2 цикла одновременно

while (GetMessage(&msg, nullptr, 0, 0))
{   
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }               
}
 
while(boolrun)
{
      Main();
      Sleep(100);
}

SetTimer(hWnd, 100, 100, NULL);

case WM_TIMER:
        Main();
        break;

VOID CALLBACK TimerProc(HWND hWnd, UINT uMsg, UINT idEvent, DWORD dwTime)

auto thread = std::thread([&]()
{
    while(boolrun)
    {
        Main();
        Sleep(100);
    }
});
 
while (GetMessage(&msg, nullptr, 0, 0))
{   
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }               
}
 
boolrun = false;
thread.join();

CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)Main, NULL, 0, NULL);

ExitThread(0);

boolrun = false;
::WaitForSingleObject(hThread, INFINITE);

// crt_begthrdex.cpp
// compile with: /MT
#include <windows.h>
#include <stdio.h>
#include <process.h>
 
unsigned Counter;
unsigned __stdcall SecondThreadFunc( void* pArguments )
{
    printf( "In second thread...\n" );
 
    while ( Counter < 1000000 )
        Counter++;
 
    _endthreadex( 0 );
    return 0;
}
 
int main()
{
    HANDLE hThread;
    unsigned threadID;
 
    printf( "Creating second thread...\n" );
 
    // Create the second thread.
    hThread = (HANDLE)_beginthreadex( NULL, 0, &SecondThreadFunc, NULL, 0, &threadID );
 
    // Wait until second thread terminates. If you comment out the line
    // below, Counter will not be correct because the thread has not
    // terminated, and Counter most likely has not been incremented to
    // 1000000 yet.
    WaitForSingleObject( hThread, INFINITE );
    printf( "Counter should be 1000000; it is-> %d\n", Counter );
    // Destroy the thread object.
    CloseHandle( hThread );
}

HANDLE hThread;
hThread = (HANDLE)_beginthreadex(NULL, 0, (_beginthreadex_proc_type)Main, NULL, 0, NULL);

    case WM_DESTROY:
        boolrun = FALSE;
        WaitForSingleObject(hThread, INFINITE);
        CloseHandle(hThread);
                PostQuitMessage(0);
             break;

VOID __stdcall Main(){
    while (SecontThread)
    {
        Sleep(100);
    }
    MessageBox(NULL, "End Thread", NULL, MB_OK);
    _endthreadex(0);
}

VOID __stdcall Main(){
    while (SecontThread)
    {
        if (boolrun)
        {
                     ...
                 }
        Sleep(100);
    }
    MessageBox(NULL, "End Thread", NULL, MB_OK);
    _endthreadex(0);
}

hThread = (HANDLE)_beginthreadex(NULL, 0, &Main, NULL, 0, NULL);

int APIENTRY wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLine, int nCmdShow)
{
...
}

_beginthreadex_proc_type __stdcall Main();

unsigned __stdcall Main(void *){

HANDLE hThread;

int APIENTRY wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLine, int nCmdShow)
{
...
hThread = (HANDLE)_beginthreadex(NULL, 0, &Main, NULL, 0, NULL);
...
}

case WM_DESTROY:
        boolrun = FALSE;
        SecontThread = FALSE;
        WaitForSingleObject(hThread, INFINITE);
        CloseHandle(hThread);
                PostQuitMessage(0);
        break;

unsigned __stdcall Main(void*){
    while (SecontThread)
    {
        if (boolrun)
        {
                    ...
                }
        Sleep(100);
    }
    MessageBox(NULL, "End Thread", NULL, MB_OK);
    return 0;
}