#pragma once
#include <condition_variable>
#include <mutex>
#include <deque>
template<class T>
class BlockQueue
{
public:
	typedef std::unique_lock<std::mutex> TLock;

	//maxCapacity為-1，代表隊列無最大限制
	explicit BlockQueue(const int maxCapacity = -1):m_maxCapacity(maxCapacity)
	{

	}

	size_t size()
	{
		TLock lock(m_mutex);
		return m_list.size();
	}

	void push_back(const T &item)
	{
		TLock lock(m_mutex);
		if (true == hasCapacity())
		{
			while (m_list.size() >= m_maxCapacity)
			{
				m_notFull.wait(lock);
			}
		}

		m_list.push_back(item);
		m_notEmpty.notify_all();
	}

	T pop()
	{
		TLock lock(m_mutex);
		while (m_list.empty())
		{
			m_notEmpty.wait(lock);
		}

		T temp = *m_list.begin();
		m_list.pop_front();

		m_notFull.notify_all();

		lock.unlock();
		return temp;
	}

	bool empty()
	{
		TLock lock(m_mutex);
		return m_list.empty();
	}

	bool full()
	{
		if (false == hasCapacity)
		{
			return false;
		}

		TLock lock(m_mutex);
		return m_list.size() >= m_maxCapacity;
	}

private:
	bool hasCapacity() const
	{
		return m_maxCapacity > 0;
	}

	typedef std::deque<T> TList;
	TList m_list;

	const int m_maxCapacity;

	std::mutex m_mutex;
	std::condition_variable m_notEmpty;
	std::condition_variable m_notFull;
};
 

測試程式碼

#include <iostream>
#include <thread>
#include <stdio.h>
#include "BlockQueue.hpp"
using namespace std;

typedef BlockQueue<int> TQueue;

void produce(TQueue &queue)
{
	const int num = 9;
	for (int i = 0; i < num; ++i)
	{
		queue.push_back(i);
	}
}

void consume(TQueue &queue)
{
	while (false==queue.empty())
	{
		int tmp = queue.pop();
		printf("%d\n", tmp);
		std::this_thread::sleep_for(chrono::seconds(1));
	}
}

int main()
{
	TQueue queue(2);
	std::thread t1(produce, std::ref(queue));
	std::thread t2(consume, std::ref(queue));
	std::thread t3(consume, std::ref(queue));
	t3.join();
	t2.join();
	t1.join();
	return 0;
}