[prev in list] [next in list] [prev in thread] [next in thread] 

List:       kde-devel
Subject:    Re: Execution replay for Qt/KDE applications
From:       Benjamin Meyer <ben () meyerhome ! net>
Date:       2004-10-18 2:48:39
Message-ID: 200410172248.42044.ben () meyerhome ! net
[Download RAW message or body]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Sunday 17 October 2004 11:10 am, Oliver Oppitz wrote:
> >> cool. I really interested in this kind of possibility. Maybe this can
> >> be merged into Qt in the future?
>
> Most of the project does not need modifications to Qt itself, its just
> additional classes. However, to get a _guaranteed_ correct replay, minimal
> changes to the Qt eventLoop are necessary. This is to synchronize the
> QEvents I post during the replay with the call graph like it was during
> the execution: e.g. the events handled in the say 42nd invocation of the
> Qt eventLoop during the execution phase, need to be handled in the 42nd
> invocation in the replay phase. For most applications this does not
> matter: it is irrelevant how fast you type, so we replay events with
> roughly the same timing. Indeed this synchronisation _should_ never
> matter, otherwise you have a bad design if your application depends on it.
>
> However, for debugging we want to have _identical_ behaviour as in the
> original run. I have an editor that works nicely, but once I open some 25
> (!) windows (showing the same buffer) and insert characters via keyrepeat
> ("fast") the cursor misses to advance its position now and then. This is
> clearly some timing/reentrancy problem due to the massive slow down of the
> 25 windows (my X-server is a lightning-fast 600 Mhz Via C3 machine: slow
> machines do have advantages ;-). For debugging this a recording/replay
> tool would be _really_ handy: the events are recorded in _real time_ but
> they can be replayed in _non real time_ (assuming the little fix to the Qt
> event loop). You can then even set break points during the replay. Is that
> neat or what? ;-)
>
> >> What about setting up a project in the SF?
>
> I will make it public within the week, though it is really early.
> Currently it only captures keystrokes.
>
> > Or just putting it in kdenonbeta
>
> I do not know about kdennonbeta yet. I need to check this out.

kdenonbeta is a cvs module in kde that is used for developers who want to just 
play around and try stuff out.  If/When it becomes mature it is moved to 
kdesdk or some released module.

- -Benjamin Meyer

- -- 
aka icefox
Public Key: http://www.csh.rit.edu/~benjamin/public_key.asc
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)

iD8DBQFBcy8H1rZ3LTw38vIRAm1yAJwI+yDcZYteJNuT7jfOpWueSuQdgACgrQ4T
qaUHbm/SxwS+qQCgRF8A+6k=
=U0JV
-----END PGP SIGNATURE-----
 
>> Visit http://mail.kde.org/mailman/listinfo/kde-devel#unsub to unsubscribe <<
[prev in list] [next in list] [prev in thread] [next in thread]