two major problems in VB4 
Author Message
 two major problems in VB4


Our environment is:  WFW3.11, VB4, DOS 6.22 running on 486DX100s, 16mb
400+mb free disk space, 800x600 SVGA, 65kcolor.

We have an application that consists of a main GUI for the users (EAMS)
and three background processes (Scheduler, Manager and Interface).  EAMS
starts all three applications and communicates with them via class

FIRST Problem:

If either Scheduler or Interface crashes, it will immediately cause the
other to crash, then Manager crashes, then EAMS hangs with an OLE
Automation Error and we have to reboot.  This happens consistently and
always in this order.  Scheduler, Manager and Interface do not
communicate with each other, only with EAMS.  The GPFs almost always
occurs in  DAO2516, although we have seen occasional other modules named
as the culprit.

From reading the manuals, it appears that each module opens it's own
copy of DAO2516 (ie, non-reentrant).  Why should a blowout in one cause
immediate, similar blowouts in the others?

We have a similar problem when running the modules in VB mode for
debugging.  When we terminate all processes and close VB (it doesn't
matter which one we close first), it almost always gives a GPF in VBA2
and sure enough, so will all the others.  If the first one does not
error out, the others won't, either.

SECOND Problem:

The following chunk of code exists in a timer routine that executes
three seconds.  It has run with no hitches at all until we did like
Microsoft suggested and added DbEngine.Idle DbFreeLocks after all seeks,
finds, and recordset opens.  Now it runs until we complete a packaging
sequence, at which time the marked line gives an error of Invalid
Database Object.  At no point in the code is the database (SDB) changed
in any way.  We open it in Sub Main when the app starts and close it
when a shutdown message is received from EAMS.  Once we remove the Idle
statements, everything works OK.

        If DatabasesOpen Then
' refresh sysfile to see if any changes were made
            Set DsSysFile = SDB.OpenRecordset("select * from Sysfile",
 ' get the max number of envelopes per medtote
            'If DsSysFile!Envfilled = 0 Then
            If Not gbEnvPerPat Then
            ' one order per envelope
                    MaxEnvs = DsSysFile!MaxEnvsIfMed   <==== ERROR
                    MaxEnvs = DsSysFile!MaxEnvsIfPat
                End If
            End If
' get max pills per envelope and maxorders per envelope in case they
' changed as well
            MaxOrdersPerEnvelope = DsSysFile!maxordersenv
            MaxPillsPerEnvelope = DsSysFile!maxpillsenv
' if we are waiting on a dump cartridge command, look to see if
' is needed.  if not, do the dump, otherwise exit
           If DsSysFile!needtodumpcartridges Then
                 If DsSysFile!NeedAuthorization Then
                     frmManager.Caption = AppName & " - Waiting for
                     If RunInProgress And Not PauseInProgress Then
                          PauseInProgress = True

                          SelectedRunId = CurrentRunId
                          Call UpdateDisplay("Pausing")
                          cmdPause.Caption = "&Resume"
                          cmdPause.Enabled = False
                        End If
                     Exit Sub
                     Call LookForZeroContainers
                     On Error GoTo syserror
                     If StartUp And Successful Then
                       DsSysFile.LockEdits = True
                       DsSysFile!needtodumpcartridges = False
                       DsSysFile.LockEdits = False
                       On Error GoTo 0
                       frmManager.Caption = AppName
                     End If
                End If
        End If

We're very frustrated, as you might imagine.  Has anyone had similar
and, if so, what did you do to get around them?

Thanks in advance!

Thu, 16 Dec 1999 03:00:00 GMT  
 [ 1 post ] 

 Relevant Pages 

1. Two Major Questions

2. Two VB3/VB4 Problems

3. Two VB4 Problems: Forms and Math

4. ADO Update problems MAJOR PROBLEMS !!


6. Major Help needed with VB4 + Windows 3.11 Linked to Access 2.0 on Novell 4

7. VB4 - Major Bug or what?

8. VB4 Professional and Enterprise - Major Differences ??

9. MAJOR problem with code on a form

10. Tab Controls - Please help !!!! Major problem

11. A major problem with ParamArray in VB.NET

12. Major problem w/ datagrid


Powered by phpBB® Forum Software