Re: [simspark-devel] Countdown for Atlanta

[Yuan X. <xuy...@gm...>]

Hi Joschka,


>
> First, a quick comment on the patch: I noticed that probably an older
> version of sceneserver.cpp was used, as the patch removes some recent
> code in SceneServer::ImportScene (namely searching for data files in the
> local dir _and_ in the pkgdatadir).

Sorry, I worked on 0.5.4 package,and then make the patch manually,
and missed the new sceneserver.
The modifies are not conflict.


> Another problem that I had was that sometimes (not often, and
> non-deterministically), the InitEffector will cause the Server to crash
> with an ODE internal error (error message something like "dGeom was
> moved in locked space"). I have never seen this with the non-threaded
> version so far, so maybe we need a lock somewhere in the InitEffector,
> too (because it changes the Scene and uses ODE functions).

I checked the InitEffector, it calls ODE functions in Realize method
But I notice that almost every Effector's Realize methods call ODE functions,
it seems that the server doesn't work safely.
However, I only face such problem while agent connected or disconnected.
So, *maybe* calling ODE function is OK, but other methods in
connect/disconnect need be locked.

> On an Apple Mac I got some other problems, too, that did not occur in Linux:
>
> * I can not use any visualization because OpenGL is not thread-safe in
> MacOS. It seems that maybe two different threads are trying to issue
> OpenGL commands which does not work with Apple's GL implementation
> (threads can be used, but only if all the OpenGL commands for a context
> are issued in the same thread).
>
> * Ruby (version 1.8.2) would sometimes get a stack exception when I
> started several agents (over the network, only the server was running on
> the Mac).

I can only work in Linux. Maybe newer version library can solve them.
Will only the Linux be used in Atlanta? or multi-system, such as
windows and MacOS ?

> Concerning the development in the CVS, I think we will first merge the
> projectx branch that Oliver created with the main branch, and then we
> make a new branch for the threaded version. Do you have any idea about
> the input problems mentioned above?
>

What about my proposal about restrict the joint angle range?


-- 
Best wishes!

Xu Yuan
School of Automation
Southeast University, Nanjing, China

mail:   xuy...@gm...
          xy...@ya...
web:   http://xuyuan.cn.googlepages.com
--------------------------------------------------