[orbitcpp-list] passing a reference to another process

[<MHL...@t-...>]

On Son, 19 Nov 2000 00:08:36 Martin Schulze wrote:
Hi,

I ran into some troubles implementing a signal-slot-technology
with CORBA-objects:


Given three processes pA, pB, pC.
Is it possible to pass a reference retrieved in process pC from
the IOR referring to an object in the address space of pB
to process pA directly ?



In details:

Let's say I have interfaces iA, iAA, iB, iBB.
class iA_impl contains a class iAA_impl (= oAA),
class iB_impl contains a calss iBB_impl (= oBB).

Now I have two processes running, pA and pB.
pA has an iA_impl on the heap (= oA), pB an iB_impl (= oB).

A third process pC is created, retrieving refences to oA and oB
through their IORs. A function of iA is called, returning a
reference to oAA and a function of iB gives a reference to oBB.
Now a function of iAA is called, giving the REFERENCE to oBB
AS its ARGUMENT.

Another function of oAA is called. It implicitely calls a function
of oBB - so process pA uses the reference of oBB that was
retrieved in process pC.

=> A SEGFAULT in pA occurs in the function _orb_get_connection
called by the skel of the very last function call mentioned obove.
=> Bug in orbit or my design error ???



In ASCII:
___________________________________________________________________

Process:	pA				pB					pC
		=======			=======				=======
Heap:		oA   <-----		oB   <-----
		-oAA <--  |		-oBB <--  |
		       |  |		       |  |
Refs:		       |  |		       |  --(IOR)-- rB
		       |  |		       --(rB->f())- rBB <--
		       |  |							      |
		       |  -----------(IOR)--------- rA    |
		       -----------(rA->f1())------- rAA   |
											      |
		-rBB -------------(rA->f2(rBB))------------

(xx->fx(): function calls invoked in pC for retrieving the references)

In pA: oA.rBB->callback() segfaults !

______________________________________________________________________



Sorry for this being a little long!

cu Martin.