C++ 线程：如何在另一个线程仍在运行时停止一个线程的执行 (Win32)

Question

The problem persists on Win32 environment in Visual Studio.
I have 2 classes:

void classA::DoSth(HWND param){
for(int i = 0; i<24; i++)
    std::cout<<i<<"\n";

}

void classB::DataGood(HWND param){
    std::cout<<"OKAY\n";
}

Implemantation file: Implementation.cpp

UINT startDAQThread(LPVOID param)
{
    theApp.myClassB = new ClassB;  //reference to  theApp found below
    theApp.myClassB->DataGood((HWND)param);     //continually looks for  data
    return(0);
}

UINT startAlgorithmThread(LPVOID param)
{
    theApp.classAPtr->DoSth((HWND)param);
    return(0);
}

BOOL Implementation::OnInitDialog(){
    AfxBeginThread(startDAQThread, GetSafeHwnd(), THREAD_PRIORITY_NORMAL);

    Sleep(1000);
    AfxBeginThread(startAlgorithmThread, GetSafeHwnd(), THREAD_PRIORITY_ABOVE_NORMAL);

    return TRUE;// #define TRUE 1

}

MainApp.h

class MainApp:public CWinApp{
    MainApp();

};
extern MainApp theApp;

MainApp.cpp

MainApp theApp;

Output:

1
2
3
OKAY
4
5
OKAY
6
7
8
OKAY
9-23

How do I make sure the loop completes its run first and then some other execution?

---

Research I have done:

As a beginner, I did make some effort to try to add a mutex and restrict resource sharing. I did not succeed since I could not figure out what resource is being shared between two classes/functions

I have made sure all #includes are included and the program compiles and runs

Answer 1

The ideal "shared resource" you are looking for in this case would be a condition variable - another mean of threads synchronisation.

You can read more about them here - https://thispointer.com/c11-multithreading-part-7-condition-variables-explained/

Essentially you would maintain a "flag" (ie conditional variable), that the tread that runs a loop would signal when it's done printing the numbers.

The other thread will be blocked (if you synchronise them properly), until the conditional variable is signalled to be changed by the first thread.