c++ - Win32 线程生产者更新消费者线程

Question

我正在尝试使用基于类的 Win32 线程实现来创建生产者线程和消费者线程。消费者中int x类型的信息由生产者更新。

Producer and Consumer both inherit from IRunnable
struct IRunnable {
    virtual unsigned long run() = 0;
    virtual void stop() = 0;
};

它为 Thread 类创建一个接口(interface)，

class Thread {
public:
    Thread(IRunnable *ptr=0) {
        _runnable = ptr;
        _started = false;
        _threadHandle = 0;
    }

一个线程在线程类中被创建

DWORD threadID=0;
_threadHandle = ::CreateThread(0, 0, ThreadProc, this, 0, &threadID);

和

static unsigned long __stdcall ThreadProc(void* ptr) 
{
return ((Thread *)ptr)->run();
}

我是怎么用的

    int _tmain(int argc, _TCHAR* argv[]) {
     //example of usage



    Consumer *obj1=0;

    Thread *consumerThread=0;

    try {
        // create the threadable object first
    Consumer *obj1 = new Consumer();

        // create and start the thread the thread
        Thread *consumerThread = new Thread(obj1);
        consumerThread->start();


        printf("OkCon.\n");

    } 
    catch (ThreadException &e)
    {
        printf(e.Message.c_str());  
    }


    Producer *obj=0;
    Thread *ProducerThread=0;

    try {
        // create the threadable object first
        Producer *obj = new Producer();
        obj->Init(obj1);

        // create and start the thread the thread
        Thread *ProducerThread = new Thread(obj);
        ProducerThread->start();

        printf("OkProdu.\n");

    } 
    catch (ThreadException &e)
    {
        printf(e.Message.c_str());  
    }



    for(int i = 0; i<1000000; i++)
    {int a = i;}// just lets the program run on a bit so the threads can run and do a bit more work

    delete obj;
    delete ProducerThread;
    delete obj1;
    delete consumerThread;

    return 0;
}

消费者的运行函数是

unsigned long Consumer::run()
{
    while(_continue)
    {
        printf("readX, %d \n",x);

    }

    return 0;
}

生产者的init函数和run函数是

void Producer::Init(Consumer* aConsumer)
{
    consData = aConsumer;

}

unsigned long Producer::run()
{ 
    while(_continue)
    {       
        this->consData->x = 1;
    }
    return 0;
}

线程::运行是

unsigned long run() {
        _started = true;
        unsigned long threadExitCode = _runnable->run();
        _started = false;
        return threadExitCode;
    }

当我运行代码时，出现未处理的异常。访问冲突写入位置 0X... 在行 this->consData->x = 1;

如有任何帮助，我们将不胜感激。

Answer 1

在第一个 try block 中，您将 Consumer 实例分配给新创建的局部变量 Consumer *obj1，而不是使用在 try block 之前创建的现有变量。尝试这样的事情:

Consumer *obj1=0;
Thread *consumerThread=0;

try {
    // create the threadable object first
    obj1 = new Consumer();

这会修改现有变量而不是创建新变量。 Producer *obj、Thread *consumerThread 和 Thread *ProducerThread 的情况相同。请阅读有关 C++ 中变量的作用域和生命周期的内容。