[Info-vax] ADA and VMS (was Safer programming languages)

[Arne Vajhøj]

On 11/19/2021 8:08 AM, Craig A. Berry wrote:
> 
> On 11/15/21 6:35 PM, Arne Vajhøj wrote:
>> On 11/15/2021 6:28 PM, Bill Gunshannon wrote:
>>> On 11/15/21 4:18 PM, Robert A. Brooks wrote:
>>>> On 11/15/2021 4:01 PM, Bill Gunshannon wrote:
>>>>> This talk of Ada, VMS and Systems programming has raised a new
>>>>> question in my mind.
>>>>>
>>>>> Given that Ada got it's start on VMS (one of the first validated
>>>>> Ada Compilers was on VMS) has any attempt ever been made to write
>>>>> any part of VMS using Ada?  Device Driver? Anything?
>>>>
>>>> ACME_SERVER and SECURITY_SERVER are written in ADA.
>>>>
>>>> Both are being rewritten in C.
>>>
>>> Were there ever any internal benchmarks run against them so that
>>> a comparison of performance when the C conversion is done could
>>> be looked at?
>>
>> Depending on how many checks were disabled in the Ada version, then
>> the C version may be a little or a lot faster,
>>
>> But I cannot imagine it having any significance on modern hardware.
>>
>> They did not rewrite in C to save CPU cycles but because they did
>> not have an Ada compiler for the new platform.
> 
> Right, but that doesn't mean the performance of the Ada version is good
> or that bad performance doesn't matter. In fact, ACME server performance
> is pretty lousy.  SET SERVER ACME/RESTART takes 36 seconds on an rx2660.
>   That's 36 seconds of downtime during which no one can log in to the
> system, which might not matter much in some environments, but is still a
> very long time to restart a service.

It is.

So if we say that the right time is 1 second, then those extra
35 seconds - what are they used on?

Doing Ada runtime checks??

I doubt it.

I suspect there are some bad logic that need to be redesigned.

Arne