Re: non-preemptive tasking on GNAT 2020 Windows 10 multicore AMD

[Dan Winslow <dandwinslow@gmail.com>]

On Sunday, June 13, 2021 at 8:16:31 AM UTC-5, Jeffrey R. Carter wrote:
> On 6/13/21 2:06 PM, Dan Winslow wrote: 
> > 
> > Well. You are confirming that I shouldn't expect the behavior I am looking for? How does linux do in this regard, I could use it if needed.
> with Xubuntu 21.04 and GNAT 11 I get 
> 
> ~/Code$ ./winslow 
> 8 CPUs 
> one 
> Task one done, x= 1000001 
> two
> Task two done, y= 1000001
> main done, x 1000001 y 1000001 
> 
> I get this with or without the scheduling pragma in gnat.adc. 
> 
> -- 
> Jeff Carter 
> "Don't knock masturbation. It's sex with someone I love." 
> Annie Hall 
> 45
Yep, just found that myself. So, I guess since the tasks get mapped onto underlying os threads, windows has its own ideas and does things like automatic priority promotion and other non-compliant stuff. Too bad, but I guess kind of makes sense because windows does everything possible, most likely, to prevent any kind of thread monopolization. Would be nice if the gnat windows version at least threw a warning that 'hey, it's legal, but it aint gonna work on windows'.

So, works perfectly on linux. Probably would on windows too if I knew how to swap out for a pthreads implementation on windows.

Thanks!