Wait … to see !

[lp_irovetz]

Hi Advansys team,

I try to improve this piece of code

‘

---

Creation of a query = OK
qw.start

‘ Wait for the end of the Query
qwend = false
Do While not qwend
qwend = QW.Completed
if not qwend then
utilities.Timer(1)
end if
loop

Many time, i’d got errors with utilities.Timer(1). ( Memory violation, crash of GW, syntax error on these line ,…)

How to remplace it ? I’d like to wait until qw.completed but i don’t want to spend computer process power in the loop.

Any idea ?

L.P. Irovetz
Arcane GroupWare

Topic

[MA]

Use utilities.DoEvents() inside the loop to process any pending messages in Windows application message queue. If the query not completed after some waiting period then you may need to exit from the loop…

qwend = false
waitCounter = 0

‘ Wait for the end of the Query
Do While not qwend

‘ Exit after 30 seconds and issues a HALT to the GroupWise Search Engine
if (waitCounter > 30) then
QW.Stop()
utilities.doevents
exit do
end if

‘qwend = QW.Completed
if not qwend then
utilities.Timer(1)
waitCounter = waitCounter + 1
utilities.doevents
end if

loop

Thanks
MA

[Support 1a]

Thanks MA.

My experience with Object API Queries has been that they sometimes never return. I haven’t used one in some time, so Novell may have improved them since I last tried. We tend to use Find() instead of queries for this reason.

Advansys Support

[lp_irovetz]

Sorry but the problem is not in Query process but with utilities.Timer()

Thanks MA. “utilities.doevent” seems to help query to search asynchronously but problem persist.
Thanks Support. But how used “find” with documents ?

The problem is more present with low connection between clien and PO.
In local mode, nearly no problems
With low connection (even 1Mo SDSL mode), the only way is to increase time
– Using utilities.Timer(2) rather utilities.Timer(1) – but we don’t stop crashs

Is there a way to work around “utilities.Timer” ?

Thanks

L.P.

[Support 1a]

Utilities.Timer() using a Windows Timer object, which puts the thread from which it is called to ‘sleep’ for the specified time. Formativ runs in the same thread as the GroupWise client, so using a timer will also put GroupWise to sleep. (The GroupWise Query runs in it’s own thread). I suspect the errors you are seeing are a result of a threading/timing issue resulting from putting the main GroupWise thread to sleep while the query thread is running.

One solution (in theory) would be to run the query in a different thread and wait for it to return. You can’t do this in Formativ, but you could do it with a 4GL like VB, Delphi, C++, etc. However, Novell’s Object API documumentation indicates that free-threading (the ability to use any object created on any thread from any other thread) is not recommended. Our experience is that it should not be attempted at all. This means you can’t use a multi-threaded approach to solving this type of problem.

Unfortunately the only approach I can think of would be to not use a timer, and simply sit in a loop calling Utilities.DoEvents() to ensure the Windows message queue is processed while the query is being executed.

You may be able to obtain more information about using the Object API Find() and Query() objects from Novell, either directly or via the Developer forums they host.

Regards,

Advansys Support

[Author]

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