C++ 11实现信号量

谁践踏了优雅 2022-04-13 02:31 277阅读 0赞

/************************************/
    /* 文件名：CSemaphore.h		    */
    /* 功  能：C++11信号量		    */
    /************************************/
    
    #ifndef _CSEMAPHORE_H_
    #define _CSEMAPHORE_H_
    
    #include <mutex>
    #include <condition_variable>
    
    class CSemaphore
    {
    public:
    	CSemaphore(long count = 0);
    	void Signal();
    	void Wait();
    
    private:
    	std::mutex _mutex;
    	std::condition_variable _cv;
    	long m_count;
    };
    
    #endif /*_CSEMAPHORE_H_*/

/************************************/
    /* 文件名：CSemaphore.cpp	    */
    /* 功  能：C++11信号量		    */
    /************************************/
    #include "CSemaphore.h"
    
    CSemaphore::CSemaphore(long count)
    	:m_count(count)
    {
    }
    
    void CSemaphore::Signal()
    {
    	std::unique_lock<std::mutex> lock(_mutex);
    	++m_count;
    	_cv.notify_one();
    }
    
    void CSemaphore::Wait()
    {
    	std::unique_lock<std::mutex> lock(_mutex);
    	_cv.wait(lock, [=] {return m_count > 0; });
    	--m_count;
    }

/* 信号量使用示例 */
    #include "CSemaphore.h"
    #include <iostream>
    
    const int BufferSize = 128;
    const int DataSize = 500;
    
    int buff[BufferSize];
    CSemaphore freeSpace(BufferSize);//写入线程
    CSemaphore usedSpace(-100);//消费线程
    
    std::mutex m;
    
    void producer()
    {
    	for (int i = 0; i < DataSize; i++)
    	{
    		freeSpace.Wait();
    
    		std::thread::id thread_id = std::this_thread::get_id();
    		buff[i%BufferSize] = i;
    		printf("Thread %d，生产 %d\n", thread_id, i);
    
    		usedSpace.Signal();
    		Sleep(50);
    	}
    }
    
    void consumer()
    {
    	for (int i = 0; i < DataSize; i++)
    	{
    		usedSpace.Wait();
    
    		std::thread::id thread_id = std::this_thread::get_id();
    		printf("Thread %d，消费的数字 %d\n", thread_id, buff[i%BufferSize]);
    
    		freeSpace.Signal();
    	}
    }
    
    int main()
    {
    	std::thread threads1(producer);
    	std::thread threads2(consumer);
    
    	threads1.join();
    	threads2.join();
    	std::cout << "完成!" << std::endl;
    
    	std::cin.get();
    	return 0;
    }