110 lines
2.4 KiB
C
110 lines
2.4 KiB
C
/*
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* Copyright 2021 Regents of the University of Michigan
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "queue.h"
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#include "xalloc.h"
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#include <pthread.h>
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zqueue_t *queue_init(void)
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{
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zqueue_t *p = xmalloc(sizeof(zqueue_t));
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p->front = NULL;
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p->back = NULL;
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p->size = 0;
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pthread_mutex_init(&p->lock, NULL);
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pthread_cond_init(&p->empty, NULL);
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return p;
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}
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int is_empty(zqueue_t *queue) { return queue->size == 0; }
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void push_back(char *data, zqueue_t *queue)
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{
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znode_t *new_node = xmalloc(sizeof(znode_t));
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new_node->prev = NULL;
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new_node->next = NULL;
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new_node->data = strdup(data);
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pthread_mutex_lock(&queue->lock);
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if (is_empty(queue)) {
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queue->front = new_node;
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queue->back = new_node;
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} else {
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queue->back->next = new_node;
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new_node->prev = queue->back;
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queue->back = new_node;
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}
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queue->size++;
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pthread_cond_signal(&queue->empty);
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pthread_mutex_unlock(&queue->lock);
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}
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znode_t *pop_front(zqueue_t *queue)
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{
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pthread_mutex_lock(&queue->lock);
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while (is_empty(queue)) {
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pthread_cond_wait(&queue->empty, &queue->lock);
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}
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znode_t *temp = pop_front_unsafe(queue);
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pthread_mutex_unlock(&queue->lock);
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return temp;
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}
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znode_t *pop_front_unsafe(zqueue_t *queue)
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{
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znode_t *temp = queue->front;
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queue->front = temp->next;
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if (queue->front != NULL) {
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queue->front->prev = NULL;
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}
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queue->size--;
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return temp;
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}
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znode_t *get_front(zqueue_t *queue)
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{
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pthread_mutex_lock(&queue->lock);
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while (is_empty(queue)) {
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pthread_cond_wait(&queue->empty, &queue->lock);
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}
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znode_t *temp = xmalloc(sizeof(znode_t));
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temp = queue->front;
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pthread_mutex_unlock(&queue->lock);
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return temp;
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}
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znode_t *get_back(zqueue_t *queue)
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{
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pthread_mutex_lock(&queue->lock);
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while (is_empty(queue)) {
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pthread_cond_wait(&queue->empty, &queue->lock);
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}
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znode_t *temp = xmalloc(sizeof(znode_t));
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temp = queue->back;
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pthread_mutex_unlock(&queue->lock);
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return temp;
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}
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size_t get_size(zqueue_t *queue) { return queue->size; }
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