| /*-------------------------------------------------------------------------- |
| Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are met: |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| * Neither the name of Code Aurora nor |
| the names of its contributors may be used to endorse or promote |
| products derived from this software without specific prior written |
| permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| NON-INFRINGEMENT ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| --------------------------------------------------------------------------*/ |
| /* |
| Queue with Linked list |
| */ |
| |
| #include "queue.h" |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| |
| typedef struct Node |
| { |
| void *element; |
| struct Node *next; |
| } Node; |
| |
| struct Queue |
| { |
| Node *head; |
| Node *tail; |
| int current_size; |
| }; |
| |
| Queue *alloc_queue() |
| { |
| Queue *q = (Queue *) malloc(sizeof(Queue)); |
| if (q) |
| { |
| q->head = q->tail = NULL; |
| q->current_size = 0; |
| } |
| return q; |
| } |
| |
| void free_queue(Queue *q) |
| { |
| while (q->current_size) |
| { |
| pop(q); |
| } |
| } |
| |
| void free_queue_and_qelement(Queue *q) |
| { |
| while (q->current_size) |
| { |
| void *element = pop(q); |
| if (element) |
| free(element); |
| } |
| } |
| |
| int push(Queue *q, void * element) |
| { |
| Node *new_node = (Node *) malloc(sizeof(Node)); |
| |
| if (new_node == NULL) |
| return -1; |
| |
| new_node->element = element; |
| new_node->next = NULL; |
| |
| if (q->current_size == 0) |
| { |
| q->head = new_node; |
| } |
| else |
| { |
| q->tail->next = new_node; |
| } |
| |
| q->tail = new_node; |
| q->current_size++; |
| |
| return 0; |
| } |
| |
| void *pop(Queue *q) |
| { |
| Node *temp; |
| void *element; |
| |
| if (q->current_size == 0) |
| return NULL; |
| |
| temp = q->head; |
| element = temp->element; |
| |
| if (q->current_size == 1) |
| { |
| q->head = q->tail = NULL; |
| } |
| else |
| { |
| q->head = q->head->next; |
| } |
| |
| free(temp); |
| q->current_size--; |
| return element; |
| } |
| |