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From: "jimmaureenrogers@worldnet.att.net" <jimmaureenrogers@worldnet.att.net>
Newsgroups: comp.lang.ada
Subject: Re: Martian Rover Spirit's mulitasking software reset.
Date: 5 Sep 2006 21:47:37 -0700
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Date: 2006-09-05T21:47:37-07:00
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ME wrote:
> The mars rover Spirit suffered a software reset as a result of a multitasking problem.
>
> "The apparent cause was that the rover's central processing unit was overworked as several tasks were running in parallel at the time."
>
>
>
> The rover uses VX works and I believe C. Testing obviously did not catch this fault. Would the use of Ada  made any difference?

Not necessarily. While there could be many reasons for this problem,
one likely one was the dynamic creation of Pthreads. A similar problem
could have been designed into an Ada program using dynamic creation of
tasks from a task type.

The problem appears to be fundamentally caused by poor design. Ada does
not prevent poor design.

On the other hand, it may have been easier to spot the problem during
code reviews using Ada, since Ada tasking is done at a much higher
level of abstraction than Pthreads using C. The higher level of
abstraction often aids in human understanding of code.

Jim Rogers