> How is it possible to determine a process is "not responding" like NT Task > Manager do? The heuristic works only for GUI processes, and consists of calling SendMessageTimeOut() with SMTO_ABORTIFHUNG.
>There is any API call to do the job, or this status is simply a deduction >based on process counters, like that returned from call to GetProcessTimes >API function?
Use SendMessageTimeout with a value of WM_NULL. That‘s all Task Manager does to determine this AFAIK.
-- 有理有理.当然,我这里还有一个UNDOCUMENTED函数,乃是其他的解决方案,NT和9X有个USER32.DLL的函数,IsHungAppWindow(NT)和IsHungThread(9X).使用起来简便无比.下面给出原型. BOOL IsHungAppWindow ( HWND hWnd, // handle to main app‘s window );
BOOL IsHungThread ( DWORD dwThreadId, // The thread‘s identifier of the main app‘s window ); 有了原型,连解释都不需要,好得不的了.:)不过调用时需要GetProcAddress.库里没有该函数. **************************************** check whether an application (window) is not responding?
{1. The Documented way}
{ An application can check if a window is responding to messages by sending the WM_NULL message with the SendMessageTimeout function. }
function AppIsResponding(ClassName: string): Boolean; const { Specifies the duration, in milliseconds, of the time-out period } TIMEOUT = 50; var Res: DWORD; h: HWND; begin h := FindWindow(PChar(ClassName), nil); if h <> 0 then Result := SendMessageTimeOut(H, WM_NULL, 0, 0, SMTO_NORMAL or SMTO_ABORTIFHUNG, TIMEOUT, Res) <> 0 else ShowMessage(Format(‘%s not found!‘, [ClassName])); end;
procedure TForm1.Button1Click(Sender: TObject); begin if AppIsResponding(‘OpusApp‘) then { OpusApp is the Class Name of WINWORD.EXE } ShowMessage(‘App. responding‘); end;
{2. The Undocumented way}
{ // Translated form C to Delphi by Thomas Stutz // Original Code: // (c)1999 Ashot Oganesyan K, SmartLine, Inc // mailto:ashot@aha.ru, http://www.protect-me.com, http://www.codepile.com
The code doesn‘t use the Win32 API SendMessageTimout function to determine if the target application is responding but calls undocumented functions from the User32.dll.
--> For Windows 95/98/ME we call the IsHungThread() API
The function IsHungAppWindow retrieves the status (running or not responding) of the specified application
IsHungAppWindow(Wnd: HWND): // handle to main app‘s window BOOL;
--> For NT/2000/XP the IsHungAppWindow() API:
The function IsHungThread retrieves the status (running or not responding) of the specified thread
IsHungThread(DWORD dwThreadId): // The thread‘s identifier of the main app‘s window BOOL;
Unfortunately, Microsoft doesn‘t provide us with the exports symbols in the User32.lib for these functions, so we should load them dynamically using the GetModuleHandle and GetProcAddress functions: }
// For Win9X/ME function IsAppRespondig9X(dwThreadId: DWORD): Boolean; type TIsHungThread = function(dwThreadId: DWORD): BOOL; stdcall; var hUser32: THandle; IsHungThread: TIsHungThread; begin Result := True; hUser32 := GetModuleHandle(‘user32.dll‘); if (hUser32 > 0) then begin @IsHungThread := GetProcAddress(hUser32, ‘IsHungThread‘); if Assigned(IsHungThread) then begin Result := not IsHungThread(dwThreadId); end; end; end;
// For Win NT/2000/XP function IsAppRespondigNT(wnd: HWND): Boolean; type TIsHungAppWindow = function(wnd:hWnd): BOOL; stdcall; var hUser32: THandle; IsHungAppWindow: TIsHungAppWindow; begin Result := True; hUser32 := GetModuleHandle(‘user32.dll‘); if (hUser32 > 0) then begin @IsHungAppWindow := GetProcAddress(hUser32, ‘IsHungAppWindow‘); if Assigned(IsHungAppWindow) then begin Result := not IsHungAppWindow(wnd); end; end; end;
function IsAppRespondig(Wnd: HWND): Boolean; begin if not IsWindow(Wnd) then begin ShowMessage(‘Incorrect window handle!‘); Exit; end; if Win32Platform = VER_PLATFORM_WIN32_NT then Result := IsAppRespondigNT(wnd) else Result := IsAppRespondig9X(GetWindowThreadProcessId(Wnd,nil)); end;
// Example: Check if Word is hung/responding
procedure TForm1.Button3Click(Sender: TObject); var Res: DWORD; h: HWND; begin // Find Word by classname h := FindWindow(PChar(‘OpusApp‘), nil); if h <> 0 then begin if IsAppRespondig(h) then ShowMessage(‘Word is responding!‘) else ShowMessage(‘Word is not responding!‘); end else ShowMessage(‘Word is not open!‘); end;
