Re: Telegen Ada guard evaluation

[bseymour@potpourri.UUCP (Burch Seymour)]

in article <27110@clyde.ATT.COM>, rds@moss.ATT.COM says:
> From Dave Stein...
> 
> Our programs have concurrent tasks, and it seems that the TeleGen compiler
> is faulty.  For one thing, it seems that guards (i.e. when statements)
> on accept statements simply do not get evaluated sometimes.
> 
I am replacing the program fragment with the entire test program which
I ran.  Gould is using the Telesoft Telegen II compiler which was just
validated under the 1.9 test suite a couple of weeks ago. It works
correctly. That is it prints "can't accept yet" 11 times then the
"we made it" and exits. Here's my program:

with text_io; use text_io;

procedure tg is

task tgtask is
  entry maybe;
end;

task body tgtask is

 x : integer := 0;
    begin
      loop
	    select
		when (x > 10) =>
		    accept maybe do
			put_line ("we made it");
		    end;
                    exit;
	    or				-- XXX
                delay 1.0;
		x := x + 1;
		put_line ("can't accept yet");
	    end select;
       end loop;
end tgtask;

begin

put_line("Start test.");
 tgtask.maybe;
put_line("Ending test.");

end tg;

> it prints "can't accept yet" 9 times, then prints "we made it" and exits.

Since the original posting had only a part of the code, I don't know
what initial value x had, but if it started at zero and the test for the
accept is x>10 then the message should be printed 11 times. Only 9 messages
would indicate a starting value of x := 2; Seems like an odd place to
start, unless there was an uninitialized x variable involved which could
explain why the original test didn't work as expected on the Telegen
compiler.

-Burch Seymour- Gould CSD  FtLauderdale, Fla 
 ...uunet!gould!bseymour  or any of a host of other possibilities
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