C++11 thread多线程编程创建方式

#include <iostream>
#include <utility>
#include <thread>
#include <chrono>
#include <functional>
#include <atomic>
 
void f1(int n)
{
  for (int i = 0; i < 5; ++i) {
    std::cout << "Thread " << n << " executing\n";
    std::this_thread::sleep_for(std::chrono::milliseconds(1000));
  }
}
 
void f2(int& n)
{
  std::cout << "thread-id:" << std::this_thread::get_id() << "\n";
  for (int i = 0; i < 5; ++i) {
    std::cout << "Thread 2 executing:" << n << "\n";
    ++n;
    std::this_thread::sleep_for(std::chrono::milliseconds(1000));
  }
}
 
int main()
{
  int n = 0;
  std::thread t1; // t1 is not a thread t1 不是一个线程
  std::thread t2(f1, n + 1); // pass by value 传值
  std::thread t3(f2, std::ref(n)); // pass by reference  传引用
 
  std::this_thread::sleep_for(std::chrono::milliseconds(2000));
  std::cout << "\nThread 4 create :\n";
  std::thread t4(std::move(t3)); // t4 is now running f2(). t3 is no longer a thread 这时候t3将不是线程,t4接替t3继续运行f2
  t2.join();
  t4.join();
  std::cout << "Final value of n is " << n << '\n';
}

#include <iostream>
#include <thread>
using namespace std;
 
void threadHandle1(int time)
{
	//让子线程睡眠time秒
	std::this_thread::sleep_for(std::chrono::seconds(time));
	cout << "hello thread1!" << endl;
}
void threadHandle2(int time)
{
	//让子线程睡眠time秒ace this_thread是namespace 
	std::this_thread::sleep_for(std::chrono::seconds(time));
	cout << "hello thread2!" << endl;
}
int main()
{
	//创建了一个线程对象,传入一个线程函数(作为线程入口函数),
	//新线程就开始运行了，没有先后顺序，随着CPU的调度算法执行 
	std::thread t1(threadHandle1, 2);
	std::thread t2(threadHandle2, 3);
 
	//主线程(main)运行到这里，等待子线程结束，主线程才继续往下运行
	t1.join();
	t2.join();
 
	//把子线程设置为分离线程，子线程和主线程就毫无关系了
	//主线程结束的时候查看其他线程
	//但是这个子线程运行完还是没运行完都和这个主线程没关系了
	//这个子线程就从这个main分离出去了
	//运行程序时也看不到这个子线程的任何输出打印了
    //t1.detach();
 
	cout << "main thread done!" << endl;
 
	//主线程运行完成，查看如果当前进程还有未运行完成的子线程
	//进程就会异常终止
	return 0;
}

		// CLASS TEMPLATE lock_guard
template<class _Mutex>
	class lock_guard
	{	// class with destructor that unlocks a mutex
public:
	using mutex_type = _Mutex;
 
	explicit lock_guard(_Mutex& _Mtx)
		: _MyMutex(_Mtx)
		{	// construct and lock
		_MyMutex.lock();
		}
 
	lock_guard(_Mutex& _Mtx, adopt_lock_t)
		: _MyMutex(_Mtx)
		{	// construct but don't lock
		}
 
	~lock_guard() noexcept
		{	// unlock
		_MyMutex.unlock();
		}
 
	lock_guard(const lock_guard&) = delete;
	lock_guard& operator=(const lock_guard&) = delete;
private:
	_Mutex& _MyMutex;
	};

template<class _Mutex>
	class unique_lock
	{	// whizzy class with destructor that unlocks mutex
public:
	typedef _Mutex mutex_type;
 
	// CONSTRUCT, ASSIGN, AND DESTROY
	unique_lock() noexcept
		: _Pmtx(nullptr), _Owns(false)
		{	// default construct
		}
 
	explicit unique_lock(_Mutex& _Mtx)
		: _Pmtx(_STD addressof(_Mtx)), _Owns(false)
		{	// construct and lock
		_Pmtx->lock();
		_Owns = true;
		}
 
	unique_lock(_Mutex& _Mtx, adopt_lock_t)
		: _Pmtx(_STD addressof(_Mtx)), _Owns(true)
		{	// construct and assume already locked
		}
 
	unique_lock(_Mutex& _Mtx, defer_lock_t) noexcept
		: _Pmtx(_STD addressof(_Mtx)), _Owns(false)
		{	// construct but don't lock
		}
 
	unique_lock(_Mutex& _Mtx, try_to_lock_t)
		: _Pmtx(_STD addressof(_Mtx)), _Owns(_Pmtx->try_lock())
		{	// construct and try to lock
		}
 
	template<class _Rep,
		class _Period>
		unique_lock(_Mutex& _Mtx,
			const chrono::duration<_Rep, _Period>& _Rel_time)
		: _Pmtx(_STD addressof(_Mtx)), _Owns(_Pmtx->try_lock_for(_Rel_time))
		{	// construct and lock with timeout
		}
 
	template<class _Clock,
		class _Duration>
		unique_lock(_Mutex& _Mtx,
			const chrono::time_point<_Clock, _Duration>& _Abs_time)
		: _Pmtx(_STD addressof(_Mtx)), _Owns(_Pmtx->try_lock_until(_Abs_time))
		{	// construct and lock with timeout
		}
 
	unique_lock(_Mutex& _Mtx, const xtime *_Abs_time)
		: _Pmtx(_STD addressof(_Mtx)), _Owns(false)
		{	// try to lock until _Abs_time
		_Owns = _Pmtx->try_lock_until(_Abs_time);
		}
 
	unique_lock(unique_lock&& _Other) noexcept
		: _Pmtx(_Other._Pmtx), _Owns(_Other._Owns)
		{	// destructive copy
		_Other._Pmtx = nullptr;
		_Other._Owns = false;
		}
 
	unique_lock& operator=(unique_lock&& _Other)
		{	// destructive copy
		if (this != _STD addressof(_Other))
			{	// different, move contents
			if (_Owns)
				_Pmtx->unlock();
			_Pmtx = _Other._Pmtx;
			_Owns = _Other._Owns;
			_Other._Pmtx = nullptr;
			_Other._Owns = false;
			}
		return (*this);
		}
 
	~unique_lock() noexcept
		{	// clean up
		if (_Owns)
			_Pmtx->unlock();
		}
 
	unique_lock(const unique_lock&) = delete;
	unique_lock& operator=(const unique_lock&) = delete;
 
	void lock()
		{	// lock the mutex
		_Validate();
		_Pmtx->lock();
		_Owns = true;
		}
 
	_NODISCARD bool try_lock()
		{	// try to lock the mutex
		_Validate();
		_Owns = _Pmtx->try_lock();
		return (_Owns);
		}
 
	template<class _Rep,
		class _Period>
		_NODISCARD bool try_lock_for(const chrono::duration<_Rep, _Period>& _Rel_time)
		{	// try to lock mutex for _Rel_time
		_Validate();
		_Owns = _Pmtx->try_lock_for(_Rel_time);
		return (_Owns);
		}
 
	template<class _Clock,
		class _Duration>
		_NODISCARD bool try_lock_until(const chrono::time_point<_Clock, _Duration>& _Abs_time)
		{	// try to lock mutex until _Abs_time
		_Validate();
		_Owns = _Pmtx->try_lock_until(_Abs_time);
		return (_Owns);
		}
 
	_NODISCARD bool try_lock_until(const xtime *_Abs_time)
		{	// try to lock the mutex until _Abs_time
		_Validate();
		_Owns = _Pmtx->try_lock_until(_Abs_time);
		return (_Owns);
		}
 
	void unlock()
		{	// try to unlock the mutex
		if (!_Pmtx || !_Owns)
			_THROW(system_error(
				_STD make_error_code(errc::operation_not_permitted)));
 
		_Pmtx->unlock();
		_Owns = false;
		}
 
	void swap(unique_lock& _Other) noexcept
		{	// swap with _Other
		_STD swap(_Pmtx, _Other._Pmtx);
		_STD swap(_Owns, _Other._Owns);
		}
 
	_Mutex *release() noexcept
		{	// disconnect
		_Mutex *_Res = _Pmtx;
		_Pmtx = nullptr;
		_Owns = false;
		return (_Res);
		}
 
	_NODISCARD bool owns_lock() const noexcept
		{	// return true if this object owns the lock
		return (_Owns);
		}
 
	explicit operator bool() const noexcept
		{	// return true if this object owns the lock
		return (_Owns);
		}
 
	_NODISCARD _Mutex *mutex() const noexcept
		{	// return pointer to managed mutex
		return (_Pmtx);
		}
 
private:
	_Mutex *_Pmtx;
	bool _Owns;
 
	void _Validate() const
		{	// check if the mutex can be locked
		if (!_Pmtx)
			_THROW(system_error(
				_STD make_error_code(errc::operation_not_permitted)));
 
		if (_Owns)
			_THROW(system_error(
				_STD make_error_code(errc::resource_deadlock_would_occur)));
		}
	};

?#include <iostream>
#include <atomic>//C++11线程库提供的原子类
#include <thread>//C++线程类库的头文件
#include <vector>
 
 
int count = 0;
 
//线程函数
void sumTask()
{
  
  //每个线程给count加10次
  for (int i = 0; i < 10; ++i)
  {
    count++;
    std::this_thread::sleep_for(std::chrono::milliseconds(10));
  }
}
 
int main()
{
  //创建10个线程放在容器当中
  std::vector<std::thread> vec;
  for (int i = 0; i < 10; ++i)
  {
    vec.push_back(std::thread(sumTask));
  }
 
  //等待线程执行完成
  for (unsigned int i = 0; i < vec.size(); ++i)
  {
    vec[i].join();
  }
 
  //所有子线程运行结束
  std::cout << "count : " << count << std::endl;
 
  return 0;
}
 
 
?

#include <iostream>
#include <atomic>//C++11线程库提供的原子类
#include <thread>//C++线程类库的头文件
#include <mutex>
#include <vector>
 
 
int count = 0;
std::mutex mutex;
 
//线程函数
void sumTask()
{
  
  //每个线程给count加10次
  for (int i = 0; i < 10; ++i)
  {
    {
      std::lock_guard<std::mutex> lock(mutex);
      count++;
    }
;
    std::this_thread::sleep_for(std::chrono::milliseconds(10));
  }
}
 
int main()
{
  //创建10个线程放在容器当中
  std::vector<std::thread> vec;
  for (int i = 0; i < 10; ++i)
  {
    vec.push_back(std::thread(sumTask));
  }
 
  //等待线程执行完成
  for (unsigned int i = 0; i < vec.size(); ++i)
  {
    vec[i].join();
  }
 
  //所有子线程运行结束，count的结果每次运行应该都是10000
  std::cout << "count : " << count << std::endl;
 
  return 0;
}

#include <iostream>
#include <atomic>//C++11线程库提供的原子类
#include <thread>//C++线程类库的头文件
#include <vector>
 
//原子整型，CAS操作保证给count自增自减的原子操作
std::atomic_int count = 0;
 
//线程函数
void sumTask()
{
  //每个线程给count加10次
  for (int i = 0; i < 10; ++i)
  {
    count++;
  }
}
 
int main()
{
  //创建10个线程放在容器当中
  std::vector<std::thread> vec;
  for (int i = 0; i < 10; ++i)
  {
    vec.push_back(std::thread(sumTask));
  }
 
  //等待线程执行完成
  for (unsigned int i = 0; i < vec.size(); ++i)
  {
    vec[i].join();
  }
 
  //所有子线程运行结束，count的结果每次运行应该都是10000
  std::cout << "count : " << count << std::endl;
 
  return 0;
}

#include <iostream>           //std::cout
#include <thread>             //std::thread
#include <mutex>              //std::mutex, std::unique_lock
#include <condition_variable> //std::condition_variable
#include <vector>
 
//定义互斥锁(条件变量需要和互斥锁一起使用)
std::mutex mtx;
//定义条件变量(用来做线程间的同步通信)
std::condition_variable cv;
//定义vector容器，作为生产者和消费者共享的容器
std::vector<int> vec;
 
//生产者线程函数
void producer()
{
  //生产者每生产一个，就通知消费者消费一个
  for (int i = 1; i <= 10; ++i)
  {
    //获取mtx互斥锁资源
    std::unique_lock<std::mutex> lock(mtx);
 
    //如果容器不为空，代表还有产品未消费，等待消费者线程消费完，再生产
    while (!vec.empty())
    {
      //判断容器不为空，进入等待条件变量的状态，释放mtx锁，
      //让消费者线程抢到锁能够去消费产品
      cv.wait(lock);
    }
    vec.push_back(i); // 表示生产者生产的产品序号i
    std::cout << "producer生产产品:" << i << std::endl;
 
    /*
    生产者线程生产完产品，通知等待在cv条件变量上的消费者线程，
    可以开始消费产品了，然后释放锁mtx
    */
    cv.notify_all();
 
    //生产一个产品，睡眠100ms
    std::this_thread::sleep_for(std::chrono::milliseconds(100));
  }
}
//消费者线程函数
void consumer()
{
  //消费者每消费一个，就通知生产者生产一个
  for (int i = 1; i <= 10; ++i)
  {
    //获取mtx互斥锁资源
    std::unique_lock<std::mutex> lock(mtx);
 
    //如果容器为空，代表还有没有产品可消费，等待生产者生产，再消费
    while (vec.empty())
    {
      //判断容器为空，进入等待条件变量的状态，释放mtx锁，
      //让生产者线程抢到锁能够去生产产品
      cv.wait(lock);
    }
    int data = vec.back(); // 表示消费者消费的产品序号i
    vec.pop_back();
    std::cout << "consumer消费产品:" << data << std::endl;
 
    /*
    消费者消费完产品，通知等待在cv条件变量上的生产者线程，
    可以开始生产产品了，然后释放锁mtx
    */
    cv.notify_all();
 
    //消费一个产品，睡眠100ms
    std::this_thread::sleep_for(std::chrono::milliseconds(100));
  }
}
int main()
{
  //创建生产者和消费者线程
  std::thread t1(producer);
  std::thread t2(consumer);
 
  //main主线程等待所有子线程执行完
  t1.join();
  t2.join();
 
  return 0;
}

#include <iostream>           //std::cout
#include <thread>             //std::thread
#include <mutex>              //std::mutex, std::unique_lock
#include <condition_variable> //std::condition_variable
#include <vector>
 
//锁资源1
std::mutex mtx1;
//锁资源2
std::mutex mtx2;
 
//线程A的函数
void taskA()
{
  //保证线程A先获取锁1
  std::lock_guard<std::mutex> lockA(mtx1);
  std::cout << "线程A获取锁1" << std::endl;
 
  //线程A睡眠2s再获取锁2，保证锁2先被线程B获取，模拟死锁问题的发生
  std::this_thread::sleep_for(std::chrono::seconds(2));
 
  //线程A先获取锁2
  std::lock_guard<std::mutex> lockB(mtx2);
  std::cout << "线程A获取锁2" << std::endl;
 
  std::cout << "线程A释放所有锁资源，结束运行！" << std::endl;
}
 
//线程B的函数
void taskB()
{
  //线程B先睡眠1s保证线程A先获取锁1
  std::this_thread::sleep_for(std::chrono::seconds(1));
  std::lock_guard<std::mutex> lockB(mtx2);
  std::cout << "线程B获取锁2" << std::endl;
 
  //线程B尝试获取锁1
  std::lock_guard<std::mutex> lockA(mtx1);
  std::cout << "线程B获取锁1" << std::endl;
 
  std::cout << "线程B释放所有锁资源，结束运行！" << std::endl;
}
int main()
{
  //创建生产者和消费者线程
  std::thread t1(taskA);
  std::thread t2(taskB);
 
  //main主线程等待所有子线程执行完
  t1.join();
  t2.join();
 
  return 0;
}

#include <iostream>           //std::cout
#include <thread>             //std::thread
#include <mutex>              //std::mutex, std::unique_lock
#include <condition_variable> //std::condition_variable
#include <vector>
 
//锁资源1
std::mutex mtx1;
//锁资源2
std::mutex mtx2;
 
//线程A的函数
void taskA()
{
  //保证线程A先获取锁1
  std::lock_guard<std::mutex> lockA(mtx1);
  std::cout << "线程A获取锁1" << std::endl;
 
  //线程A睡眠2s再获取锁2，保证锁2先被线程B获取，模拟死锁问题的发生
  std::this_thread::sleep_for(std::chrono::seconds(2));
 
  //线程A先获取锁2
  std::lock_guard<std::mutex> lockB(mtx2);
  std::cout << "线程A获取锁2" << std::endl;
 
  std::cout << "线程A释放所有锁资源，结束运行！" << std::endl;
}
 
//线程B的函数
void taskB()
{
  while (true)
  {
 
  }
}
int main()
{
  //创建生产者和消费者线程
  std::thread t1(taskA);
  std::thread t2(taskB);
 
  //main主线程等待所有子线程执行完
  t1.join();
  t2.join();
 
  return 0;
}