.c 8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
36 #include "namespace.h"
37 #include <sys/param.h>
38 #include <sys/queue.h>
43 #include "un-namespace.h"
45 #include "libc_private.h"
49 * The option SINGLEUSE may be defined to say that a telldir
50 * cookie may be used only once before it is freed. This option
51 * is used to avoid having memory usage grow without bound.
56 * return a pointer into a directory
64 if ((lp = (struct ddloc *)malloc(sizeof(struct ddloc))) == NULL)
67 _pthread_mutex_lock(&dirp->dd_lock);
68 lp->loc_index = dirp->dd_td->td_loccnt++;
69 lp->loc_seek = dirp->dd_seek;
70 lp->loc_loc = dirp->dd_loc;
71 LIST_INSERT_HEAD(&dirp->dd_td->td_locq, lp, loc_lqe);
73 _pthread_mutex_unlock(&dirp->dd_lock);
74 return (lp->loc_index);
78 * seek to an entry in a directory.
79 * Only values returned by "telldir" should be passed to seekdir.
89 LIST_FOREACH(lp, &dirp->dd_td->td_locq, loc_lqe) {
90 if (lp->loc_index == loc)
95 if (lp->loc_loc == dirp->dd_loc && lp->loc_seek == dirp->dd_seek)
97 (void) lseek(dirp->dd_fd, (off_t)lp->loc_seek, SEEK_SET);
98 dirp->dd_seek = lp->loc_seek;
100 while (dirp->dd_loc < lp->loc_loc) {
101 dp = _readdir_unlocked(dirp, 0);
107 LIST_REMOVE(lp, loc_lqe);
113 * Reclaim memory for telldir cookies which weren't used.
116 _reclaim_telldir(dirp)
120 struct ddloc *templp;
122 lp = LIST_FIRST(&dirp->dd_td->td_locq);
125 lp = LIST_NEXT(lp, loc_lqe);
128 LIST_INIT(&dirp->dd_td->td_locq);