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 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1988 AT&T */
28 /* All Rights Reserved */
29
30 /*
31 * Tree search algorithm, generalized from Knuth (6.2.2) Algorithm T.
32 *
33 * The NODE * arguments are declared in the lint files as char *,
34 * because the definition of NODE isn't available to the user.
35 */
36
37 #pragma weak _tfind = tfind
38
39 #include "lint.h"
40 #include <mtlib.h>
41 #include <sys/types.h>
42 #include <search.h>
43 #include <thread.h>
44 #include <synch.h>
45
46 typedef struct node { void *key; struct node *llink, *rlink; } NODE;
47
48
49 /* tfind - find a node, or return 0 */
50 /*
51 * ky is Key to be located
52 * rtp is the Address of the root of the tree
53 * compar is the Comparison function
54 */
55 void *
tfind(const void * ky,void * const * rtp,int (* compar)(const void *,const void *))56 tfind(const void *ky, void *const *rtp,
57 int (*compar)(const void *, const void *))
58 {
59 void *key = (char *)ky;
60 NODE **rootp = (NODE **)rtp;
61 if (rootp == NULL)
62 return (NULL);
63 while (*rootp != NULL) { /* T1: */
64 int r = (*compar)(key, (*rootp)->key); /* T2: */
65 if (r == 0)
66 return ((void *)*rootp); /* Key found */
67 rootp = (r < 0) ?
68 &(*rootp)->llink : /* T3: Take left branch */
69 &(*rootp)->rlink; /* T4: Take right branch */
70 }
71 return (NULL);
72 }
73