C/Ada performance comparison

[Tomas Hlavaty <hlavaty@labe.felk.cvut.cz>]

Hi,

I have a question about the CPU load of Ada programs. I have a program
reimplemented from C to Ada (Linux, GNAT) and now I've found the Ada
program consumes about 7 times more CPU time than the C one. Is it
common case or does it indicate an error in my Ada implementation (I'm
quite new in Ada)? Is there any comparison/statistics on performance of
C/Ada programs?

I've tried to reduce the CPU time load of the Ada program and I found
some surprising results. I compared rts-fsu and rts-native runtime
environment and I found that rts-fsu is better (lower CPU load and only
one running process per running program compared to rts-native). Why? I
thougth rts-native should be better because it is more oriented towards
the OS (gthreads...). Why is there so many processes when executing
program compiled with rts-native? The Ada program has no tasks.

And the last question: Is there any standard/common way how to implement
synchronous I/O multiplexing like in C (select)?

Thank you,

Tomas

-- 
Tomas Hlavaty                       mailto:hlavaty@labe.felk.cvut.cz
Department of Cybernetics           http://labe.felk.cvut.cz/~hlavaty
Faculty of Electrical Engineering   phone: (+420 2) 2435 7284
Czech Technical University