Asynchronous abort not working in Debian GNAT?

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

Under Debian Sarge on Intel, gnat 3.15p, I implemented a time-out for an 
application using the canonical construct:

     select
        delay Time_Out;
        Error (...);
     then abort
        Processing (...);
     end select;

After upgrading to Debian Lenny, FSF GNAT 4.3.2, it appears that this no 
longer works; instead, Processing completes without being aborted, 
unless Processing does something that probably invokes scheduling, for 
example "delay 0.0" or Text_IO output to the console.

Running "strace" on the program shows that a SIGABRT is signalled at 
TIme_Out, but does not abort Processing until Processing does something 
like delay or console output. The GNAT polling option (-gnatP) does not 
seem to help.

I did not find any Debian bug report on this issue. Has anyone else seen 
this? Do you know of work-arounds? Other than sprinkling the code with 
frequent delay statements.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
       .      @       .