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 than other software, since its creation requires knowledge of the machine architectures and communication mechanisms. Moreover, it must be rewritten whenever components are reused in different configurations. This paper describes a way to automatically generate custom interface software for heterogeneous configurations. Whereas previous research focused on "stub generation" alone, our approach generates stubs as well as the configuration methods needed to integrate an application. Using this approach, developers may build support tools that hide the details of how software configurations are "packaged" into executables. This approach is implemented within the Unix environment in a system called Polygen, which we have used for evaluation and demonstration.