59 lines
1.4 KiB
C
59 lines
1.4 KiB
C
#include "../include/queue.h"
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#include "../include/memory.h"
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#include "../include/graphics.h"
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#include "../include/io.h"
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Queue *create_queue() {
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Queue *queue = (Queue *) kmalloc(sizeof(Queue));
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queue->phead = NULL;
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queue->ptail = NULL;
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queue->size = 0;
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return queue;
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}
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void free_queue(Queue *queue) {
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QNode *cur = queue->phead;
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while (cur) {
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QNode *next = cur->next;
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kfree(cur);
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cur = next;
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}
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queue->phead = queue->ptail = NULL;
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kfree(queue);
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}
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void queue_push(Queue *pq, char x) {
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QNode *newnode = (QNode *) kmalloc(sizeof(QNode));//为新节点申请内存空间
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if (newnode == NULL) {
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printf("OUT_OF_MEMORY: The kernel memory out of.");
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io_cli();
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for (;;)io_hlt();
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}
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newnode->data = x; //新节点储存数据
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newnode->next = NULL;//新节点的下一个指向NULL，即新节点作为队尾
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if (pq->phead == NULL)//将新节点入队
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{
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pq->phead = pq->ptail = newnode;
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pq->phead->next = newnode;
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} else {
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pq->ptail->next = newnode;
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pq->ptail = newnode;
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}
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pq->size++;
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}
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char queue_pop(Queue *pq) {
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if (pq->size == 0)return NULL;
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QNode *next = pq->phead->next;
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kfree(pq->phead);
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pq->phead = next;
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if (pq->phead == NULL) {
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pq->ptail = NULL;
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}
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pq->size -= 1;
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return next->data;
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}
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