Basic usage of std::thread

1. Create and use threads 

void showInfo()
{
    std::thread::id id = std::this_thread::get_id();//当前线程id
    debug "执行showInfo()" << std::hash<std::thread::id>()(id);
}

• Specify a function when creating a thread object, and run this function in other threads:

    std::thread t1{showInfo};

int main(int argc, char *argv[])
{
    std::thread t1{showInfo};
    std::thread t2{showInfo};

    t1.join();//等待线程运行
    t2.join();

    std::thread::id id1 = t1.get_id();
    std::thread::id id2 = t2.get_id();
    std::thread::id id = std::this_thread::get_id();//当前线程id

    debug std::hash<std::thread::id>()(id1);
    debug std::hash<std::thread::id>()(id2);
    debug std::hash<std::thread::id>()(id);
}

• Specify the function object when creating a thread

struct ceshi
{
    void operator () ()
    {
        debug "run ceshi";
    }
};

int main(int argc, char *argv[])
{
    std::thread t1{ceshi()};

    t1.join();//等待线程运行

    std::thread::id id1 = t1.get_id();
    debug std::hash<std::thread::id>()(id1);
}

2. Passing parameters

void showInfo(const QString & string)
{
    debug "执行showInfo() start";
    debug "当前线程id = " <<std::hash<std::thread::id>()(std::this_thread::get_id());
    debug string;
    debug "执行showInfo() end";
}

int main(int argc, char *argv[])
{
    std::thread t1{showInfo,"我是一个字符串11111"};
    t1.join();

    debug endl;

    std::thread t2{showInfo,"我是一个字符串22222"};
    t2.join();
}

When passing a non-const reference, add std::ref(), otherwise the compilation may fail:

void showInfo(QString & string)
{
    debug string;
}

int main(int argc, char *argv[])
{
    QString src = "我是一个字符串";
    std::thread t1{showInfo,std::ref(src)};
    t1.join();
}