* Re: Ada PIWG
1989-12-01 13:59 Ada PIWG Ted Holden
@ 1989-12-01 21:18 ` Jeffrey Stewart
1989-12-01 22:08 ` Terri Richard
1989-12-01 22:56 ` Roger Racine
2 siblings, 0 replies; 4+ messages in thread
From: Jeffrey Stewart @ 1989-12-01 21:18 UTC (permalink / raw)
In article <14062@grebyn.com> ted@grebyn.com (Ted Holden) writes:
>The literature and every conversation I have ever had with real-world
>people who have been forced to actually attempt to USE Ada have totally
>convinced me of the failure of this project. By the same token, C++
>could very nearly, if not entirely, fill the bill.
Well Ted, I guess you never talked to me or the group I worked with at
Hercules Defense Electronics.
We have just finished a project to implement all of the control software
plus some signal-processing software, in Ada, for a Millimeter-Wave radar
seeker for the Maverick missile.
Its about 7500 lines of code, based on an object-oriented design, does
signal-processing, provides dual-loop control for the antenna, provides
mission control for the entire missile, plus some other things. And it
does it at 600Hz, on a 10MHz 80286. There is NO ASSEMBLER. The goal
was a complete Ada artifact, and the goal was achieved.
We wanted a complete Ada artifact because part of the goal was for the
implementation to be as portable as possible. We achieved this, in part,
by rewriting some of the system requirements to be event, rather than timing,
driven. There was zero loss of functionality and performance due to these
changed requirements.
We had NO problems with the language. We did have one problem with the
compiler generating incorrect code for a representation clause, but this was
a compiler implementation problem which was easily fixed by the vendor.
Projects that DO have a problem with Ada tend to fall into the following
categories :
The classic "10 pounds of stuff into a 5 pound bag" problem. You won't
solve this with C either. Many times, the requirements stack the deck
against you. Period.
Less than production-quality compilers. I'll admit this was a problem,
and is less so every day.
Whiners who will use every excuse to blame the language rather than the
design. The two ARE different, design and implementation, don'cha know?
Many of these projects fail due to poor design, regardless of
implementation language.
I refuse to assign percentages to these categories. Let that be an exercise
for the reader.
By the way Ted, part of the rationale for Ada was that the techniques and
languages in current use (mid 70's) would be inadequate for the million-plus
SLOC systems anticipated for the 90's. What are the successful C-language
projects of this size?
I like Ada not because it is Ada, but because, in my estimation, it allows
the best use to-date of all the software engineering principles I know and
have seen used effectively. Most C code still looks like line-noise to me.
To sum up, Ada DOES work, for its intended purposes. Maybe you should
consider becoming an equal opportunity basher, i.e., cite some C/C++
failures as well. (And don't tell me there aren't any. Your use of
absolute terms is part of what detracts from your credibility.)
Jeff
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Ada PIWG
1989-12-01 13:59 Ada PIWG Ted Holden
1989-12-01 21:18 ` Jeffrey Stewart
1989-12-01 22:08 ` Terri Richard
@ 1989-12-01 22:56 ` Roger Racine
2 siblings, 0 replies; 4+ messages in thread
From: Roger Racine @ 1989-12-01 22:56 UTC (permalink / raw)
The PIWG (Performance Issues Working Group) has a very useful set of
tests for benchmarking Ada compilers. Ted Holden, you are wasting an
awful lot of time and money sending these misstatements around the
country. You do not have to like Ada. You may have to use it if you
do work on new DoD projects. But what purpose does it serve to answer
a request for information on a serious subject with a lot of rhetoric
without any facts to back up your statements?
Back to the PIWG. To attempt to compare compilers, operating systems,
databases, and other software systems, people have been creating
benchmarks for years (Whetstones, Dhrystones, etc.), no matter what
Ted Holden says. Byte Magazine has a set of tests for comparing
computer systems. PIWG created a set for testing Ada compilers and
runtime environments.
It is not easy to create standard tests for interrupts u knows
the hardware. So the last time I used the PIWG, it did not support
testing that. However, they have been working on it, and it could be
available.
The correct person to contact is Dan Roy (301) 464-6800. He chairs the
working group.
Roger Racine
^ permalink raw reply [flat|nested] 4+ messages in thread