fifo.c revision 178481
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