1 /* 2 * queue.c, queue 3 * 4 * Copyright (c) 2009-2010 Wind River Systems, Inc. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 #include <stdlib.h> 20 21 #include <queue.h> 22 23 inline void __queue_init(struct queue *queue) 24 { 25 queue->head = NULL; 26 queue->tail = NULL; 27 queue->length = 0; 28 } 29 30 struct queue *queue_alloc(void) 31 { 32 struct queue *queue; 33 34 queue = malloc(sizeof(struct queue)); 35 if (queue) 36 __queue_init(queue); 37 38 return queue; 39 } 40 41 inline void __queue_free(struct queue *queue) 42 { 43 free(queue); 44 } 45 46 void queue_free_all(struct queue *queue) 47 { 48 struct list *list = queue->head; 49 50 list_free_all(list); 51 __queue_init(queue); 52 } 53 54 void __queue_push_head(struct queue *queue, struct list *entry) 55 { 56 queue->head = __list_add_head(queue->head, entry); 57 if (!queue->tail) 58 queue->tail = queue->head; 59 60 queue->length++; 61 } 62 63 int queue_push_head(struct queue *queue, void *data) 64 { 65 struct list *entry = list_alloc(data); 66 67 if (!entry) 68 return -1; 69 else 70 queue->head = __list_add_head(queue->head, entry); 71 72 if (!queue->tail) 73 queue->tail = queue->head; 74 75 queue->length++; 76 return 0; 77 } 78 79 void __queue_push_tail(struct queue *queue, struct list *entry) 80 { 81 queue->tail = list_add_tail(queue->tail, entry); 82 if (queue->tail == NULL) { 83 return; 84 } 85 if (queue->tail->next) 86 queue->tail = queue->tail->next; 87 else 88 queue->head = queue->tail; 89 90 queue->length++; 91 } 92 93 int queue_push_tail(struct queue *queue, void *data) 94 { 95 struct list *entry = list_alloc(data); 96 97 if (!entry) 98 return -1; 99 else 100 queue->tail = __list_add_tail(queue->tail, entry); 101 102 if (queue->tail->next) 103 queue->tail = queue->tail->next; 104 else 105 queue->head = queue->tail; 106 107 queue->length++; 108 return 0; 109 } 110 111 struct list *__queue_pop_head(struct queue *queue) 112 { 113 struct list *entry = queue->head; 114 115 if (entry) { 116 queue->head = __list_remove(queue->head, entry); 117 if (!queue->head) 118 queue->tail = NULL; 119 120 queue->length--; 121 } 122 123 return entry; 124 } 125 126 void *queue_pop_head(struct queue *queue) 127 { 128 struct list *entry; 129 void *data = NULL; 130 131 entry = __queue_pop_head(queue); 132 if (entry) { 133 data = entry->data; 134 __list_free(entry); 135 } 136 137 return data; 138 } 139 140 struct list *__queue_pop_tail(struct queue *queue) 141 { 142 struct list *entry = queue->tail; 143 struct list *prev; 144 145 if (entry) { 146 prev = entry->prev; 147 queue->head = __list_remove(queue->head, entry); 148 queue->tail = prev; 149 queue->length--; 150 } 151 152 return entry; 153 } 154 155 void *queue_pop_tail(struct queue *queue) 156 { 157 struct list *entry; 158 void *data = NULL; 159 160 entry = __queue_pop_tail(queue); 161 if (entry) { 162 data = entry->data; 163 __list_free(entry); 164 } 165 166 return data; 167 } 168 169 inline struct list *__queue_peek_head(struct queue *queue) 170 { 171 return queue->head; 172 } 173 174 inline struct list *__queue_peek_tail(struct queue *queue) 175 { 176 return queue->tail; 177 } 178 179 inline void *queue_peek_head(struct queue *queue) 180 { 181 struct list *entry; 182 void *data = NULL; 183 184 entry = __queue_peek_head(queue); 185 if (entry) 186 data = entry->data; 187 188 return data; 189 } 190 191 inline void *queue_peek_tail(struct queue *queue) 192 { 193 struct list *entry; 194 void *data = NULL; 195 196 entry = __queue_peek_tail(queue); 197 if (entry) 198 data = entry->data; 199 200 return data; 201 } 202 203 int queue_length(struct queue *queue) 204 { 205 return queue->length; 206 } 207
