#1 KDE Runtime Observer report

[David Moreno Montero]

Hi,

Just a few lines to tell you all how is the KDE runtime observer going.

Please send me any feedback you have: if you try the program and crashes 
watching X application, if you dont like the colors, if you have any 
suggestion...


KDE Runtime Observed is amied to get a full runtime observer of KDE 
applications at runtime, showing information about containment of 
objects, signals and slots, and some information when that is emmited. 
All without any change, or recompilation nor anything to the observed 
application.

First of all it is working and it actually can show you a (limited) tree 
with all your objects of any Qt/KDE application, with no big slowdown. 
I've prepared a tarball and a debian package at 
http://www.monasteriomono.org/programs/kro/

This last weeks I've been working on two fronts. First of all I did a 
shared library that overrides all the QObject methods from libqt (that 
might be a maintenance problem in the future, but the changes were small 
enoght to be repeteable very easily). That library works preloading it 
and then loading the application (LD_PRELOAD=/usr/lib/libkrol.so 
/usr/bin/konqueror), then a pipe is created at /tmp/ (or $TEMP, and 
after opening it (cat /tmp/krop-$(pid)) lot of information is dumped there.

Then I made a GUI that just now is only able to show you a limited tree 
view of the running process. The view is limited so it can only show an 
open branch and actually it is not implemented to unpack grouped 
objects. Objects are grouped by class and level. If you watch the 
screenshots you will see hundreds of QObject's packed in one single box, 
for example. If you try to open that branch, the first object will be 
opened.

I also looked on how to catch correctly the signals/slots and looked on 
a gdb based aproach, and maybe i will take that idea later, but it 
looked so complicated by the moment.

The biggest problems I found are just two (maybe too technical and 
specific for this project): First when I catch the QObject creation, and 
send the class type, that class type is always QObject, independant of 
the real class. className() method on any QObject should return the 
class name, but that is not true at that moment. That forced me to do a 
hack and send the class name at other moments (signal connection), and 
have impact over performance of observed application.

The seccond one is that I'm not 100% percent sure of catching 
everything. My worst worry is about catching all signals, but I guess 
I'll have to fight against it later.


Overall I think that about 30% of the project is done, but the hardest 
is to come: all the signals stuff. Anyway all my friends are going on 
holidays, and I'm staying here (Madrid, Spain, to study and work), so I 
will have lot of time to use here.


Thank you.