C++线程库

int main()
{
	std::thread t1;
	std::cout << t1.get_id() << std::endl;
	return 0;
}

// vs下查看
typedef struct
{ /* thread identifier for Win32 */
    void *_Hnd; /* Win32 HANDLE */
    unsigned int _Id;
} _Thrd_imp_t;

#include<iostream>
#include<thread>
void ThreadFunc(int a)
{
	std::cout << "thread1" << a << std::endl;
}

class TF
{
public:
	void operator()()
	{
		std::cout << "thread3" << std::endl;
	}
};
int main()
{
	//线程函数为函数指针
	std::thread t1(ThreadFunc, 10);

	//线程函数为lambda表达式
	std::thread t2([] {std::cout << "thread2" << std::endl; });

	//线程函数为函数对象
	TF tf;
	std::thread t3(tf);

	t1.join();
	t2.join();
	t3.join();

	std::cout << "Main thread!" << std::endl;

	return 0;
}

#include<iostream>
#include<thread>
void threadFunc1(int& x)
{
	x += 10;
}

void threadFunc2(int* x)
{
	*x += 10;
}

int main()
{
	int a = 10;
	//在线程函数中对a修改，不会影响外部实参，线程函数参数虽然是引用方式，但其实际引用的是线程栈中的拷贝
	std::thread t1(threadFunc1, a);
	t1.join();
	std::cout << a << std::endl;

	// 如果想要通过形参改变外部实参时，必须借助std::ref()函数
	std::thread t2(threadFunc1, std::ref(a));
	t2.join();
	std::cout << a << std::endl;

	//地址的拷贝
	std::thread t3(threadFunc2, &a);
	t3.join();
	std::cout << a << std::endl;


	return 0;
}

#include<iostream>
#include<thread>
unsigned long sum = 0L;

void fun(size_t num)
{
	for (size_t i = 0; i < num; ++i)
	{
		sum++;
	}
}

int main()
{
	std::cout << "Before joining,sum = " << sum <<std::endl;
	std::thread t1(fun, 10000000);
	std::thread t2(fun, 10000000);
	t1.join();
	t2.join();
	std::cout << "After joining,sum = " << sum << std::endl;
	return 0;
}

#include<iostream>
#include<mutex>
#include<thread>
unsigned long sum = 0L;
std::mutex _mutex;
void fun(size_t num)
{
	
	for (size_t i = 0; i < num; ++i)
	{
		_mutex.lock();
		sum++;
		_mutex.unlock();
	}
	
}

int main()
{
	
	std::cout << "Before joining,sum = " << sum <<std::endl;
	std::thread t1(fun, 10000000);
	std::thread t2(fun, 10000000);
	t1.join();
	t2.join();
	std::cout << "After joining,sum = " << sum << std::endl;
	return 0;
}

#include<iostream>
#include<thread>
#include<atomic>
std::atomic_long sum{ 0 };
void fun(size_t num)
{
	
	for (size_t i = 0; i < num; ++i)
	{
		sum++;
	}
	
}

int main()
{
	
	std::cout << "Before joining,sum = " << sum <<std::endl;
	std::thread t1(fun, 10000000);
	std::thread t2(fun, 10000000);
	t1.join();
	t2.join();
	std::cout << "After joining,sum = " << sum << std::endl;
	return 0;
}

atmoic<T> t; // 声明一个类型为T的原子类型变量t

#include <atomic>
int main()
{
    atomic<int> a1(0);
    //atomic<int> a2(a1); // 编译失败
    atomic<int> a2(0);
    //a2 = a1; // 编译失败
    return 0;
}

#include<iostream>
#include<mutex>
#include<thread>
#include<atomic>

std::mutex _mutex;
int number = 0;

void threadAdd()
{
	for (int i = 0; i < 100; ++i)
	{
		_mutex.lock();
		++number;
		std::cout << "thread 1: " << number << std::endl;
		_mutex.unlock();
	}
}

void threadDel()
{
	for (int i = 0; i < 100; ++i)
	{
		_mutex.lock();
		--number;
		std::cout << "thread 2: " << number << std::endl;
		_mutex.unlock();
	}
}
int main()
{
	std::thread t1(threadAdd);
	std::thread t2(threadDel);
	t1.join();
	t2.join();

	std::cout << "number:" << number << std::endl;
	system("pause");

	return 0;
}

//一般传入的就是互斥锁
template<class _Mutex>
class lock_guard
{
public:
	// 在构造lock_gard时，_Mtx还没有被上锁
	//explicit禁止隐式转换
	explicit lock_guard(_Mutex& _Mtx)
		: _MyMutex(_Mtx)
	{
		_MyMutex.lock();
	}
	// 在构造lock_gard时，_Mtx已经被上锁，此处不需要再上锁
	lock_guard(_Mutex& _Mtx, adopt_lock_t)
		: _MyMutex(_Mtx)
	{}
	~lock_guard() _NOEXCEPT
	{
		_MyMutex.unlock();
	}
	lock_guard(const lock_guard&) = delete;
	lock_guard& operator=(const lock_guard&) = delete;
private:
	_Mutex& _MyMutex;
};

#include<iostream>
#include<mutex>
#include<thread>
#include<condition_variable>
//支持两个线程交替打印，一个打印奇数，一个打印偶数
void two_thread_print()
{
	std::mutex _mutex;
	std::condition_variable cv;
	int n = 100;
	bool flag = true;//线程阻塞条件，false的时候，阻塞线程t1，true的时候阻塞线程t2
	std::thread t1([&]() {
		int i = 0;
		while (i < n)
		{
			std::unique_lock<std::mutex> lock(_mutex);//上锁
			cv.wait(lock, [&]()->bool {return flag; });//当返回true的时候，该线程不会被阻塞
			std::cout << "t1: "<< i << std::endl;
			flag = false;//条件改变
			i += 2;//偶数
			cv.notify_one();//唤醒满足条件的线程之一
		}
		});
	std::thread t2([&]() {
		int j = 1;
		while (j < n)
		{
			std::unique_lock<std::mutex> lock(_mutex);//上锁
			cv.wait(lock, [&]()->bool {return !flag; });//当返回为true的时候，该线程不会被阻塞
			std::cout << "t2: " << j << std::endl;
			flag = true;//改变条件
			j += 2;//奇数
			cv.notify_one();//唤醒满足条件的线程
		}
		});

	t1.join();
	t2.join();
}
int main()
{
	two_thread_print();
	return 0;
}