Description

This blog introduce some multi-thread tools of C++11.

Overview

lock tools: mutex, unique_lock, lock_guard
thread tools: thread, future, package_task
thread switching tools: condition_variable
function tools: lambda, bind

In multi-thread program, using lock tools to lock code, using thread tools to alloc/manage thread, using switching tools to achieve multi-thread switch, using function tools can simply code.

Lambda

format： [capture list] (parameter list) -> return type { function body }
example:

int exparam = 3;
auto func = [exparam](double a, double b) -> int {
	return a + b + exparam;
};
std::cout << func(1, 2.1) << std::endl; // output will be 6.

In some situation, we can simply lambda like:

1	auto func = [] { return 3; };

mutex and Lock

1	#include <mutex>

std::mutex is synchronization primitive to protect data from multi-thread access. It’s base method is lock and unlock, only one thread can own a mutex object in the same time.
std::lock_guard, 构造参数为mutex，在构造的时候调用lock，析构的时候unlock。
std::unique_lock，构造参数为mutex，和lock_unique的主要区别是：在拥有lock_guard的功能基础上，可以自己控制lock/unlock，且可以和其他unique_lock对象交换状态。

condition_variable

include <condition_variable>
std::condition_variable, 同步原语, 有方法：notify_one, notify_all, wait, wait_for, wait_util
wait相关函数，需要传入一个unique_lock，在wait的过程中暂时释放锁，等有notify事件产生，再取回锁的使用权。

线程

include
std::thread, 构造参数为func, f_param1, f_param2, …, 其中func是函数，f_param是函数需要的参数。