xref: /titanic_41/usr/src/cmd/syslogd/list.c (revision bfed486ad8de8b8ebc6345a8e10accae08bf2f45)
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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <pthread.h>
29 #include <malloc.h>
30 #include <memory.h>
31 #include <assert.h>
32 #include <poll.h>
33 #include <stdio.h>
34 #include "llt.h"
35 void
36 ll_init(llh_t *head)
37 {
38 	head->back = &head->front;
39 	head->front = NULL;
40 }
41 void
42 ll_enqueue(llh_t *head, ll_t *data)
43 {
44 	data->n = NULL;
45 	*head->back = data;
46 	head->back = &data->n;
47 }
48 /*
49  * apply the function func to every element of the ll in sequence.  Can
50  * be used to free up the element, so "n" is computed before func is
51  * called on it.
52  */
53 void
54 ll_mapf(llh_t *head, void (*func)(void *))
55 {
56 	ll_t *t = head->front;
57 	ll_t *n;
58 
59 	while (t) {
60 		n = t->n;
61 		func(t);
62 		t = n;
63 	}
64 }
65 ll_t *
66 ll_peek(llh_t *head)
67 {
68 	return (head->front);
69 }
70 ll_t *
71 ll_dequeue(llh_t *head)
72 {
73 	ll_t *ptr;
74 	ptr = head->front;
75 	if (ptr && ((head->front = ptr->n) == NULL))
76 		head->back = &head->front;
77 	return (ptr);
78 }
79 ll_t *
80 ll_traverse(llh_t *ptr, int (*func)(void *, void *), void *user)
81 {
82 	ll_t *t;
83 	ll_t **prev = &ptr->front;
84 
85 	t = ptr->front;
86 	while (t) {
87 		switch (func(t, user)) {
88 		case 1:
89 			return (NULL);
90 		case 0:
91 			prev = &(t->n);
92 			t = t->n;
93 			break;
94 		case -1:
95 			if ((*prev = t->n) == NULL)
96 				ptr->back = prev;
97 			return (t);
98 		}
99 	}
100 	return (NULL);
101 }
102 /* Make sure the list isn't corrupt and returns number of list items */
103 int
104 ll_check(llh_t *head)
105 {
106 	int i = 0;
107 	ll_t *ptr = head->front;
108 	ll_t **prev = &head->front;
109 
110 	while (ptr) {
111 		i++;
112 		prev = &ptr->n;
113 		ptr = ptr->n;
114 	}
115 	assert(head->back == prev);
116 	return (i);
117 }
118