4 ms·

In light of decades of demonstrated reliability of Ada use in aerospace applications, a bunch of comments about Ada from the late 1980s are meaningless.

zozbot234 5y ago
The quoted comment is saying that the Ada support runtime is so high level that it sometimes ends up being unsuitable for real-time programming. This is exactly the kind of concern that would be hard to improve even in recent versions of Ada, whereas it is naturally addressed by Rust.
- pjmlp 5y ago
  Except it ignores the little detail of stuff like Ravescar profile. https://en.wikipedia.org/wiki/Ravenscar_profile https://en.wikipedia.org/wiki/Ravenscar_profile
- touisteur 5y ago
  That's one of those times when looking around at what exists and not only old papers might help. Been doing soft and hard real-time on baremetal (no OS) with Ada tech for a long time. There's a whole of language constructions to help reducing the language set for hard embedded stuff (no dynamic allocation, no specific constructs, no secondary stack,...) and there are the Ravenscar and Jorvik profiles. Very strange to hear/read about non implementability of hard real-time with Ada when one the guy I hired years ago was one of the OS-for-aircraft-embedded-computer, doing that since the 90s...
- ajxs 5y ago
  How do you figure Rust handles this better than Ada? Ada's runtime has always been configurable. You can customise the runtime library fairly easily to strip out things that don't suit your target platform. Most compilers even ship with a 'Zero Footprint (zfp)' runtime which is designed for minimal overhead. You could make the exact same argument about C if you wanted. C's standard library, as implemented for most operating systems, is poorly suited for real-time systems too. That's why it's modified to be fit for purpose when targeting them. Whether people know it or not, they've been living in the Ada world for a long time. A good deal of the world's critical real-time systems have been running on Ada for decades. Flight, and fire control systems in aircraft, Many major ATC systems, etc. The list goes on, and on.

zozbot234 5y ago

The quoted comment is saying that the Ada support runtime is so high level that it sometimes ends up being unsuitable for real-time programming. This is exactly the kind of concern that would be hard to improve even in recent versions of Ada, whereas it is naturally addressed by Rust.

pjmlp 5y ago
Except it ignores the little detail of stuff like Ravescar profile. https://en.wikipedia.org/wiki/Ravenscar_profile https://en.wikipedia.org/wiki/Ravenscar_profile
touisteur 5y ago
That's one of those times when looking around at what exists and not only old papers might help. Been doing soft and hard real-time on baremetal (no OS) with Ada tech for a long time. There's a whole of language constructions to help reducing the language set for hard embedded stuff (no dynamic allocation, no specific constructs, no secondary stack,...) and there are the Ravenscar and Jorvik profiles. Very strange to hear/read about non implementability of hard real-time with Ada when one the guy I hired years ago was one of the OS-for-aircraft-embedded-computer, doing that since the 90s...
ajxs 5y ago
How do you figure Rust handles this better than Ada? Ada's runtime has always been configurable. You can customise the runtime library fairly easily to strip out things that don't suit your target platform. Most compilers even ship with a 'Zero Footprint (zfp)' runtime which is designed for minimal overhead. You could make the exact same argument about C if you wanted. C's standard library, as implemented for most operating systems, is poorly suited for real-time systems too. That's why it's modified to be fit for purpose when targeting them. Whether people know it or not, they've been living in the Ada world for a long time. A good deal of the world's critical real-time systems have been running on Ada for decades. Flight, and fire control systems in aircraft, Many major ATC systems, etc. The list goes on, and on.