[omniORB] omniORBpy deadlock.

[Teemu Torma]

Python servant activation can lead to a deadlock in multi-threaded and 
embedded python / omniORB application.

The problem is that POA activate_object first takes omni::internalLock, 
and whilst holding it, calls python servant _add_ref(), which in turn 
takes omnipyThreadCache::lock (i.e., python interpreter lock).

The reverse sequence is also true in emebdded C++ code (we are using 
Boost.Python) where the C++ code does some CORBA object manipulation.  
Avoiding the python interpreter lock is slightly complicated and error 
prone in this situation, especially if one is using _var's to hold 
objects to make code exception safe.

The problem goes away by changing activate_object to call _add_ref() 
after omni::internalLock has been released.

Any ideas?

Teemu