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

[Bill Gunshannon]

On 11/15/21 9:23 PM, Arne Vajhøj wrote:
> On 11/15/2021 8:44 PM, Bill Gunshannon wrote:
>> On 11/15/21 7:35 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.
>>
>> I realize all that.  I would just like to see some comparisons.
>> I don't know that any were actually done.  It all goes back to
>> a comment I got from someone from the Ada Users Group about 30
>> years ago.  I mentioned an interest in a version of Unix rewritten
>> in Ada and was quickly informed that while it could be done it
>> would result in a useless operating system because the Ada version
>> would be very inefficient.  Needless to say, I never tried it.
>> Might be fun to dig up some benchmarks and try it, but I always
>> prefer real world examples to contrived benchmarks.
> 
> But there are two very different questions here.
> 
> Would Ada vs C for OS mean something 30 years ago (VAX 6000 and 3000)?
> 
> Would Ada vs C for OS mean something today (16/24/32 core x86-64)?
> 

Thus the reason we have so much bloatware today.  If the program
runs badly, throw more cores at it. I am not interested in whether
or not something ran faster or slower on todays machines vs. yesterdays.
I am interested in whether or not ADD A TO B GIVING C is faster, slower
or the same between Ada and C.( and other languages as well!) Throwing
more cores at the above will not result in faster performance.

When I first started with programming we cared about programming and
efficiency.  We profiled our programs in order to find the bad parts
and we fixed them.  It is sad that efficiency is no longer considered
important to software development today.  And they call it engineering
while we just called it programming.

bill