Failure To Properly Terminate Execution

[Wesley Brown]

Hello Everyone,

I occasionally receive the following error message:

Error 496 In Program.Bas(148:1): Destination File Write Error Line 148:End Function

When I get this error I can type "(ctrl)+(alt)+(del)" to bring up a list of programs that
are executing on my machine and I see 'Program.bas' on the list. What drives me crazy is
that the program terminates properly about 80% of the time (luck i guess) and that there
does not seem to be any reason as to when it does and does not terminate properly.

I have posted an abbreviated version of the code (but one that does contain the problem)
below and would appreciate any help to find the problem.

Thanks in Advance

Wesley

'Wesley Brown
'February 22, 2001

#Compile Exe
#Register None
#Dim All
#Include "WIN32API.INC"
'===========================================================================================
'Define Constants
$AppTitle           = "Program That Has Problems"
$ComPort            = "COM1"
%Exit               = 200  'Button, Exit Program
%Idt_Timer1         = 300  'Timer, Money & Volumn Update
%Idt_Timer2         = 301  'Timer, Screen Update
%MesgBox            = 400  'TextBox, Status Messages
'-------------------------------------
'Define Globals
Global hComm        As Long
Global hDlg         As Long
Global hListen      As Long
Global hLogic       As Long
Global LogicClose   As Long
Global ListenClose  As Long
Global Result       As Long
Global TtlBytes     As Long
Global BytesIn      As String
Global LBR          As String
'-------------------------------------
Function EndComms() As Long
   Dim dummy As String
   If Comm(#hComm, RxQue) Then Comm Recv #hComm, Comm(#hComm, RxQue), dummy
      Comm Close #hComm
End Function
'===========================================================================================
Function TxRxData(ByVal hWnd As Long) As Long
   While IsFalse ListenClose&
      While (IsFalse ListenClose&) And (LBR$ <> "x")
         If (IsFalse ListenClose&) And (Comm(#hComm, RxQue) = 0 ) Then Iterate Loop
         Comm Recv #hComm, 1, LBR$
         If LBR$ = Chr$(&H05) Then LBR$ = "x"
         BytesIn = LBR$
         TtlBytes = 1
         Wend
      While (IsFalse ListenClose&) And (LBR$ <> "z")
         If (IsFalse ListenClose&) And (Comm(#hComm, RxQue) = 0 ) Then Iterate Loop
         Comm Recv #hComm, 1, LBR$
         If (LBR$ = Chr$(&H17)) Then LBR$ = "y"
         If (LBR$ = Chr$(&H04)) Then LBR$ = "z"
         BytesIn = BytesIn & LBR$
         Incr TtlBytes
         Wend
      'Process BytesIn
      Wend
Function = %True
End Function
'===========================================================================================
Function StartComms As Long
  Comm Open $COMPORT As #hComm
  If ErrClear Then Exit Function          ' Exit if port cannot be opened
  Comm Set #hComm, Baud     = 9600        ' 9600 baud
  Comm Set #hComm, Byte     = 8           ' 8 bits
  Comm Set #hComm, Parity   = %False      ' No parity
  Comm Set #hComm, CtsFlow  = 0           ' Disable CTS Flow
  Comm Set #hComm, RtsFlow  = 0           ' Disable RTS Flow
  Comm Set #hComm, Xinpflow = 0           ' Disable Xon/Xoff on Input
  Comm Set #hComm, Stop     = 0           ' 1 stop bit
  Comm Set #hComm, TxBuffer = 4096        ' 4k transmit buffer
  Comm Set #hComm, RxBuffer = 4096        ' 4k receive buffer
  Function = %True
End Function
'===========================================================================================
'Dialog Control Callback Functions

'===========================================================================================
CallBack Function Dialog_Callback()
   Select Case CbMsg
          Case %Wm_Timer
             Select Case CbWparam
                    Case %Idt_Timer1
                         'Timer1 Routine
                    Case %Idt_Timer2
                         'Timer2 Routine
                End Select 'CbWparam
          Case %Wm_InitDialog
             SetTimer  hDlg, %Idt_Timer1, 100, ByVal %Null
             SetTimer  hDlg, %Idt_Timer2, 500, ByVal %Null
          Case %Wm_Destroy
             KillTimer hDlg, %Idt_Timer1
             KillTimer hDlg, %Idt_Timer2
      End Select 'CbMsg
   End Function

'===========================================================================================
CallBack Function Quit_Callback() As Long
    ' Kill the dialog and let PBMAIN() continue
    Dialog End hDlg, 0
End Function
'===========================================================================================
Function PbMain
  'Initialize Serial Port
  If IsFalse StartComms Then
        MsgBox "Failure to start communications!",, $AppTitle
        Exit Function
     End If
  'Create a Modal Dialog Box
  Dialog New 0, $AppTitle,,, 500, 380, %Ws_PopUp   Or %Ws_Visible Or %Ws_ClipChildren _
                     Or %Ws_Caption Or %Ws_SysMenu Or %Ws_MinimizeBox, 0 To hDlg
  Control Add Button,   hDlg, %Exit,        "Exit", 373, 350,  50,  14, Call Quit_Callback

'===========================================================================================

'Create A "Listen" Thread To Monitor Input From Serial Port
  Thread Create TxRxData(hDlg) To hListen

'Create "Logic" Thread (main program)
  Thread Create MainProg(hDlg) To hLogic

'Start the dialog box & run until DIALOG END executed.
  Dialog Show Modal hDlg,  Call Dialog_Callback To Result

'Close Down "Logic" Thread
  LogicClose& = %True
  Thread Suspend hLogic To Result
  Do
     Thread Close hLogic To Result
     Loop Until IsTrue Result

'Close Down "Listen" Thread
  ListenClose& = %True
  Thread Suspend hListen To Result
  Do
     Thread Close hListen To Result
     Loop Until IsTrue Result

' Flush & Close Comm Port
  Call EndComms
  Function = %True

End Function

'===========================================================================================

Function MainProg(ByVal hWnd As Long) As Long
  While IsFalse LogicClose&
        'Main Program Code
     Wend '(While IsFalse ThreadClose)
  Function = %True
End Function

------------------


[This message has been edited by Wesley Brown (edited February 22, 2001).]

[Steve Hutchesson]

Wesley,

I only ever get that error message when I try to compile a file
that is already running. Normally a disk file cannot be overwritten
if it is running.

This can be a problem if a program has crashed and is no longer
visible on the screen but still in memory. If this is the case
you will have to chase down what the problem is with the program
that prevents it from terminating.

Regards,

[email protected]

------------------

[Semen Matusovski]

I guess that Wesley works under Win9x.
Under Win2000 nothing happends "except" that CPU is busy 100%.

Wesley, once again --
following is able to kill any PC

   While (IsFalse ListenClose&) And (LBR$ <> "x")
      If (IsFalse ListenClose&) And (Comm(#hComm, RxQue) = 0 ) Then Iterate Loop

If nothing to do, you should give another tasks to work.
Change to

   While (IsFalse ListenClose&) And (LBR$ <> "x")
      If (IsFalse ListenClose&) And (Comm(#hComm, RxQue) = 0 ) Then Sleep 1: Iterate Loop

and look CPU usage.

[This message has been edited by Semen Matusovski (edited February 22, 2001).]

[Wesley Brown]

Thank you Semen. I have changed my code accordingly and appreciate your input. Furthermore,
I appreciate the patience that you (and others like you) show towards newbees such as myself.
I just hope that Lance never decides to put a "post limit" into place .

Wesley

------------------


[This message has been edited by Wesley Brown (edited February 22, 2001).]

[John Kovacich]

I see this message a lot. It almost always happens when I am trying to
compile a DLL, and had previously used the DLL from the Debugger.

If I execute my main exe in the Debugger, and the debugger intercepts a
crash, and I then close the debugger, I will get this message when I try to
re-compile any DLL's which were open at the time.

I have to exit the IDE and start over.

If I compile the DLL and EXE, then execute them externally to the IDE and
debugger, i do not get this message.


------------------
Thanks,

John Kovacich