Re: Bug in demos/Clock

[Tim Teulings <tim@edge.ping.de>]

Hallo!

> Last week I downloaded the latest Version of VO, X, and oo2c.
> I wasn't able to compile with the garbagecollector, but I think
> this should not be the reason for the problem I have with
> demos/Clock. It was compiled without errors, but it always

If you don´t have a gc no memory will be freed while your program is
running. This may cause out of memory errors while compiling oo2c or
the VO shared library (since all modules will be compiled in one run).
Also VO programs tend to allocate a lot of memory while running (event
handling etc.. are handled by objects, I´m currently not sure if VO
reuses global instances (it does at some places) in all such cases).

> leads to a segmentation fault.

There should be nothing special about Clock. Does the digital version
(DigiClock work?). Does Clock crash immediately or does it take some
time?

> The following shows some information from gdb.
> After #4 there is a msg <Error reading address 0x80019a:
> Operation not permitted>. I guess this causes my problem,
> but I don't know what it really means. Can anyone help?

The problem seems to be within VOText (a powerfull text object, which
supports multiline text including various formating styles and which is
used for nearly all text within the demos). VOText is used to display the
current time (and on left mouseclick the current date) under the analog
clock in Clock. I have seen this kind of crash but currently do not
remember what kind of bug causes it. I crosschecked VOText in the past
several times, and I doubt that there is a *obvious* bug within it.

I would suggest to add some debugging code (in form of Err.String etc.)
within VOText to check it functionality. Exspecially instrument SetText
to see, if the text assigned to it makes any sense (e.g. a valid date).
The buggy code gets called from SetText (NewLine, NewTextPart and
ClosePart is the execution path) so perhaps there *is* a bug, but I
thing Clock.Draw is more likely buggy. PLease check the time/date string
and its conversion for correctness...

I´m sorry that I can´t give your more help, but I cannot reproduce the
bug and havn´t heard of a similar problem. I hope that your debbugging
session might give me further hints and hope that you find the time to
check the named things for me.

Btw., I´m running VO under RedHat 5.2 (Intel version) using 1.3.12 (not
the last version, but I´m currently doing a removal (hope that is the
correct word for it ;-)) and I´m also having a unoffical timeout from
VO).

Of course I will try to give your more help if you will not be able to
find the bug. You mail (use the list, please, it is so silent here).

--
Gruß...
       Tim.

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