Implementation of the Legion Library

Legion is a multi-year effort to design and build scalable meta-computer software. Legion provides the software “glue ” for seamless integration of distributed, heterogeneous hardware and software components. Much of this “glue ” is provided in Legion’s run-time library. In this document we provide a detailed description of the implementation of the Legion run-time library. The library is designed and implemented as a layered, configurable software protocol stack. This design, coupled with an event-based mechanism for inter-layer communication, enables a considerable flexibility and extensibility. In this document, we first present the library interface and show how the library can be used “as is”, without internal modification. We then show how to modify or add functionality to the library. Finally, we provide qualitative descriptions of how the library could be extended to encompass programming styles and methods besides the object-oriented, macro data-flow style that is Legion’s initial target