NEW ISSUE: AllowsPassByReference requires more detailed description

[Bryan Aupperle <aupperle@us.ibm.com>]

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