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Problem breaking loop (with close button) in main thread [message #59034]

Tue, 18 October 2022 17:19

awksed
Messages: 68
Registered: April 2012

Member

Windows 7. U++ 16270. Multi-thread app.

I have a GuiAcquireMutex() function called from a main thread Paint() that calls

WaitForSingleObject(hMutex, dwShortTimeout) // dwShortTimeout = 1 second (full timeout is 60 seconds)

if the mutex is not acquired I call:

Ctrl::GuiSleep(1000) to allow other threads to run and if 60 seconds have not elapsed, jump
back to WaitForSingleObject().

I wish to allow the close button to call Close() (that sets boolean g_bQuit) and allow the user
close the app (breaking the mutex acquire loop).

Clicking the close button results in the windows message "... is not responding".

Adding Ctrl::ProcessEvents() causes a "WM_PAINT invoked ... while in Paint routine" error.

Is there some way in U++ to allow the close button to call Close() while the main thread is looping
(like Windows PumpWaitingMessages())?

Code:

DWORD GuiAcquireMutex(HANDLE hMutex, DWORD dwTimeout)
{
 if(hMutex == INVALID_HANDLE_VALUE)
   return ERROR_INVALID_HANDLE;
 
 long long llNow;
 long long llStart        = GetMilliTime();
 long long llEnd          = llStart + (long long) dwTimeout;
 DWORD     dwShortTimeout = 1000;        // 1 second
 DWORD     dwLastError;
 DWORD     dwWaitResult;

Again:

 dwLastError  = 0; // Success
 dwWaitResult = WaitForSingleObject(hMutex, dwShortTimeout);

 switch(dwWaitResult)
  {
   case WAIT_FAILED:

        llNow = GetMilliTime();
        
        if(llNow < llEnd)
         {
          if(g_bQuit)
           {
            dwLastError = ERROR_COUNTER_TIMEOUT;

            SetLastError(dwLastError);
            return dwLastError;
           }
          
          Ctrl::GuiSleep(1000); // Never sleeps for 1000 ms (always returns immediately)
          goto Again;
         }

        dwLastError = GetLastError();
        break;

   case WAIT_TIMEOUT:

        llNow = GetMilliTime();
        
        if(llNow < llEnd)
         {
          if(g_bQuit)
           {
            dwLastError = ERROR_COUNTER_TIMEOUT;

            SetLastError(dwLastError);
            return dwLastError;
           }
           
          Ctrl::GuiSleep(1000); // Never sleeps for 1000 ms (always returns immediately)
          goto Again;
         }

        dwLastError = ERROR_COUNTER_TIMEOUT;

        SetLastError(dwLastError);
  }

 return dwLastError;
}

Thanks.

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