1 /*
2 * Initial implementation:
3 * Copyright (c) 2002 Robert Drehmel
4 * All rights reserved.
5 *
6 * As long as the above copyright statement and this notice remain
7 * unchanged, you can do what ever you want with this file.
8 *
9 * $FreeBSD: src/lib/libc/stdlib/insque.c,v 1.3 2003/01/04 07:34:41 tjr Exp $
10 */
11
12 #define _SEARCH_PRIVATE
13 #include <search.h>
14 #ifdef DEBUG
15 #include <stdio.h>
16 #else
17 #include <stdlib.h> /* for NULL */
18 #endif
19
20 void
insque(void * element,void * pred)21 insque(void *element, void *pred)
22 {
23 struct que_elem *prev, *next, *elem;
24
25 elem = (struct que_elem *)element;
26 prev = (struct que_elem *)pred;
27
28 if (prev == NULL) {
29 elem->prev = elem->next = NULL;
30 return;
31 }
32
33 next = prev->next;
34 if (next != NULL) {
35 #ifdef DEBUG
36 if (next->prev != prev) {
37 fprintf(stderr, "insque: Inconsistency detected:"
38 " next(%p)->prev(%p) != prev(%p)\n",
39 next, next->prev, prev);
40 }
41 #endif
42 next->prev = elem;
43 }
44 prev->next = elem;
45 elem->prev = prev;
46 elem->next = next;
47 }
48