c++11新特性：可以用库函数创建平台无关的多线程

cpp_thread.cpp

#include <iostream>
#include <thread>
#include <chrono>  // 时间
#include <algorithm>
using namespace std;
using namespace std::chrono;
typedef unsigned long ul;

ul OddSum = 0;
ul EvenSum = 0;

void findOdd(ul start, ul end) {
    for(ul i = start; i <= end; ++i) {
        if((i & 1) == 1) {
            OddSum += i;
        }
    }
}

void findEven(ul start, ul end) {
    for(ul i = start; i <= end; ++i) {
        if((i & 1) == 0) {
            EvenSum += i;
        }
    }
}


// 创建线程的5中方法
namespace sanjay2 {
    // 1. Function pointer
    void fun(int x) {
        while(x-- > 0) {
            cout << x << endl;
        }
    }
    void test1() {
        std::thread t(fun, 10);
        t.join();
    }

    // 2. lambda function
    void test2() {
        auto fun = [](int x) {
            while(x-- > 0) {
                cout << x << endl;
            }
        };

        std::thread t(fun, 11);
        //更紧凑的写法
        std::thread t2([](int x) {
            while (x-- > 0) {
                cout << x << endl;
            }
        }, 12); // 这样会和t线程输出信息混合，输出有点乱
        t.join();
        t2.join();
    }
    // 3. functor (function object)
    class Base{
    public:
        void operator()(int x) {
            while (x-- > 0) {
                cout << x << endl;
            }
        }
    };
    void test3() {
        std::thread t(Base(), 14);
        t.join();
    }

    // 4. non-static member function
    class Base1{
    public:
        void run(int x) {
            while (x-- > 0) {
                cout << x << endl;
            }
        }
        static void fun(int x) {
            while (x-- > 0) {
                cout << x << endl;
            }
        }
    };
    void test4() {
        Base1 b;
        std::thread t(&Base1::run, &b, 15);
        t.join();
    }

    // 5. static member function
    void test5() {
        std::thread t(&Base1::fun, 16);
        t.join();
    }
}

// try_lock
#include <mutex>
namespace sanjay3 {
    int counter = 0;
    std::mutex mtx;

    void increaseTheCounter100000Time() {
        for(int i = 0; i < 100000; ++i) {
//            if(mtx.try_lock()) {
//                ++counter;
//                mtx.unlock();
//            }
            //如果换成
            mtx.lock();
            ++counter;
            mtx.unlock();
        }
    }

    void test() {
        std::thread t1(increaseTheCounter100000Time);
        std::thread t2(increaseTheCounter100000Time);

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

        cout << "counter could increase upto " << counter << endl;
    }
}


int main() {

    /*
    ul start = 0, end = 19000000000;

    auto start_time = high_resolution_clock::now();

//    findOdd(start, end);
//    findEven(start, end);

    // 用线程来执行
    thread t1(findOdd, start, end);
    thread t2(findEven, start, end);

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

    auto end_time = high_resolution_clock::now();

    auto duration = duration_cast<microseconds>(end_time - start_time);

    cout << "OddSum : " << OddSum << endl;
    cout << "EvenSum : " << EvenSum << endl;

    cout << "Duration: " << duration.count() / 1000000 << endl;

     */

//    sanjay2::test5();

    sanjay3::test();
    return 0;
}