C++11 C++；使用静态互斥对象&；赛况我用静态互斥体C++类作为类的私有成员来保护类中的另一个公共函数中的CUT。但当我从两个线程调用类的对象时，我得到了一个竞速条件。不知道为什么 class ThreadSafePrint { public: void myprint(int threadNumber) { std::lock_guard<std::mutex> gaurd(mymutex); cout <<"Thread " << threadNumber << endl; } private: static std::mutex mymutex; }; std::mutex ThreadSafePrint::mymutex; int main() { ThreadSafePrint obj; std::vector<std::thread> workers; int threadNumber; // create 2 threads and pass a number for(int i=0; i<2;++i) { // threadNumber = 0 for 1st thread if(i==0) { threadNumber = i; } // threadNumber = 1 for 2nd thread if(i==1) { threadNumber = i; } workers.push_back(std::thread([&obj,&threadNumber]() { obj.myprint(threadNumber); })); } // join all threads std::for_each(workers.begin(), workers.end(),[](std::thread & th) { th.join(); }); return 0; }_C++11

C++11 C++；使用静态互斥对象&；赛况我用静态互斥体C++类作为类的私有成员来保护类中的另一个公共函数中的CUT。但当我从两个线程调用类的对象时，我得到了一个竞速条件。不知道为什么 class ThreadSafePrint { public: void myprint(int threadNumber) { std::lock_guard<std::mutex> gaurd(mymutex); cout <<"Thread " << threadNumber << endl; } private: static std::mutex mymutex; }; std::mutex ThreadSafePrint::mymutex; int main() { ThreadSafePrint obj; std::vector<std::thread> workers; int threadNumber; // create 2 threads and pass a number for(int i=0; i<2;++i) { // threadNumber = 0 for 1st thread if(i==0) { threadNumber = i; } // threadNumber = 1 for 2nd thread if(i==1) { threadNumber = i; } workers.push_back(std::thread([&obj,&threadNumber]() { obj.myprint(threadNumber); })); } // join all threads std::for_each(workers.begin(), workers.end(),[](std::thread & th) { th.join(); }); return 0; }

c++11

C++11 C++；使用静态互斥对象&；赛况我用静态互斥体C++类作为类的私有成员来保护类中的另一个公共函数中的CUT。但当我从两个线程调用类的对象时，我得到了一个竞速条件。不知道为什么 class ThreadSafePrint { public: void myprint(int threadNumber) { std::lock_guard<std::mutex> gaurd(mymutex); cout <<"Thread " << threadNumber << endl; } private: static std::mutex mymutex; }; std::mutex ThreadSafePrint::mymutex; int main() { ThreadSafePrint obj; std::vector<std::thread> workers; int threadNumber; // create 2 threads and pass a number for(int i=0; i<2;++i) { // threadNumber = 0 for 1st thread if(i==0) { threadNumber = i; } // threadNumber = 1 for 2nd thread if(i==1) { threadNumber = i; } workers.push_back(std::thread([&obj,&threadNumber]() { obj.myprint(threadNumber); })); } // join all threads std::for_each(workers.begin(), workers.end(),[](std::thread & th) { th.join(); }); return 0; },c++11,C++11,在两个工作线程中捕获对局部变量threadNumber的引用，在两个线程中访问它，并在主线程中对其进行变异，而不进行任何同步。这确实是一种竞赛条件。取而代之的是按价值捕获 workers.push_back(std::thread([&obj, threadNumber]() 在两个工作线程中捕获对局部变量threadNumber的引用，在两个线程中访问它，并在主线程中对其进行变异，而不进行任何同步。这确实是一种竞赛条件。取而代之的是按价值捕获 workers.push_back

在两个工作线程中捕获对局部变量

threadNumber

的引用，在两个线程中访问它，并在主线程中对其进行变异，而不进行任何同步。这确实是一种竞赛条件。取而代之的是按价值捕获

 workers.push_back(std::thread([&obj, threadNumber]()

在两个工作线程中捕获对局部变量

threadNumber

的引用，在两个线程中访问它，并在主线程中对其进行变异，而不进行任何同步。这确实是一种竞赛条件。取而代之的是按价值捕获

 workers.push_back(std::thread([&obj, threadNumber]()

您必须通过值而不是引用来捕获

threadNumber

交换：

workers.push_back(std::thread([&obj,&threadNumber]()

借

否则，通过第二次循环运行，第一个线程的变量

threadNumber

也将改变

#include <iostream>
#include <thread>
#include <mutex>
#include <vector>
#include <algorithm>

class ThreadSafePrint
{
    public:
        void myprint(int threadNumber)
        {
            std::lock_guard<std::mutex> gaurd(mymutex);
            std::cout <<"Thread " << threadNumber << std::endl;
        }
    private:
        static std::mutex mymutex;
};

std::mutex ThreadSafePrint::mymutex;


int main()
{
    ThreadSafePrint obj;

    std::vector<std::thread> workers;

    int threadNumber;
    // create 2 threads and pass a number 
    for(int i=0; i<2;++i)
    {
        // threadNumber = 0 for 1st thread
        if(i==0)
        {
            threadNumber = i;
        }
        // threadNumber = 1 for 2nd thread
        if(i==1)
        {
            threadNumber = i;
        }

        workers.push_back(std::thread([&obj,threadNumber]()
        {
            obj.myprint(threadNumber);
        }));

    }

    // join all threads
    std::for_each(workers.begin(), workers.end(),[](std::thread & th)
    {
        th.join();
    });

    return 0;
}

#包括
#包括
#包括
#包括
#包括
类线程安全打印
{
公众：
void myprint（int threadNumber）
{
std：：锁定保护gaurd（mymutex）；
std:：cout您必须通过值而不是引用来捕获threadNumber

交换：
workers.push_back(std::thread([&obj,&threadNumber]()

借
否则，通过第二次循环运行，第一个线程的变量threadNumber
也将改变
#include <iostream>
#include <thread>
#include <mutex>
#include <vector>
#include <algorithm>

class ThreadSafePrint
{
    public:
        void myprint(int threadNumber)
        {
            std::lock_guard<std::mutex> gaurd(mymutex);
            std::cout <<"Thread " << threadNumber << std::endl;
        }
    private:
        static std::mutex mymutex;
};

std::mutex ThreadSafePrint::mymutex;


int main()
{
    ThreadSafePrint obj;

    std::vector<std::thread> workers;

    int threadNumber;
    // create 2 threads and pass a number 
    for(int i=0; i<2;++i)
    {
        // threadNumber = 0 for 1st thread
        if(i==0)
        {
            threadNumber = i;
        }
        // threadNumber = 1 for 2nd thread
        if(i==1)
        {
            threadNumber = i;
        }

        workers.push_back(std::thread([&obj,threadNumber]()
        {
            obj.myprint(threadNumber);
        }));

    }

    // join all threads
    std::for_each(workers.begin(), workers.end(),[](std::thread & th)
    {
        th.join();
    });

    return 0;
}

#包括
#包括
#包括
#包括
#包括
类线程安全打印
{
公众：
void myprint（int threadNumber）
{
std：：锁定保护gaurd（mymutex）；
std:：cout创建线程时，显式要求编译器向线程提供对主函数/线程正在使用的变量threadNumber
的同一实例的访问权限
[&threadNumber]

再次强调：这是一个明确的共享
事实上，您的代码表明您可能希望在尝试线程之前更好地掌握该语言，这段代码非常奇怪：
int threadNumber;
// create 2 threads and pass a number 
for(int i=0; i<2;++i)
{
  // threadNumber = 0 for 1st thread
  if(i==0)
  {
      threadNumber = i;
  }
  // threadNumber = 1 for 2nd thread
  if(i==1)
  {
      threadNumber = i;
  }

创建线程时，显式要求编译器向线程提供对主函数/线程正在使用的变量threadNumber
的同一实例的访问权限
[&threadNumber]

再次强调：这是一个明确的共享
事实上，您的代码表明您可能希望在尝试线程之前更好地掌握该语言，这段代码非常奇怪：
int threadNumber;
// create 2 threads and pass a number 
for(int i=0; i<2;++i)
{
  // threadNumber = 0 for 1st thread
  if(i==0)
  {
      threadNumber = i;
  }
  // threadNumber = 1 for 2nd thread
  if(i==1)
  {
      threadNumber = i;
  }