xref: /onnv-gate/usr/src/cmd/fm/fmd/common/fmd_list.c (revision 0:68f95e015346)
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 2004 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  * Embedded Linked Lists
31*0Sstevel@tonic-gate  *
32*0Sstevel@tonic-gate  * Simple doubly-linked list implementation.  This implementation assumes that
33*0Sstevel@tonic-gate  * each list element contains an embedded fmd_list_t (previous and next
34*0Sstevel@tonic-gate  * pointers), which is typically the first member of the element struct.
35*0Sstevel@tonic-gate  * An additional fmd_list_t is used to store the head (l_next) and tail
36*0Sstevel@tonic-gate  * (l_prev) pointers.  The current head and tail list elements have their
37*0Sstevel@tonic-gate  * previous and next pointers set to NULL, respectively.
38*0Sstevel@tonic-gate  *
39*0Sstevel@tonic-gate  * NOTE: The embeddable list code in this file intentionally provides no
40*0Sstevel@tonic-gate  * locking of any kind.  The implementation of any list in fmd must provide
41*0Sstevel@tonic-gate  * an appropriate locking strategy to protect the list or to protect access
42*0Sstevel@tonic-gate  * to the embedded fmd_list_t inside of each list element to avoid corruption.
43*0Sstevel@tonic-gate  * Refer to comments in the source files that use fmd_list_t for lock details.
44*0Sstevel@tonic-gate  */
45*0Sstevel@tonic-gate 
46*0Sstevel@tonic-gate #include <fmd_subr.h>
47*0Sstevel@tonic-gate #include <fmd_list.h>
48*0Sstevel@tonic-gate 
49*0Sstevel@tonic-gate void
fmd_list_append(fmd_list_t * lp,void * new)50*0Sstevel@tonic-gate fmd_list_append(fmd_list_t *lp, void *new)
51*0Sstevel@tonic-gate {
52*0Sstevel@tonic-gate 	fmd_list_t *p = lp->l_prev;	/* p = tail list element */
53*0Sstevel@tonic-gate 	fmd_list_t *q = new;		/* q = new list element */
54*0Sstevel@tonic-gate 
55*0Sstevel@tonic-gate 	lp->l_prev = q;
56*0Sstevel@tonic-gate 	q->l_prev = p;
57*0Sstevel@tonic-gate 	q->l_next = NULL;
58*0Sstevel@tonic-gate 
59*0Sstevel@tonic-gate 	if (p != NULL) {
60*0Sstevel@tonic-gate 		ASSERT(p->l_next == NULL);
61*0Sstevel@tonic-gate 		p->l_next = q;
62*0Sstevel@tonic-gate 	} else {
63*0Sstevel@tonic-gate 		ASSERT(lp->l_next == NULL);
64*0Sstevel@tonic-gate 		lp->l_next = q;
65*0Sstevel@tonic-gate 	}
66*0Sstevel@tonic-gate }
67*0Sstevel@tonic-gate 
68*0Sstevel@tonic-gate void
fmd_list_prepend(fmd_list_t * lp,void * new)69*0Sstevel@tonic-gate fmd_list_prepend(fmd_list_t *lp, void *new)
70*0Sstevel@tonic-gate {
71*0Sstevel@tonic-gate 	fmd_list_t *p = new;		/* p = new list element */
72*0Sstevel@tonic-gate 	fmd_list_t *q = lp->l_next;	/* q = head list element */
73*0Sstevel@tonic-gate 
74*0Sstevel@tonic-gate 	lp->l_next = p;
75*0Sstevel@tonic-gate 	p->l_prev = NULL;
76*0Sstevel@tonic-gate 	p->l_next = q;
77*0Sstevel@tonic-gate 
78*0Sstevel@tonic-gate 	if (q != NULL) {
79*0Sstevel@tonic-gate 		ASSERT(q->l_prev == NULL);
80*0Sstevel@tonic-gate 		q->l_prev = p;
81*0Sstevel@tonic-gate 	} else {
82*0Sstevel@tonic-gate 		ASSERT(lp->l_prev == NULL);
83*0Sstevel@tonic-gate 		lp->l_prev = p;
84*0Sstevel@tonic-gate 	}
85*0Sstevel@tonic-gate }
86*0Sstevel@tonic-gate 
87*0Sstevel@tonic-gate void
fmd_list_insert_before(fmd_list_t * lp,void * before_me,void * new)88*0Sstevel@tonic-gate fmd_list_insert_before(fmd_list_t *lp, void *before_me, void *new)
89*0Sstevel@tonic-gate {
90*0Sstevel@tonic-gate 	fmd_list_t *p = before_me;
91*0Sstevel@tonic-gate 	fmd_list_t *q = new;
92*0Sstevel@tonic-gate 
93*0Sstevel@tonic-gate 	if (p == NULL || p->l_prev == NULL) {
94*0Sstevel@tonic-gate 		fmd_list_prepend(lp, new);
95*0Sstevel@tonic-gate 		return;
96*0Sstevel@tonic-gate 	}
97*0Sstevel@tonic-gate 
98*0Sstevel@tonic-gate 	q->l_prev = p->l_prev;
99*0Sstevel@tonic-gate 	q->l_next = p;
100*0Sstevel@tonic-gate 	p->l_prev = q;
101*0Sstevel@tonic-gate 	q->l_prev->l_next = q;
102*0Sstevel@tonic-gate }
103*0Sstevel@tonic-gate 
104*0Sstevel@tonic-gate void
fmd_list_insert_after(fmd_list_t * lp,void * after_me,void * new)105*0Sstevel@tonic-gate fmd_list_insert_after(fmd_list_t *lp, void *after_me, void *new)
106*0Sstevel@tonic-gate {
107*0Sstevel@tonic-gate 	fmd_list_t *p = after_me;
108*0Sstevel@tonic-gate 	fmd_list_t *q = new;
109*0Sstevel@tonic-gate 
110*0Sstevel@tonic-gate 	if (p == NULL || p->l_next == NULL) {
111*0Sstevel@tonic-gate 		fmd_list_append(lp, new);
112*0Sstevel@tonic-gate 		return;
113*0Sstevel@tonic-gate 	}
114*0Sstevel@tonic-gate 
115*0Sstevel@tonic-gate 	q->l_next = p->l_next;
116*0Sstevel@tonic-gate 	q->l_prev = p;
117*0Sstevel@tonic-gate 	p->l_next = q;
118*0Sstevel@tonic-gate 	q->l_next->l_prev = q;
119*0Sstevel@tonic-gate }
120*0Sstevel@tonic-gate 
121*0Sstevel@tonic-gate void
fmd_list_delete(fmd_list_t * lp,void * existing)122*0Sstevel@tonic-gate fmd_list_delete(fmd_list_t *lp, void *existing)
123*0Sstevel@tonic-gate {
124*0Sstevel@tonic-gate 	fmd_list_t *p = existing;
125*0Sstevel@tonic-gate 
126*0Sstevel@tonic-gate 	if (p->l_prev != NULL)
127*0Sstevel@tonic-gate 		p->l_prev->l_next = p->l_next;
128*0Sstevel@tonic-gate 	else
129*0Sstevel@tonic-gate 		lp->l_next = p->l_next;
130*0Sstevel@tonic-gate 
131*0Sstevel@tonic-gate 	if (p->l_next != NULL)
132*0Sstevel@tonic-gate 		p->l_next->l_prev = p->l_prev;
133*0Sstevel@tonic-gate 	else
134*0Sstevel@tonic-gate 		lp->l_prev = p->l_prev;
135*0Sstevel@tonic-gate }
136