A Tool command language binding for the High-Level Architecture - ATHLA

Abstract

The High-Level Architecture (HLA) is a framework for the creation of distributed simulations. It has its roots in the experiences from Aggregate Level Simulation Protocol (ALSP) and Distributed Interactive Simulation (DIS) work of the US Department of Defense (DoD). The objective was to smooth reusability and interoperability of simulation components. HLA has its latest new-generation IEEE standard representation as IEEE 1516-2010, also called HLA Evolved. This standard defines the behavior of the so-called runtime infrastructure (RTI), which is the associated software layer. A Federation Object Model (FOM) describes the attributes, objects and interactions that are exchanged in a federation. Commercial RTI application programming interfaces (APIs) mainly cover Java and C++ language bindings. The presentation will introduce a Tool command language (Tcl) API built on top of a current commercial Java API using the JBlend Tcl package that provides access to Java classes from Tcl. The motivation arose from combining Tcl’s benefits of a “glueing” language with the advantages of HLA. A parallel approach covers new aspects of the next version of HLA called “HLA 4”, which his currently under development. It is expected to deliver a three layer point-to-point TCP protocol beside its traditional Local RTI Components (LRCs) provisioning in terms of vendor specific libraries. The services layer will cover the HLA services in an efficient binary encoded form, where Protobuf (Google 2008) was selected as protocol encoder. ATHLA’s access to HLA service calls mapped into Protobuf messages will be realized via the supported C++ API. The HLA service messages’ definitions containing *.proto file, as part of “HLA 4”, will be fed to the publicly available protocol buffer compiler. This will generate the classes in the *.pb.h and *.pb.cc files to read and write the HLA services messages. These files in combination with developed implementation code will be used with the Compiled Runtime In Tcl (Critcl) (Kupries 2016) package to result in a Tcl binding to HLA 4 extension for ATHLA.

REFERENCES Google 2008. “Protocol Buffers - Google's data interchange format”. https://github.com/protocolbuffers/protobuf. Accessed Mar. 13, 2023. Kupries, A. 2016. “C Runtime In Tcl”. https://www.tcl.tk/community/tcl2016/assets/talk35/critclpaper.pdf. Accessed Mar. 13, 2023.