Re: [sca-c-cpp] NEW ISSUE: AllowsPassByReference requires more detaileddescription

[Andrew Borley <BORLEY@uk.ibm.com>]

This issue has been assigned ID CCPP-59
by the Jira system
See http://www.osoa.org/jira/browse/CCPP-59

Andrew

____________________________________________________________

Andrew Borley
Websphere ESB Development
Tel: 245393 Ext: +44 (0) 1962 815393 Mob: +44 (0) 7971 805547
E-mail: borley@uk.ibm.com
Mailpoint 211, IBM (UK) Ltd, Hursley Park, Winchester, Hants, SO21 2JN
____________________________________________________________

From:	Bryan Aupperle <aupperle@us.ibm.com>
To:	sca-c-cpp@lists.oasis-open.org
Date:	04/02/2009 14:49
Subject:	[sca-c-cpp] NEW ISSUE: AllowsPassByReference requires more detailed description

---

TARGET: 

C++ and C C&I specifications

DESCRIPTION: 

Currently the specification only states the requirement that the callee
must adhere to by-value semantics when indicating that a remotable interface
or function of a remotable interface allows the optimization of by-reference
parameter passing. 

It lacks a descriptions of requirements on the caller to not modify a passed
by-reference parameter during the execution of an AllowsPassByReference
function. Such concurrency situations may occur for example when 

a) the caller is inherently multi-threaded and holds-on to parameters in
concurrently executed threads 
b) the caller is called back during an invocation of an AllowsPassByReference
function(which can happen in the same thread) 
c) the AllowsPassByReference method is in addition a OneWay function(i.e.
the caller will not wait for the completion of the actual service method)

PROPOSAL: 

Discussion currently underway in the Java TC, but the key aspect is that
a client implementation must also be marked AllowsPassByReference.  We
would need to decide how to apply this approach to both C++ and C.

Bryan Aupperle, Ph.D.
STSM, WebSphere Enterprise Platform Software Solution Architect
Research Triangle Park,  NC 
+1 919-254-7508 (T/L 444-7508)
Internet Address: aupperle@us.ibm.com

---

Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU