Linux C++ 使用condition实现阻塞队列的方法

实例如下：

/*
* 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_ */

/*
 * 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;
    }
}

#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;
}