8 replies to this topic

[guinness]

This is slightly different to how _Singleton (Misc.au3) works by Valik, because firstly this function uses the hidden window of an AutoIt executable and secondly it returns the PID of the main executable, not the handle to the object used for synchronization. It should also be noted that $iFlag parameter 2 doesn't exist in this function and if no program exists already _SingletonPID returns 0. Any suggestions are welcome. Thanks.

Function:

AutoIt        expandcollapse  popup

; #FUNCTION# ====================================================================================================================
; Name ..........: _SingletonPID
; Description ...: Enforce a design paradigm where only one instance of the script may be running.
; Syntax ........: _SingletonPID($sOccurenceName[, $iFlag = 0])
; Parameters ....: $sOccurenceName      - String to identify the occurrence of the script.
;                  $iFlag               - [optional] Optional parameters. Default is 0.
;                   0 - Exit the script with the exit code -1 if another instance already exists.
;                   1 - Return the PID of the main executable and without exiting the script too.
; Return values .: Success - 0 No other process is running.
;                  Failure - The PID of the main executable.
; Author ........: guinness with initial ideas by Valik for _Singleton & KaFu for _EnforceSingleInstance.
; Example .......: Yes
; ===============================================================================================================================
Func _SingletonPID($sOccurenceName, $iFlag = 0)
    Local $hWnd = WinGetHandle($sOccurenceName)
    If @error Then
        AutoItWinSetTitle($sOccurenceName)
        $hWnd = WinGetHandle($sOccurenceName)
        ControlSetText($hWnd, '', ControlGetHandle($hWnd, '', 'Edit1'), @AutoItPID)
    Else
        If BitAND($iFlag, 1) Then
            Return Number(ControlGetText($hWnd, '', ControlGetHandle($hWnd, '', 'Edit1')))
        Else
            Exit -1
        EndIf
    EndIf
    Return 0
EndFunc   ;==>_SingletonPID

Example 1:

Local $iSingleton = _SingletonPID('myUniqueName', 1)

If $iSingleton = 0 Then
    MsgBox(4096, '', 'This is the first instance of the program running: ' & $iSingleton)
Else
    MsgBox(4096, '', 'There is another instance running. This PID is: ' & $iSingleton)
EndIf

Example 2:

Local $iSingleton = _SingletonPID('myUniqueName', 1)

If $iSingleton = 0 Then
    MsgBox(4096, '', 'This is the first instance of the program running: ' & $iSingleton)
Else
    MsgBox(4096, '', 'There is another instance running. This PID is: ' & $iSingleton)

    ; Wait for the process to close.
    ProcessWaitClose($iSingleton, 5)

    ; Reset _SingletonPID to current process since the previous one was closed.
    $iSingleton = _SingletonPID('myUniqueName', 1)
    MsgBox(4096, '', 'This is now the first instance of the program running: ' & $iSingleton)
EndIf

Edited by guinness, 18 October 2012 - 01:32 PM.

[qvex21]

Great. I am just writing my first script in a productive environment and already needed a way to prevent multiple instances of the script, but not by preventing further intances from executing but by killing the older instances. So your 2 weeks old function just comes just at the right time for me.

dim $iScriptIsRunnig = _SingletonPID( "HWS-start-stop.exe", 1)
If $iScriptIsRunnig Then ProcessClose( $iScriptIsRunnig)

Thanks a lot.

[guinness]

Great, didn't think anyone would use it. One point to make with your code is don't use Dim, try to use Global (if necessary) or Local scope.

[qvex21]

Great, didn't think anyone would use it.

And i didn't think that my problem would be solved so quickly.

One point to make with your code is don't use Dim, try to use Global (if necessary) or Local scope.

Thanks for the hint.

[qvex21]

Local $iScriptIsRunnig = _SingletonPID( "HWS-start-stop.exe", 1)
If $iScriptIsRunnig Then ProcessWaitClose( $iScriptIsRunnig)
; some code

MMh... When i execute my compiled script, it runs (ok). When i execute it again while the first instance is still running, it kills the older instance and runs (ok). Now only the new instance is running (looked up that in process explorer). But when i execute it again the third time, it doesn't kill the other instance any more.

Edited by qvex21, 14 May 2012 - 09:43 PM.

[guinness]

There is no bug, everything is working correctly, basically you need to reset _SingletonPID to the new process e.g.

Local $iSingleton = _SingletonPID('RandomName', 1)

If $iSingleton = 0 Then
    MsgBox(4096, '', 'This is the first instance of the program running: ' & $iSingleton)
Else
    MsgBox(4096, '', 'There is another instance running. This PID is: ' & $iSingleton)

    ; Wait for the process to close.
    ProcessWaitClose($iSingleton, 5)

    ; Reset _SingletonPID to current process since the previous one was closed.
    $iSingleton = _SingletonPID('RandomName', 1)
    MsgBox(4096, '', 'This is now the first instance of the program running: ' & $iSingleton)
EndIf

[qvex21]

There is no bug, everything is working correctly, basically you need to reset _SingletonPID to the new process e.g.

I thought that, when only the second instance is running and i start the third, the first line of my code should do the reset. Maybe i unterstand that later, i am just a beginner. Anyway, meanwhile i solved my problem this way:

$aProcList = ProcessList ( "HWS-start-stop.exe" )
For $i = 1 To $aProcList[0][0]
    If $aProcList[$i][1] <> @AutoItPID Then ProcessClose($aProcList[$i][1])
Next 

Edited by qvex21, 15 May 2012 - 07:40 PM.

[guinness]

I'm not following, what I provided you works.

Edit: Ah, I think you misunderstood the purpose of this function from what you posted.

Edited by guinness, 15 May 2012 - 07:41 PM.

[guinness]

Updated the function syntax and added a second example on how to close the PID and reset to the current process.