C++11中條件標量和互斥鎖應用出現死鎖問題

更新時間：2023年06月06日 15:00:47 作者：hsy12342611

這篇文章主要介紹了C++11中條件標量和互斥鎖應用出現死鎖思考,本文通過示例代碼給大家介紹的非常詳細，對大家的學習或工作具有一定的參考借鑒價值，需要的朋友可以參考下

1.測試程序1

#include <mutex>
#include <deque>
#include <iostream>
#include <thread>
#include <condition_variable>
class MCTest {
public:
	MCTest() : m_work(true), m_max_num(30), m_next_index(0) {
	}
	void producer_thread() {
		while (m_work) {
			std::this_thread::sleep_for(std::chrono::milliseconds(500));
			std::unique_lock<std::mutex> lk(m_cvMutex);
			m_cv.wait(lk);
			m_data.push_back(m_next_index++);
			std::cout << "producer " << m_next_index << ", queue size: " << m_data.size() << std::endl;
			m_cv.notify_all();
		}
	}
	void consumer_thread() {
		while (m_work) {
            std::unique_lock<std::mutex> lk(m_cvMutex);
            m_cv.wait(lk);
		    int data = m_data.front();
		    m_data.pop_front();
		    std::cout << "consumer " << data << ", deque size: " << m_data.size() << std::endl;
		    m_cv.notify_all();
		}
	}
private:
	bool m_work;
	std::mutex m_cvMutex;
	std::condition_variable m_cv;
	std::deque<int> m_data;
	size_t m_max_num;
	int m_next_index;
};
int main() {
	MCTest obj;
	std::thread tp = std::thread(&MCTest::producer_thread, &obj);
	std::thread tc = std::thread(&MCTest::consumer_thread, &obj);
    tp.join();
    tc.join();
	return 0;
}

運行結果：

2.測試程序2

#include <mutex>
#include <deque>
#include <iostream>
#include <thread>
#include <condition_variable>
class MCTest {
public:
	MCTest() : m_work(true), m_max_num(30), m_next_index(0) {
	}
	void producer_thread() {
		while (m_work) {
			std::this_thread::sleep_for(std::chrono::milliseconds(500));
			std::unique_lock<std::mutex> lk(m_cvMutex);
			m_cv.wait(lk, [this]() -> bool { return this->m_data.size() < this->m_max_num; });
			m_data.push_back(m_next_index++);
			std::cout << "producer " << m_next_index << ", queue size: " << m_data.size() << std::endl;
			m_cv.notify_all();
		}
	}
	void consumer_thread() {
		while (m_work) {
            std::unique_lock<std::mutex> lk(m_cvMutex);
            m_cv.wait(lk, [this] { return !this->m_data.empty(); });
		    int data = m_data.front();
		    m_data.pop_front();
		    std::cout << "consumer " << data << ", deque size: " << m_data.size() << std::endl;
		    m_cv.notify_all();
		}
	}
private:
	bool m_work;
	std::mutex m_cvMutex;
	std::condition_variable m_cv;
	std::deque<int> m_data;
	size_t m_max_num;
	int m_next_index;
};
int main() {
	MCTest obj;
	std::thread tp = std::thread(&MCTest::producer_thread, &obj);
	std::thread tc = std::thread(&MCTest::consumer_thread, &obj);
    tp.join();
    tc.join();
	return 0;
}

運行結果：