A Packaging System For Heterogeneous Execution Environments

In many execution environments software components cannot interoperate easily because of differences in their interfaces and implementations. Additional software is often required to integrate such components and implement the interfacing decisions between them. For example, a procedure call across architectures may require extensive software to relocate data and coerce parameters. Even when powerful integration facilities are available, application programs need some additional software | often called`stubs' | so they can access the available communication media. Interface software can be more expensive to program that other software, since its creation requires knowledge of the machine architectures and communication mechanisms. Moreover, it must be rewritten whenever components are reused in diierent conngurations. This paper describes a way to automatically generate custom interface software for heterogeneous conngurations. Whereas previous research focused on`stub generation' alone, our approach generates stubs as well as the connguration methods needed to integrate an application. Using this approach, developers may build support tools that hide the details of how software conngurations arèpackaged' into executables. This approach is implemented within the Unix environment in a system called Polygen, which we have used for evaluation and demonstration. The results are currently being applied to prototyping problems in a project is supported by the DARPA/ISTO Common Prototyping Language initiative, in collaboration with Honeywell Systems and Research Center.