InvokeRegistry

GetRemotableDataContext returns a pointer to the data context object that stores all the temporary objects and values needed for implementing a call to an invokable interface. When a client application calls an invokable interface on a Web Service application, the Web Service application automatically creates a data context for the call. Any objects or variables that are needed for marshaling the interface call are automatically added to the data context for the duration of the call. In addition, any remotable objects (TRemotable descendants) that are created while there is a remotable data context available are automatically added to the data context. When the interface call is complete, the data context is freed, and it automatically frees the stored objects and variables. 

SetRemotableDataContext 

TRemotable 

TDataContext