1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate * CDDL HEADER START
3*0Sstevel@tonic-gate *
4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance
7*0Sstevel@tonic-gate * with the License.
8*0Sstevel@tonic-gate *
9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate * and limitations under the License.
13*0Sstevel@tonic-gate *
14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate *
20*0Sstevel@tonic-gate * CDDL HEADER END
21*0Sstevel@tonic-gate */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
24*0Sstevel@tonic-gate * Use is subject to license terms.
25*0Sstevel@tonic-gate */
26*0Sstevel@tonic-gate
27*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI"
28*0Sstevel@tonic-gate
29*0Sstevel@tonic-gate /*
30*0Sstevel@tonic-gate * Simple doubly-linked list implementation. This implementation assumes that
31*0Sstevel@tonic-gate * each list element contains an embedded dt_list_t (previous and next
32*0Sstevel@tonic-gate * pointers), which is typically the first member of the element struct.
33*0Sstevel@tonic-gate * An additional dt_list_t is used to store the head (dl_next) and tail
34*0Sstevel@tonic-gate * (dl_prev) pointers. The current head and tail list elements have their
35*0Sstevel@tonic-gate * previous and next pointers set to NULL, respectively.
36*0Sstevel@tonic-gate */
37*0Sstevel@tonic-gate
38*0Sstevel@tonic-gate #include <unistd.h>
39*0Sstevel@tonic-gate #include <assert.h>
40*0Sstevel@tonic-gate #include <dt_list.h>
41*0Sstevel@tonic-gate
42*0Sstevel@tonic-gate void
dt_list_append(dt_list_t * dlp,void * new)43*0Sstevel@tonic-gate dt_list_append(dt_list_t *dlp, void *new)
44*0Sstevel@tonic-gate {
45*0Sstevel@tonic-gate dt_list_t *p = dlp->dl_prev; /* p = tail list element */
46*0Sstevel@tonic-gate dt_list_t *q = new; /* q = new list element */
47*0Sstevel@tonic-gate
48*0Sstevel@tonic-gate dlp->dl_prev = q;
49*0Sstevel@tonic-gate q->dl_prev = p;
50*0Sstevel@tonic-gate q->dl_next = NULL;
51*0Sstevel@tonic-gate
52*0Sstevel@tonic-gate if (p != NULL) {
53*0Sstevel@tonic-gate assert(p->dl_next == NULL);
54*0Sstevel@tonic-gate p->dl_next = q;
55*0Sstevel@tonic-gate } else {
56*0Sstevel@tonic-gate assert(dlp->dl_next == NULL);
57*0Sstevel@tonic-gate dlp->dl_next = q;
58*0Sstevel@tonic-gate }
59*0Sstevel@tonic-gate }
60*0Sstevel@tonic-gate
61*0Sstevel@tonic-gate void
dt_list_prepend(dt_list_t * dlp,void * new)62*0Sstevel@tonic-gate dt_list_prepend(dt_list_t *dlp, void *new)
63*0Sstevel@tonic-gate {
64*0Sstevel@tonic-gate dt_list_t *p = new; /* p = new list element */
65*0Sstevel@tonic-gate dt_list_t *q = dlp->dl_next; /* q = head list element */
66*0Sstevel@tonic-gate
67*0Sstevel@tonic-gate dlp->dl_next = p;
68*0Sstevel@tonic-gate p->dl_prev = NULL;
69*0Sstevel@tonic-gate p->dl_next = q;
70*0Sstevel@tonic-gate
71*0Sstevel@tonic-gate if (q != NULL) {
72*0Sstevel@tonic-gate assert(q->dl_prev == NULL);
73*0Sstevel@tonic-gate q->dl_prev = p;
74*0Sstevel@tonic-gate } else {
75*0Sstevel@tonic-gate assert(dlp->dl_prev == NULL);
76*0Sstevel@tonic-gate dlp->dl_prev = p;
77*0Sstevel@tonic-gate }
78*0Sstevel@tonic-gate }
79*0Sstevel@tonic-gate
80*0Sstevel@tonic-gate void
dt_list_insert(dt_list_t * dlp,void * after_me,void * new)81*0Sstevel@tonic-gate dt_list_insert(dt_list_t *dlp, void *after_me, void *new)
82*0Sstevel@tonic-gate {
83*0Sstevel@tonic-gate dt_list_t *p = after_me;
84*0Sstevel@tonic-gate dt_list_t *q = new;
85*0Sstevel@tonic-gate
86*0Sstevel@tonic-gate if (p == NULL || p->dl_next == NULL) {
87*0Sstevel@tonic-gate dt_list_append(dlp, new);
88*0Sstevel@tonic-gate return;
89*0Sstevel@tonic-gate }
90*0Sstevel@tonic-gate
91*0Sstevel@tonic-gate q->dl_next = p->dl_next;
92*0Sstevel@tonic-gate q->dl_prev = p;
93*0Sstevel@tonic-gate p->dl_next = q;
94*0Sstevel@tonic-gate q->dl_next->dl_prev = q;
95*0Sstevel@tonic-gate }
96*0Sstevel@tonic-gate
97*0Sstevel@tonic-gate void
dt_list_delete(dt_list_t * dlp,void * existing)98*0Sstevel@tonic-gate dt_list_delete(dt_list_t *dlp, void *existing)
99*0Sstevel@tonic-gate {
100*0Sstevel@tonic-gate dt_list_t *p = existing;
101*0Sstevel@tonic-gate
102*0Sstevel@tonic-gate if (p->dl_prev != NULL)
103*0Sstevel@tonic-gate p->dl_prev->dl_next = p->dl_next;
104*0Sstevel@tonic-gate else
105*0Sstevel@tonic-gate dlp->dl_next = p->dl_next;
106*0Sstevel@tonic-gate
107*0Sstevel@tonic-gate if (p->dl_next != NULL)
108*0Sstevel@tonic-gate p->dl_next->dl_prev = p->dl_prev;
109*0Sstevel@tonic-gate else
110*0Sstevel@tonic-gate dlp->dl_prev = p->dl_prev;
111*0Sstevel@tonic-gate }
112