[Oberon] Message queue and Pointer

Dan Parnete dan.parnete at fastwebnet.it
Wed May 10 12:41:18 CEST 2006


    As exposed in a previous issue "Bluebottle limits reached" we have 
grow the message queue size. This solved the lose of messages, but in a 
particular situation it puts in evidence a big number of useless 
messages that arrives to subcomponents, spending to much processor time.
    To observe this you need to use the framework, or better an 
application I use for test and development. It is more evident using a 
Windows client, witch is slower a has the message queue enlarged, the in 
Bluebottle witch is faster and with it's 128 queue discard 
(providentially) most of the useless messages. You have to download the 
BBwClient from and extract it somewhere. Execute 
Aos.exe and at the login window write:
    Database: DanDb
    User: public
    Password: user
At the first time a modules upgrade will be done, and then exits. You 
have to reenter. Then go to Setup/Admin to enter the IDE (development 
system). Here pressing ctrl-o will open the Kernel Log. Then open 
FORMS/Clienti for example. Make a multi selection with ML and drag over 
some fields. Then ML a selected one and drag around to move them. 
Release the mouse and then click somewhere on the form, out of the any 
field. Repeat that click until selected fields are unselected.
You can move selected fields not only by mouse drag (5 pixel grid step) 
but even with the arrow keys (1 pixel).

1. During this moving operation a lot of messages are fired. It depends 
on the number of fields selected. If all useful messages are executed in 
reasonable time, what kind of messages are still on the queue and create 
this latency?
2. What happens with the pointer massages during this latency? As you 
can see on the log, even if the mouse points on the form, the control 
witch receive the PointerDown is a label/field (Label PD), and finally 
when all message queues have finished their activities, the form 
receives it (Form PD). Very strange. Haw could be explained?

P.S.: If you will see a "User or password unknown" during the use of the 
application, means another connection with the same user has been done 
after you. Only one connection with a user name is admitted.

Thank you,
Dan Parnete

More information about the Oberon mailing list