Issue 5895: Problem with ServerRequestInterceptor::receive_request and DSI (corba-rtf)
Source: Floorboard Software (Mr. Jonathan Biggar, jon(at)floorboard.com)
Nature: Uncategorized Issue
Severity: 
Summary: 21.3.9.2 states:


"In the DSI model, since the parameters are first available when the user code calls arguments, receive_request is called from within arguments. It is possible that arguments is not called in the DSI model. The target may call set_exception before calling arguments. The ORB shall guarantee that receive_request is called once, either through arguments or through set_exception."


The problem here, is that the DSI servant has already been invoked at this point, and the DSI implementation will be unaware that the server interceptor may have cancelled the invocation via raising a system exception or ForwardRequest user exception.  So the DSI implementation will carry on, creating all sorts of wonderful havoc as it continues to interact with the ServerRequest PO.


Any vendors want to comment on what their PI implementation does now?


Proposed fix:


First, we should define a new system exception minor code that the servant implementation can detect so that it can clean up and get out of the way as expeditiously as possible when raised by arguments or set_exception. Perhaps a minor code for OBJ_ADAPTER? Should there be two minor codes, to distinguish a system exception from ForwardRequest as the reason for cancelling the invocation?


Second, we need some more text either in chapter 8 or 21 that states that any calls by the DSI implementation to ServerRequest::set_result or ServerRequest::set_exception will be ignored (or perhaps reraise the exception defined in the previous paragraph) if ServerRequestInterceptor::receive_request raises an exception.

Resolution: 
Revised Text: 
Actions taken:
April 2, 2003: received issue
April 11, 2012: Deferred
Discussion: 

End of Annotations:=====
Date: Wed, 02 Apr 2003 13:36:39 -0800 
From: Jonathan Biggar <jon@floorboard.com> 
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To: corba-rtf@omg.org 
Subject: Problem with ServerRequestInterceptor::receive_request and DSI 


21.3.9.2 states:


"In the DSI model, since the parameters are first available when the user code calls arguments, receive_request is called from within arguments. It is possible that arguments is not called in the DSI model. The target may call set_exception before calling arguments. The ORB shall guarantee that receive_request is called once, either through arguments or through set_exception."


The problem here, is that the DSI servant has already been invoked at this point, and the DSI implementation will be unaware that the server interceptor may have cancelled the invocation via raising a system exception or ForwardRequest user exception.  So the DSI implementation will carry on, creating all sorts of wonderful havoc as it continues to interact with the ServerRequest PO.


Any vendors want to comment on what their PI implementation does now?


Proposed fix:


First, we should define a new system exception minor code that the servant implementation can detect so that it can clean up and get out of the way as expeditiously as possible when raised by arguments or set_exception. Perhaps a minor code for OBJ_ADAPTER? Should there be two minor codes, to distinguish a system exception from ForwardRequest as the reason for cancelling the invocation?


Second, we need some more text either in chapter 8 or 21 that states that any calls by the DSI implementation to ServerRequest::set_result or ServerRequest::set_exception will be ignored (or perhaps reraise the exception defined in the previous paragraph) if ServerRequestInterceptor::receive_request raises an exception.


-- 
Jon Biggar
Floorboard Software
jon@floorboard.com
jon@biggar.org