Hi, I added the support for AllowsByReference for the references as well as the implementation classes/methods based on the spec. Now I have some questions for the SCA spec (Ideally I should bring these questions to the SCA spec group but I don't have OASIS membership).
The following is quoted from the SCA spec: The @AllowsPassByReference annotation allows service method implementations and client references to be marked as “allows pass by reference” to indicate that they use input parameters, return values and exceptions in a manner that allows the SCA runtime to avoid the cost of copying mutable objects when a remotable service is called locally within the same JVM. 230 2.3.4 Using “allows pass by reference” to Optimize Remotable Calls 231 The SCA runtime MAY use by-reference semantics when passing input parameters, return values or 232 exceptions on calls to remotable services within the same JVM if both the service method implementation 233 and the service proxy used by the client are marked “allows pass by reference”. [JCA20009] 234 The SCA runtime MUST use by-value semantics when passing input parameters, return values and 235 exceptions on calls to remotable services within the same JVM if the service method implementation is 236 not marked “allows pass by reference” or the service proxy used by the client is not marked “allows pass 237 by reference”. [JCA20010] IIUC, now we need to mark both the reference AND service method implementation to "AllowsPassByReference" so that the runtime can optimize the in-vm calls over remotable interfaces using PBR. This seems to be too restrictive for the following use cases: 1. If the client component implementation knows that for a given reference, the operations are safe to PBR because the client side neither modifies the input parameters/return value/exceptions, nor does it care if the these data are modified by the service side. 2. If the server component implementation knows that for a given service method, the operation is safe to PBR because the server side neither modifies the input parameters/return value/exceptions, nor does it care if the these data are modified by the client side. For case 1 and 2, the PBR can be enabled independently without knowing the counterpart. Does it make sense for SCA to allow PBR if either reference OR service method implementation is marked "AllowsPassByReference"? Thanks, Raymond ________________________________________________________________ Raymond Feng rf...@apache.org Apache Tuscany PMC member and committer: tuscany.apache.org Co-author of Tuscany SCA In Action book: www.tuscanyinaction.com Personal Web Site: www.enjoyjava.com ________________________________________________________________
