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  4. How to pause processing?

How to pause processing?

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  • J Johan Pretorius

    When your application receives the WM_KILLFOCUS message then set the thread priority to BelowNormal or Lowest or make the application thread sleep. Hope it helps


    Artificial Intelligence is no match for Natural Stupidity
    No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
    I can't always be wrong ... or can I?

    D Offline
    D Offline
    Dustin Henry
    wrote on last edited by
    #3

    That doesn't seem to work. Am I doing this correctly? I have never created/manipulated threads before.

    case WM_ACTIVATE:
    {
    	// See if we lost or gained focus
    	if (LOWORD(wParam) == WA_ACTIVE)
    	{
    		HANDLE thread = GetCurrentThread();
    		SetThreadPriority(thread, THREAD_PRIORITY_NORMAL);
    	}
    	else
    	{
    		HANDLE thread = GetCurrentThread();
    		SetThreadPriority(thread, THREAD_PRIORITY_LOWEST);
    	}
    }
    break;
    

    I also tried doing it on the WM_KILLFOCUS event but with the same results. Thanks, Dustin

    J 1 Reply Last reply
    0
    • D Dustin Henry

      That doesn't seem to work. Am I doing this correctly? I have never created/manipulated threads before.

      case WM_ACTIVATE:
      {
      	// See if we lost or gained focus
      	if (LOWORD(wParam) == WA_ACTIVE)
      	{
      		HANDLE thread = GetCurrentThread();
      		SetThreadPriority(thread, THREAD_PRIORITY_NORMAL);
      	}
      	else
      	{
      		HANDLE thread = GetCurrentThread();
      		SetThreadPriority(thread, THREAD_PRIORITY_LOWEST);
      	}
      }
      break;
      

      I also tried doing it on the WM_KILLFOCUS event but with the same results. Thanks, Dustin

      J Offline
      J Offline
      Johan Pretorius
      wrote on last edited by
      #4

      Something i forgot when you posted was that you wanted to pause the processing not lower it. try this if it does not work try send me an demo so i can test.

      //add global variable to main.cpp
      static bool g_bRunning = true;
      
      //Modify case statement
      case WM_ACTIVATE:
      {
         //See if we lost or gained focus
         if (LOWORD(wParam) == WA_ACTIVE)
         {
           g_bRunning = true;
         }
         else
         {
           g_bRunning = false;
         }
      }
      break;
      
      //add to main loop
      while (!g_bRunning){/*leave empty*/};//this should pause it.
      
      //just add an mutex and !!
      

      Artificial Intelligence is no match for Natural Stupidity
      No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
      I can't always be wrong ... or can I?

      D 1 Reply Last reply
      0
      • D Dustin Henry

        I have an application with a main processing loop ( while(true){} ). When the application is running normally it eats up about 2% of the CPU. Whenever focus is taken away from the application window however, the CPU usage jumps to about 50%. This also happens when I comment out all of my code in the loop except the windows message queue processing and my app jumps from 60fps to about 2000fps. My question is, how do I 'pause' processing when focus is taken away, but still have the abilty to get window messages so I know when focus is given back? Thanks in advance, Dustin

        M Offline
        M Offline
        Mark Salsbery
        wrote on last edited by
        #5

        Dustin Henry wrote:

        I comment out all of my code in the loop except the windows message queue processing and my app jumps from 60fps to about 2000fps.

        What do you mean by "fps"? Typically a Windows message loop uses virtually no CPU until a message is received. What's going on in your message loop? Mark

        D J 2 Replies Last reply
        0
        • M Mark Salsbery

          Dustin Henry wrote:

          I comment out all of my code in the loop except the windows message queue processing and my app jumps from 60fps to about 2000fps.

          What do you mean by "fps"? Typically a Windows message loop uses virtually no CPU until a message is received. What's going on in your message loop? Mark

          D Offline
          D Offline
          Dustin Henry
          wrote on last edited by
          #6

          fps = Frames per second. It is a Direct3D application. Typically a Windows message loop uses virtually no CPU until a message is received I thought the same thing, but if I comment out all of my processing except for the message peek and dispatch, the app still eats the CPU when focus is lost. Here is my entire WindowProc:

          LRESULT CALLBACK WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
          {	 
          	switch(msg)
          	{	
          		case WM_CREATE: 
          		{  
          			// do initialization stuff here
          			// return success
          			return(0);
          		} 
          		break;
          		case WM_LBUTTONDOWN:
          		{
          			// get the position of the mouse
          			POINT ptMouse = {(int)LOWORD(lParam),(int)HIWORD(lParam)};
          			g_pInterface->UpdateMouse(ptMouse, true);
          		}
          		break;
          		case WM_LBUTTONUP:
          		{
          			// get the position of the mouse
          			POINT ptMouse = {(int)LOWORD(lParam),(int)HIWORD(lParam)};
          			g_pInterface->UpdateMouse(ptMouse, false);
          		}
          		break;
          		case WM_MOUSEMOVE:
          		{
          			// get the position of the mouse
          			POINT ptMouse = {(int)LOWORD(lParam),(int)HIWORD(lParam)};
          			g_pInterface->UpdateMouse(ptMouse);
          
          			CString stMove;
          			stMove.Format("(%d,%d)",(int)LOWORD(lParam),(int)HIWORD(lParam));
          			//SetWindowText(g_hWND, stMove);
          		}
          		break;
          		case WM_DESTROY: 
          		{
          			// kill the application, this sends a WM_QUIT message 
          			PostQuitMessage(0);
          			// return success
          			return(0);
          		} 
          		break;
          		case WM_GRAPHNOTIFY:
          		{
          			g_pInterface->GetDirectShow()->OnGraphEvent();
          		}
          		break;
          		default:break;
          
          	} // end switch
          	// process any messages that we didn't take care of 
          	return (DefWindowProc(hWnd, msg, wParam, lParam));
          } // end WinProc
          

          And my main loop: (the message part)

          while(TRUE)
          {
          	// Get the time this function began executing
          	//DWORD dwStartTime = GetTickCount();
          	// test if there is a message in queue, if so get it
          	if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))
          	{ 
          		// test if this is a quit
          		if (msg.message == WM_QUIT)
          		   break;
          		// translate any accelerator keys
          		if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
          		{
          			TranslateMessage(&msg);
          			// send the message to the window proc
          			DispatchMessage(&msg);
          		}
          	} // end if
          /* Other processing... */
          }
          

          Dustin

          M 1 Reply Last reply
          0
          • J Johan Pretorius

            Something i forgot when you posted was that you wanted to pause the processing not lower it. try this if it does not work try send me an demo so i can test.

            //add global variable to main.cpp
            static bool g_bRunning = true;
            
            //Modify case statement
            case WM_ACTIVATE:
            {
               //See if we lost or gained focus
               if (LOWORD(wParam) == WA_ACTIVE)
               {
                 g_bRunning = true;
               }
               else
               {
                 g_bRunning = false;
               }
            }
            break;
            
            //add to main loop
            while (!g_bRunning){/*leave empty*/};//this should pause it.
            
            //just add an mutex and !!
            

            Artificial Intelligence is no match for Natural Stupidity
            No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
            I can't always be wrong ... or can I?

            D Offline
            D Offline
            Dustin Henry
            wrote on last edited by
            #7

            Since my message peek is in the main loop, if I do that it will no longer look for messages and will not tell me when focus has been restored.

            J 1 Reply Last reply
            0
            • M Mark Salsbery

              Dustin Henry wrote:

              I comment out all of my code in the loop except the windows message queue processing and my app jumps from 60fps to about 2000fps.

              What do you mean by "fps"? Typically a Windows message loop uses virtually no CPU until a message is received. What's going on in your message loop? Mark

              J Offline
              J Offline
              Johan Pretorius
              wrote on last edited by
              #8

              Mark Salsbery wrote:

              What do you mean by "fps"?

              Well i am guessing he is writing a game/game engine. Applications also lose focus when they are minimized. That is why he probaly needs the application to stop processing.


              Artificial Intelligence is no match for Natural Stupidity
              No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
              I can't always be wrong ... or can I?

              J 1 Reply Last reply
              0
              • D Dustin Henry

                Since my message peek is in the main loop, if I do that it will no longer look for messages and will not tell me when focus has been restored.

                J Offline
                J Offline
                Johan Pretorius
                wrote on last edited by
                #9

                Well you could put a copy of the messagepeek functions to the while (!m_bRunning) {}; then there should be no problems


                Artificial Intelligence is no match for Natural Stupidity
                No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
                I can't always be wrong ... or can I?

                1 Reply Last reply
                0
                • J Johan Pretorius

                  Mark Salsbery wrote:

                  What do you mean by "fps"?

                  Well i am guessing he is writing a game/game engine. Applications also lose focus when they are minimized. That is why he probaly needs the application to stop processing.


                  Artificial Intelligence is no match for Natural Stupidity
                  No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
                  I can't always be wrong ... or can I?

                  J Offline
                  J Offline
                  Johan Pretorius
                  wrote on last edited by
                  #10

                  Sorry his reply was not there when i posted mine


                  Artificial Intelligence is no match for Natural Stupidity
                  No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
                  I can't always be wrong ... or can I?

                  D 1 Reply Last reply
                  0
                  • J Johan Pretorius

                    Sorry his reply was not there when i posted mine


                    Artificial Intelligence is no match for Natural Stupidity
                    No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
                    I can't always be wrong ... or can I?

                    D Offline
                    D Offline
                    Dustin Henry
                    wrote on last edited by
                    #11

                    Well I think I fixed it. I basically used CaveFox's idea of a running boolean but in the main loop placed:

                    if (!g_bRunning)
                    	Sleep(1000);
                    

                    I believe this was happening because I allow the program to basically sit and spin in an infinite loop. Even if I commented out everything in the while(), the same thing happened. I guess the program just needed something to do. Any idea why this is? Thanks for your help guys. Dustin

                    M J 2 Replies Last reply
                    0
                    • D Dustin Henry

                      fps = Frames per second. It is a Direct3D application. Typically a Windows message loop uses virtually no CPU until a message is received I thought the same thing, but if I comment out all of my processing except for the message peek and dispatch, the app still eats the CPU when focus is lost. Here is my entire WindowProc:

                      LRESULT CALLBACK WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
                      {	 
                      	switch(msg)
                      	{	
                      		case WM_CREATE: 
                      		{  
                      			// do initialization stuff here
                      			// return success
                      			return(0);
                      		} 
                      		break;
                      		case WM_LBUTTONDOWN:
                      		{
                      			// get the position of the mouse
                      			POINT ptMouse = {(int)LOWORD(lParam),(int)HIWORD(lParam)};
                      			g_pInterface->UpdateMouse(ptMouse, true);
                      		}
                      		break;
                      		case WM_LBUTTONUP:
                      		{
                      			// get the position of the mouse
                      			POINT ptMouse = {(int)LOWORD(lParam),(int)HIWORD(lParam)};
                      			g_pInterface->UpdateMouse(ptMouse, false);
                      		}
                      		break;
                      		case WM_MOUSEMOVE:
                      		{
                      			// get the position of the mouse
                      			POINT ptMouse = {(int)LOWORD(lParam),(int)HIWORD(lParam)};
                      			g_pInterface->UpdateMouse(ptMouse);
                      
                      			CString stMove;
                      			stMove.Format("(%d,%d)",(int)LOWORD(lParam),(int)HIWORD(lParam));
                      			//SetWindowText(g_hWND, stMove);
                      		}
                      		break;
                      		case WM_DESTROY: 
                      		{
                      			// kill the application, this sends a WM_QUIT message 
                      			PostQuitMessage(0);
                      			// return success
                      			return(0);
                      		} 
                      		break;
                      		case WM_GRAPHNOTIFY:
                      		{
                      			g_pInterface->GetDirectShow()->OnGraphEvent();
                      		}
                      		break;
                      		default:break;
                      
                      	} // end switch
                      	// process any messages that we didn't take care of 
                      	return (DefWindowProc(hWnd, msg, wParam, lParam));
                      } // end WinProc
                      

                      And my main loop: (the message part)

                      while(TRUE)
                      {
                      	// Get the time this function began executing
                      	//DWORD dwStartTime = GetTickCount();
                      	// test if there is a message in queue, if so get it
                      	if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))
                      	{ 
                      		// test if this is a quit
                      		if (msg.message == WM_QUIT)
                      		   break;
                      		// translate any accelerator keys
                      		if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
                      		{
                      			TranslateMessage(&msg);
                      			// send the message to the window proc
                      			DispatchMessage(&msg);
                      		}
                      	} // end if
                      /* Other processing... */
                      }
                      

                      Dustin

                      M Offline
                      M Offline
                      Mark Salsbery
                      wrote on last edited by
                      #12

                      Try GetMessage instead of PeekMessage You shouldn't have to sleep or mess with thread priority for user interface thread :) Mark

                      1 Reply Last reply
                      0
                      • D Dustin Henry

                        Well I think I fixed it. I basically used CaveFox's idea of a running boolean but in the main loop placed:

                        if (!g_bRunning)
                        	Sleep(1000);
                        

                        I believe this was happening because I allow the program to basically sit and spin in an infinite loop. Even if I commented out everything in the while(), the same thing happened. I guess the program just needed something to do. Any idea why this is? Thanks for your help guys. Dustin

                        M Offline
                        M Offline
                        Mark Salsbery
                        wrote on last edited by
                        #13

                        No SLEEP()!!! ;)

                        while(GetMessage(&msg,NULL,0,0))
                        {
                        // translate any accelerator keys
                        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
                        {
                        TranslateMessage(&msg);
                        // send the message to the window proc
                        DispatchMessage(&msg);
                        }
                        }

                        1 Reply Last reply
                        0
                        • D Dustin Henry

                          Well I think I fixed it. I basically used CaveFox's idea of a running boolean but in the main loop placed:

                          if (!g_bRunning)
                          	Sleep(1000);
                          

                          I believe this was happening because I allow the program to basically sit and spin in an infinite loop. Even if I commented out everything in the while(), the same thing happened. I guess the program just needed something to do. Any idea why this is? Thanks for your help guys. Dustin

                          J Offline
                          J Offline
                          Johan Pretorius
                          wrote on last edited by
                          #14

                          This should stop all processing (except the messages).

                          case WM_ACTIVATE:
                          {
                             //See if we lost or gained focus
                             if (LOWORD(wParam) == WA_ACTIVE)
                             {
                               g_bRunning = true;
                             }
                             else
                             {
                               g_bRunning = false;
                             }
                          }
                          break;
                          
                          
                          static bool m_bRunning = true;
                          
                          while(TRUE)
                          {
                          	// Get the time this function began executing
                          	//DWORD dwStartTime = GetTickCount();
                          	// test if there is a message in queue, if so get it
                                  do
                                  {
                                       if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))
                                       { 
                          		// test if this is a quit
                          		if (msg.message == WM_QUIT)
                          		   break;
                          		// translate any accelerator keys
                          		if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
                          		{
                          			TranslateMessage(&msg);
                          			// send the message to the window proc
                          			DispatchMessage(&msg);
                          		}
                          	     } // end if
                                  } while(!m_bRunning)
                           /* Other processing... */
                          }
                          

                          Artificial Intelligence is no match for Natural Stupidity
                          No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
                          I can't always be wrong ... or can I?

                          1 Reply Last reply
                          0
                          • D Dustin Henry

                            I have an application with a main processing loop ( while(true){} ). When the application is running normally it eats up about 2% of the CPU. Whenever focus is taken away from the application window however, the CPU usage jumps to about 50%. This also happens when I comment out all of my code in the loop except the windows message queue processing and my app jumps from 60fps to about 2000fps. My question is, how do I 'pause' processing when focus is taken away, but still have the abilty to get window messages so I know when focus is given back? Thanks in advance, Dustin

                            M Offline
                            M Offline
                            Mark Salsbery
                            wrote on last edited by
                            #15

                            Really, I BEG you guys...pleeeease leave the poor UI thread alone :(( What did it ever do to you??? :)

                            J 1 Reply Last reply
                            0
                            • M Mark Salsbery

                              Really, I BEG you guys...pleeeease leave the poor UI thread alone :(( What did it ever do to you??? :)

                              J Offline
                              J Offline
                              Johan Pretorius
                              wrote on last edited by
                              #16

                              Yea it was a little overkill (by me X|) ... im sleep deprived and are not thinking strait. Should have solved it with the first post :^)


                              Artificial Intelligence is no match for Natural Stupidity
                              No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
                              I can't always be wrong ... or can I?

                              M 1 Reply Last reply
                              0
                              • J Johan Pretorius

                                Yea it was a little overkill (by me X|) ... im sleep deprived and are not thinking strait. Should have solved it with the first post :^)


                                Artificial Intelligence is no match for Natural Stupidity
                                No one can understand the truth until he drinks of coffee's frothy goodness. ~Sheik Abd-al-Kadir
                                I can't always be wrong ... or can I?

                                M Offline
                                M Offline
                                Mark Salsbery
                                wrote on last edited by
                                #17

                                :laugh: It looked right to me - I had to test it before I saw it! As soon as Sleep() comes up, it's time for an intervention :)

                                1 Reply Last reply
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