[Orbit-python-list] ORBit - MICO

[Panagiotis I. <tak...@sk...>]

Hi,

I'm trying to set up a CORBA Component system. I've searched for Open
Source ORB's implementing at least a part of these standards and
stumbled upon MICO or actually MicoCCM. Luckily the clientside of a
CORBA system using components doesn't have to know about CORBA
components at all, so you can use any CORBA 2.3 (or 2.4?) compliant ORB
to use the components services. 

Because I like Python a lot, I wanted to use Python CORBA bindings and
because I've played around with Orbit-Python before, I decided to try
this one first. Half a year ago, I had lots of trouble getting _any_ ORB
to communicate with ORBit (omniORB, TAO, MICO). At this time, I still
didn't manage to get ORBit 0.x communicating with other ORBs but I'm
getting some good results with ORBit 2.5.0.


I'm using Debian GNU/Linux with orbit-python 1.99.0-4 on Python 2.2 with
ORBit version 2.5.0. I'm using MICO 2.3.7. The MICO C++ server works,
and also works with a MICO C++ client. The ORBit Python client works
partly.


When using a MICO server with an ORBit Python client, the operations get
invoked on the CORBA object (server), but the client application aborts
showing the following message:
** ERROR **: file orbit-object.c: line 146 (do_unref): assertion failed:
(robj->refs < ORBIT_REFCOUNT_MAX && robj->refs > 0)



On the MICO serverside:

pissaris@nyx:~/robot/cxx/a/b$ g++ main.o orocos.o orocos_impl.o -o blaai
-lmico2.3.7 -ldl orocos_skel.o 
pissaris@nyx:~/robot/cxx/a/b$ ./blaai 
found orb
found boa
a
Server reference:
IOR:010000001700000049444c3a4f726f636f732f4b756b613336313a312e300000020000000000000028000000010100000c0000003139322e3136382e302e3100ee8600000c000000424f41c0a8000100006789010100000024000000010000000100000001000000140000000100000001000100000000000901010000000000
echo STARTING KUKA
STOPPING KUKA
STARTING KUKA
STOPPING KUKA


As you can see, multiple invocations passed through (every invocation
causes one outputline of "STARTING KUKA","STOPPING KUKA"). The
serverside works just fine.

On the ORBit Python clientside:

pissaris@nyx:~/robot/cxx/a/b$ python takis.py 1
<Orocos.Kuka361 instance at 0x816888c>
Invoking operation on CORBA server
Ending CORBA client

** ERROR **: file orbit-object.c: line 146 (do_unref): assertion failed:
(robj->refs < ORBIT_REFCOUNT_MAX && robj->refs > 0)
aborting...
Afgebroken
pissaris@nyx:~/robot/cxx/a/b$ python takis.py 1
<Orocos.Kuka361 instance at 0x816888c>
Invoking operation on CORBA server
Ending CORBA client

** ERROR **: file orbit-object.c: line 146 (do_unref): assertion failed:
(robj->refs < ORBIT_REFCOUNT_MAX && robj->refs > 0)
aborting...
Afgebroken


Not directly related to the above:
When I use ORBit Python by itself (no MICO or anything else involved),
using void as return type causes an immediate segfault when using the
Python client:

pissaris@nyx:~/robot/cxx/a$ ./server 
found orb
found boa
a
Server reference:
IOR:010000001700000049444c3a4f726f636f732f4b756b613336313a312e300000020000000000000028000000010100000c0000003139322e3136382e302e3100248600000c000000424f41c0a800010000218b010100000024000000010000000100000001000000140000000100000001000100000000000901010000000000


STARTING KUKA
STARTING KUKA
STARTING KUKA
STARTING KUKA
STARTING KUKA

pissaris@nyx:~/robot/cxx/a$ python takis.py 1
<Orocos.Kuka361 instance at 0x8166864>
Invoking operation on CORBA server
Segmentatie fout


When using the old Python bindings of ORBit with the 0.x release of
ORBit, there's no communciation happening at all.

I'm going to try to write the client in C, using ORBit 2.5.0 and earlier
stable releases, to try to isolate the problem. But, if it is a known
problem, or if anyone has a solution, please tell me :-)

With friendly regards,
Takis