Re: Ichbiah 2022 compiler mode

[Niklas Holsti <niklas.holsti@tidorum.invalid>]

On 2024-09-12 15:36, Kevin Chadwick wrote:
> 
>> If Ada did not have tasks with priorities, most of the Ada 
>> applications I have worked on in my life would have had to avoid Ada 
>> tasking and retreat to using some other real-time kernel, with ad-hoc 
>> mapping of the kernels's threads to Ada procedures.
>>
> 
> Counter intuitively it is possible that this is holding Ada back. A lot of
> Ada code cannot run without some fairly complex runtime support due to
> tasks, protected objects, finalization etc.. Runtimes have to be developed
> for each chip instead of each cpu.


True, however an Ada RTS can implement many of the tasking features with 
moderate effort on top of non-Ada real-time kernels such as FreeRTOS, 
VxWorks, etc., as AdaCore have done for some kernels. At least for the 
Ravenscar and Jorvik profiles. AIUI, the processor-specific stuff is 
then mainly in the kernel, not in the RTS.


> If you need advanced multi core support then using an OS seems like a more
> suitable situation to be in to me.


Using a large OS like Linux would not be acceptable for many embedded 
systems. Fortunately the smaller real-time kernels are adding multi-core 
support too.

The great advantage of using the standard Ada tasking feature, special 
syntax and all, is that your embedded Ada program can then be executed 
on a PC or other non-embedded computer, for testing or other purposes, 
tasking and all. It can also be analysed by static-analysis tools such 
as AdaControl for race conditions and other tasking-sensitive issues.