Re: Computer architects leaving Intel...

Stephen Fuld wrote:

On 9/3/2024 8:46 AM, Terje Mathisen wrote:
 > Stephen Fuld wrote:
 >> On 9/2/2024 1:23 AM, Terje Mathisen wrote:
 >>> Stephen Fuld wrote:
 >>>> On 8/31/2024 2:14 PM, MitchAlsup1 wrote:
 >>>>> On Sat, 31 Aug 2024 21:01:54 +0000, Bernd Linsel wrote:
 >>>>>> You compare apples and peaches. Technical specifications for your
 >>>>>> pressure vessel result from the physical abilities of the chosen
 >>>>>> material, by keeping requirements as vessel border width, geometry
 >>>>>> etc.,
 >>>>>> while compiler writers are free in their search for optimization
 >>>>>> tricks
 >>>>>> that let them shine at SPEC benchmarks.
 >>>>>
 >>>>> A pressure vessel may actually be able to contain 2× the
 >>>>> pressure it
 >>>>> will be able to contain 20 after 20 years of service due to stress
 >>>>> and strain acting on the base materials.
 >>>>>
 >>>>> Then there are 3 kinds of metals {grey, white, yellow} with different
 >>>>> responses to stress and induced strain. There is no analogy in code--
 >>>>> If there were perhaps we would have better code today...
 >>>>
 >>>> Perhaps an analogy is code written in assembler, versus coed written
 >>>> in C versus code written in something like Ada or Rust.  Backing
 >>>> away now . . . :-)
 >>>
 >>> IMNSHO, code written in asm is generally more safe than code written
 >>> in C, because the author knows exactly what each line of code is
 >>> going to do.
 >>>
 >>> The problem is of course that it is harder to get 10x lines of
 >>> correct asm than to get 1x lines of correct C.
 >>>
 >>> BTW, I am also solidly in the grey hair group here, writing C code
 >>> that is very low-level, using explicit local variables for any loop
 >>> invariant, copying other stuff into temp vars in order to make it
 >>> really obvious that they cannot alias any globals or input/output
 >>> parameters.
 >>>
 >>> Anyway, that is all mostly moot since I'm using Rust for this kind of
 >>> programming now. :-)
 >>
 >> Can you talk about the advantages and disadvantages of Rust versus C?
 >
 > Q&D programming is still far faster for me in C, but using Rust I don't
 > have to worry about how well the compiler will be able to optimize my
 > code, it is pretty much always close to speed of light since the entire
 > aliasing issue goes away.
 >
 > Rust also gets rid of the horrible external library/configure/cmake mess
 > that kept me from successfully compiling the reference LAStools lidar
 > code for nearly 10 years.
 >
 > Using the Rust port I just tell cargo to add it to my project and that's
 > it.
 Thank you.  I find it interesting that the main advantage of Rust as touted by its evangelists, memory safety, didn't make your list.

Possibly because, due to the way I've been writing C(++) code for the last 40 years, I have almost never been hit by those problems myself?
OTOH, in retrospect I know I have written a lot of code that would not have survived an experienced attacker, i.e. strcpy()/memcpy()/etc without explicit checks that the target buffer is large enough.
This is of course fine in the classic "everyone is a friend, all code is open source, and nobody wants to actively attack us" environment, but not so much for anything exposed to the Internet.
During my NTP Hackers time we never had memory overruns afair, but we did get a lot of abuse when DoS attacks were using our by default open debug/monitoring interface to amplify attacks on other systems. This was similar to the classic DNS abuse for the same purpose.
Yes, I do like the Rust memory safety, but it does nothing to prevent attacks of that type: We had to switch from UDP to TCP for all requests that could produce outputs larger than the input size.
Terje
--
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"