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, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 2002 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29/*
30 * Routines for manipulating a FIFO queue
31 */
32
33#include <stdlib.h>
34
35#include "fifo.h"
36#include "memory.h"
37
38typedef struct fifonode {
39	void *fn_data;
40	struct fifonode *fn_next;
41} fifonode_t;
42
43struct fifo {
44	fifonode_t *f_head;
45	fifonode_t *f_tail;
46};
47
48fifo_t *
49fifo_new(void)
50{
51	fifo_t *f;
52
53	f = xcalloc(sizeof (fifo_t));
54
55	return (f);
56}
57
58/* Add to the end of the fifo */
59void
60fifo_add(fifo_t *f, void *data)
61{
62	fifonode_t *fn = xmalloc(sizeof (fifonode_t));
63
64	fn->fn_data = data;
65	fn->fn_next = NULL;
66
67	if (f->f_tail == NULL)
68		f->f_head = f->f_tail = fn;
69	else {
70		f->f_tail->fn_next = fn;
71		f->f_tail = fn;
72	}
73}
74
75/* Remove from the front of the fifo */
76void *
77fifo_remove(fifo_t *f)
78{
79	fifonode_t *fn;
80	void *data;
81
82	if ((fn = f->f_head) == NULL)
83		return (NULL);
84
85	data = fn->fn_data;
86	if ((f->f_head = fn->fn_next) == NULL)
87		f->f_tail = NULL;
88
89	free(fn);
90
91	return (data);
92}
93
94/*ARGSUSED*/
95static void
96fifo_nullfree(void *arg)
97{
98	/* this function intentionally left blank */
99}
100
101/* Free an entire fifo */
102void
103fifo_free(fifo_t *f, void (*freefn)(void *))
104{
105	fifonode_t *fn = f->f_head;
106	fifonode_t *tmp;
107
108	if (freefn == NULL)
109		freefn = fifo_nullfree;
110
111	while (fn) {
112		(*freefn)(fn->fn_data);
113
114		tmp = fn;
115		fn = fn->fn_next;
116		free(tmp);
117	}
118
119	free(f);
120}
121
122int
123fifo_len(fifo_t *f)
124{
125	fifonode_t *fn;
126	int i;
127
128	for (i = 0, fn = f->f_head; fn; fn = fn->fn_next, i++);
129
130	return (i);
131}
132
133int
134fifo_empty(fifo_t *f)
135{
136	return (f->f_head == NULL);
137}
138
139int
140fifo_iter(fifo_t *f, int (*iter)(void *data, void *arg), void *arg)
141{
142	fifonode_t *fn;
143	int rc;
144	int ret = 0;
145
146	for (fn = f->f_head; fn; fn = fn->fn_next) {
147		if ((rc = iter(fn->fn_data, arg)) < 0)
148			return (-1);
149		ret += rc;
150	}
151
152	return (ret);
153}
154