Re: A Modest Exercise in Ada Program Portability

[mackey@scs.fiu.edu]

In article <2373@sparko.gwu.edu> mfeldman@seas.gwu.edu (Michael Feldman) writes:
>Here is an exercise in Ada program portability. It is an implementation
>of the famous Dining Philosophers problem, first posed by E. Dijkstra in
>...
>This exercise has been successfully compiled and executed, without needing to
>change any source code, under the following compilers:
>IBM-PC      Meridian AdaZ
>IBM-PC      AETech IntegrAda (same compiler as Janus Ada)
>HP9000/300  Verdix VADS (HP/UX)
>HP9000/800  Irvine Compiler Corporation ICC Ada (HP/UX)
>Sun-3       Verdix VADS (SunOS 4.0)
>Sun-3       TeleSoft Telegen2 (SunOS 4.0)
>Sun-3       Meridian AdaVantage (SunOS 4.0)
>...
>Please try this on your favorite compiler and let me know if your
>experience differs from mine.

........

The code also runs (almost) unchanged on VAX/VMS with the DEC Ada
compiler.  The only needed change was a pragma at the front of 
``diners.ada'', changing:
	WITH Room;
	PROCEDURE Diners IS
	...
into:
	WITH Room;
	with Control_C_Interception; -- Ensure ^Y or ^C kills process.
	pragma elaborate( Control_C_Interception );
	PROCEDURE Diners IS
	...
Actually, the program does work without this modification, but is slow
to stop when Ctrl/C is hit.  With the pragma, a Ctrl/C gets attention
from the runtime routines which accept an exit/continue/... command.
Without it, a task which is sleeping in a delay statement only stops
when it wakes up rather than immediately.

........

The code was written for a vt100 terminal not a shelltool on the
suns, but works fine in a shelltool with the change of:
	put( ESC & "[2J" );
to:
	put( FF );
in the vtbody.ada package body.  It also runs on a sun4 under
Telesoft Telegen2.  No change was needed to run in a te100tool window
either locally on a Sun3 or on a Sun3 te100tool rlogin'd to a Sun4.

.