2N/A/*
2N/A * CDDL HEADER START
2N/A *
2N/A * The contents of this file are subject to the terms of the
2N/A * Common Development and Distribution License (the "License").
2N/A * You may not use this file except in compliance with the License.
2N/A *
2N/A * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
2N/A * or http://www.opensolaris.org/os/licensing.
2N/A * See the License for the specific language governing permissions
2N/A * and limitations under the License.
2N/A *
2N/A * When distributing Covered Code, include this CDDL HEADER in each
2N/A * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
2N/A * If applicable, add the following below this CDDL HEADER, with the
2N/A * fields enclosed by brackets "[]" replaced with your own identifying
2N/A * information: Portions Copyright [yyyy] [name of copyright owner]
2N/A *
2N/A * CDDL HEADER END
2N/A */
2N/A/*
2N/A * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
2N/A */
2N/A
2N/A/*
2N/A * Embedded Linked Lists
2N/A *
2N/A * Simple doubly-linked list implementation. This implementation assumes that
2N/A * each list element contains an embedded shadow_list_t (previous and next
2N/A * pointers), which is typically the first member of the element struct.
2N/A * An additional shadow_list_t is used to store the head (l_next) and tail
2N/A * (l_prev) pointers. The current head and tail list elements have their
2N/A * previous and next pointers set to NULL, respectively.
2N/A */
2N/A
2N/A#include <assert.h>
2N/A#include <shadow_impl.h>
2N/A
2N/Avoid
2N/Ashadow_list_append(shadow_list_t *lp, void *new)
2N/A{
2N/A shadow_list_t *p = lp->l_prev; /* p = tail list element */
2N/A shadow_list_t *q = new; /* q = new list element */
2N/A
2N/A lp->l_prev = q;
2N/A q->l_prev = p;
2N/A q->l_next = NULL;
2N/A
2N/A if (p != NULL) {
2N/A assert(p->l_next == NULL);
2N/A p->l_next = q;
2N/A } else {
2N/A assert(lp->l_next == NULL);
2N/A lp->l_next = q;
2N/A }
2N/A}
2N/A
2N/Avoid
2N/Ashadow_list_prepend(shadow_list_t *lp, void *new)
2N/A{
2N/A shadow_list_t *p = new; /* p = new list element */
2N/A shadow_list_t *q = lp->l_next; /* q = head list element */
2N/A
2N/A lp->l_next = p;
2N/A p->l_prev = NULL;
2N/A p->l_next = q;
2N/A
2N/A if (q != NULL) {
2N/A assert(q->l_prev == NULL);
2N/A q->l_prev = p;
2N/A } else {
2N/A assert(lp->l_prev == NULL);
2N/A lp->l_prev = p;
2N/A }
2N/A}
2N/A
2N/Avoid
2N/Ashadow_list_insert_before(shadow_list_t *lp, void *before_me, void *new)
2N/A{
2N/A shadow_list_t *p = before_me;
2N/A shadow_list_t *q = new;
2N/A
2N/A if (p == NULL || p->l_prev == NULL) {
2N/A shadow_list_prepend(lp, new);
2N/A return;
2N/A }
2N/A
2N/A q->l_prev = p->l_prev;
2N/A q->l_next = p;
2N/A p->l_prev = q;
2N/A q->l_prev->l_next = q;
2N/A}
2N/A
2N/Avoid
2N/Ashadow_list_insert_after(shadow_list_t *lp, void *after_me, void *new)
2N/A{
2N/A shadow_list_t *p = after_me;
2N/A shadow_list_t *q = new;
2N/A
2N/A if (p == NULL || p->l_next == NULL) {
2N/A shadow_list_append(lp, new);
2N/A return;
2N/A }
2N/A
2N/A q->l_next = p->l_next;
2N/A q->l_prev = p;
2N/A p->l_next = q;
2N/A q->l_next->l_prev = q;
2N/A}
2N/A
2N/Avoid
2N/Ashadow_list_delete(shadow_list_t *lp, void *existing)
2N/A{
2N/A shadow_list_t *p = existing;
2N/A
2N/A if (p->l_prev != NULL)
2N/A p->l_prev->l_next = p->l_next;
2N/A else
2N/A lp->l_next = p->l_next;
2N/A
2N/A if (p->l_next != NULL)
2N/A p->l_next->l_prev = p->l_prev;
2N/A else
2N/A lp->l_prev = p->l_prev;
2N/A}