Linux C++ 使用condition实现阻塞队列的方法_Linux

Linux C++ 使用condition实现阻塞队列的方法

2021-12-20 16:52Linux教程网 Linux

下面小编就为大家带来一篇Linux C++ 使用condition实现阻塞队列的方法。小编觉得挺不错的，现在就分享给大家，也给大家做个参考。一起跟随小编过来看看吧

实例如下：

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/*
 * BlockingQueue.h
 *
 * Created on: 2014年6月10日
 *   Author: 
 */
 
#ifndef BLOCKINGQUEUE_H_
#define BLOCKINGQUEUE_H_
 
#include <iostream>
#include <pthread.h>
 
using namespace std;
 
//template <typename T >
class BlockingQueue
{
public:
    BlockingQueue();
    BlockingQueue(int capacity);
    ~BlockingQueue();
 
    bool push(int item);
    int poll();
 
private:
    int capacity;
    int* queue;
    int head,tail;
    pthread_mutex_t mutex;
    pthread_cond_t notFull,notEmpty;
};
 
 
#endif /* BLOCKINGQUEUE_H_ */

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/*
 * BlockingQueue.cpp
 *
 *  Created on: 2014年6月10日
 *      Author: 
 */
#include "../include/BlockingQueue.h"
 
BlockingQueue::BlockingQueue()
{
    this->capacity = 10;
    queue = new int[capacity];
    head = 0,tail = 0;
    pthread_mutex_init(&mutex,NULL);
    pthread_cond_init(&notFull,NULL);
    pthread_cond_init(&notEmpty,NULL);
 
}
 
BlockingQueue::BlockingQueue(int capacity)
{
    this->capacity = capacity;
    queue = new int[capacity];
    cout << "capacity " << sizeof(queue) << endl;
    head = 0,tail = 0;
    pthread_mutex_init(&mutex,NULL);
    pthread_cond_init(&notFull,NULL);
    pthread_cond_init(&notEmpty,NULL);
 
}
 
BlockingQueue::~BlockingQueue()
{
    this->capacity = 0;
    head = 0,tail = 0;
    delete queue;
    pthread_mutex_destroy(&mutex);
    pthread_cond_destroy(&notFull);
    pthread_cond_destroy(&notEmpty);
}
 
bool BlockingQueue::push(int item)
{
    pthread_mutex_lock(&mutex);
    cout << "you want push " << item << endl;
    while((head + 1) % capacity == tail)//is full
    {
        cout << "is full,wait..." << endl;
        // push wait
        pthread_cond_wait(&notFull,&mutex);
        cout << "not full,unlock" << endl;
    }
 
    {
        queue[head] = item;
        head = (head + 1) % capacity;
        cout << "push " << item << endl;
        //wake up poll thread
        pthread_cond_signal(&notEmpty);
        pthread_mutex_unlock(&mutex);
 
        return true;
    }
}
 
int BlockingQueue::poll()
{
    pthread_mutex_lock(&mutex);
    int ret = 0;
    while(head == tail) // is empty
    {
        cout << "is empty,wait..." << endl;
        //poll wait
        pthread_cond_wait(&notEmpty,&mutex);
        cout << "not empty,unlock..." << endl;
    }
    {
        ret = queue[tail];
        tail = (tail + 1) % capacity;
        cout << "take " << ret << endl;
        //wake up push thread
        pthread_cond_signal(&notFull);
 
        pthread_mutex_unlock(&mutex);
        return ret;
    }
}

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#include <iostream>
#include "include/BlockingQueue.h"
using namespace std;
BlockingQueue queue(3);
 
void* put(void *)
{
    queue.push(1);
      queue.push(2);
      queue.push(3);
      queue.push(4);
      queue.push(5);
      return NULL;
}
 
void* take(void *)
{
    queue.poll();
    queue.poll();
    queue.poll();
    return NULL;
}
 
 
int main() {
 
    pthread_t put1,take1;
  pthread_create(&put1,NULL,put,0);
  pthread_create(&take1,NULL,take,0);
 
  void * retval;
  pthread_join(put1,&retval);
  pthread_join(take1,&retval);
 
    return 0;
}