From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,3ccb707f4c91a5f2 X-Google-Attributes: gid103376,public From: John Cosby Subject: Ada and the DoD HLA (was: Once again, Ada absent from DoD SBIR solicitation) Date: 1996/10/11 Message-ID: <325EBED8.41C6@cpmx.saic.com>#1/1 X-Deja-AN: 188902509 references: <01bbb57f$7fb59020$72663389@billn.logicon.com> <325BC3B3.41C6@hso.link.com> cc: s_allen@hso.link.com, John.D.Cosby@cpmx.saic.com content-type: text/plain; charset=us-ascii organization: SAIC Orlando mime-version: 1.0 newsgroups: comp.lang.ada x-mailer: Mozilla 3.0 (X11; I; OSF1 V3.2 alpha) Date: 1996-10-11T00:00:00+00:00 List-Id: Stanley R. Allen wrote: > My company's job is building big simulators, and the > new DoD *mandate* (sound familiar?) for simulations is > called HLA (High Level Architecture), which is being > developed by the Defense Modeling and Simulation > Office (DMSO) See http://www.dmso.mil/projects/hla/ > for some interesting overview and mandate stuff. This is a mandate with teeth - HLA compliance is specified in the contracts being proposed and awarded now, and has been back-filled into existing developments. Unlike the Ada mandate, which isn't often specified in the contract, or lets folks weasle out. > It's a good idea. It's time has come. But the first > cut of the HLA API is given in .... C++ ! No mention > of Ada anywhere. No justification is given for > avoiding the Ada madate. And HLA is a *big* *deal*. > All the major DoD simulator contractors are hankering > after this work. First, it's not the HLA API - it's the first implementation of the HLA Runtime Infrastructure that's being written in C++. The original design was to use CORBA IDL to specify the interfaces, allowing any language for which an emitter exists to be used. The prototype versions of the RTI, up to and including RTI 1.0, are being developed by the gov't (MITRE and MIT Lincoln Labs) in C++. The gov't is supposed to solicit commercial development of one or more RTIs Real Soon Now - the prototype should be all grown up around February. You want mention of Ada? DMSO funded several efforts to use the prototype RTI and get feedback from different groups of simulation users. Originally (and this is buried in the AMG minutes on the web site), there was to have been an Ada front-end, but the RTI developers had so much trouble with the initial prototype releases they couldn't support a parallel effort. We (I worked one of the "proto-federation" efforts) had to interface our Ada simulation system to the C++ interfaces generated from the IDL interface specification. Why didn't we just use the Ada95 CORBA IDL emitter for our ORB? It didn't exist yet; it came along about the time the protofederation effort ended. Believe me, there's been talk about Ada - not too productive, but the issue's never been killed. > So, two DoD mandates mitigate against one another. > (Homework: ask yourself seriously which one will win.) > Note that HLA-compliance for simulators must be > considered new development; there is no such thing > as a COTS HLA-based system. It's too new. So, the > COTS excuse is no reason. Um... actually, the "commercial RTI" may be considered COTS eventually, or GOTS. DMSO _really_ doesn't want every simulation effort writing their own RTI - that would make interoperability a problem - they want everyone using a "standard" RTI. (Unlike the old DIS and ALSP standards, HLA specifies object models and leaves it to the RTI to sweat the bit-formats going out over the network - there's no way to guarantee interoperability of two "HLA compliant" simulations using different RTIs). If the RTI's in C++, this could indeed be a problem - I learned a lot of hard lessons about making C++ callable from Ada over the last six months. And yes, I'm very nervous about using an RTI written in C++. Can't you tell? > If you believe in the promise of Ada (as I do), you > could do yourself a favor by listening to Gregory > Aharonian. And then doing something about it. I am. Sometime in November, I get to start giving feedback to the Ada interface specification that should be published with the RTI 1.0 release; I also get to go to work in Nov./Dec. porting the RTI to the IBM RS/6000 platform, hopefully with an Ada95 front-end. Anyway, that's the plan. Check with me in December and I'll let you know how it's going. John -- John Cosby | Opinions expressed are those of the individual SAIC Orlando | and in no way represent any official position John.D.Cosby@cpmx.saic.com | or opinion of SAIC unless specifically noted. (407) 282-6700 x216 | Live long and perspire....