NRMI: Natural and Efficient Middleware

We present natural remote method invocation (NRMI): a middleware mechanism that provides a fully general implementation of call-by-copy-restore semantics for arbitrary linked data structures, used as parameters in remote procedure calls. Call-by-copy-restore offers a more natural programming model for distributed systems than traditional call-by-copy middleware, enabling remote calls to behave much like local calls. We discuss in depth the effects of calling semantics for middleware, describe when and why NRMI is more convenient to use than standard middleware, and present three implementations of NRMI in distinct settings, showing the generality of the approach.