gnat3.14p on solaris 9 crashes

gnat3.14p on solaris 9 crashes

[Pete]

Hi,

	Has anyone had a successful port of gnat onto solaris 9? I can
get basic ada programs to run but when I try to use tasks there is a
crash in ada_init. I've tried recompiling gnat on solaris 9 but that
didn't work either. Everything works fine on solaris 7, and 8. For
example the following simple program crashes on solaris 9. I don't
even have to start the task to get a seg fault. Also, if I replace
the libthread.so with libthread.so from solaris 8, it doesn't crash
but it just hangs. Maybe gnat is assuming something it shouldn't 
about the solaris threading model?

with Text_Io;

procedure Ada_Test is
	task Do_It is
		entry Start;
		entry Stop;
	end Do_It;

	task body Do_It is
	begin
		select
		   accept Start;
			   while true loop
				  Text_Io.Put_Line("Hello world");
			      select
			         accept Stop;
				     exit;
		          or
		             delay 1.0;
		          end select;	      
			   end loop;
		   or
		      terminate;
	       end select;
       end Do_It;

begin
   null;
end Ada_Test;

- pete

Re: gnat3.14p on solaris 9 crashes

[Thierry Lelegard]

>         Has anyone had a successful port of gnat onto solaris 9? I can
> get basic ada programs to run but when I try to use tasks there is a
> crash in ada_init. I've tried recompiling gnat on solaris 9 but that
> didn't work either. Everything works fine on solaris 7, and 8. For
> example the following simple program crashes on solaris 9. I don't
> even have to start the task to get a seg fault. Also, if I replace
> the libthread.so with libthread.so from solaris 8, it doesn't crash
> but it just hangs. Maybe gnat is assuming something it shouldn't
> about the solaris threading model?

Yes, this is a known problem at ACT (we had the same problem with
GNAT Pro and, as a paying customer, we reported it to ACT).

Apparently, GNAT uses some undocumented feature of libthread.so
that no longer works on Solaris 9. BTW, Sun completely redesigned
libthread.so in Solaris 9 (they call it the "T2 library").

One solution (at least with GNAT 3.15) is to use the pthread library
instead of the native thread library. Look at the gnat lib directory:

$ ls -l /opt/gnu/gnat/lib/gcc-lib/sparc-sun-solaris2.8/2.8.1/   
total 15256
lrwxrwxrwx   1 root     root          21 Oct 28 14:52 adainclude -> rts-native/adainclude
lrwxrwxrwx   1 root     root          17 Oct 28 14:52 adalib -> rts-native/adalib
....
drwxr-xr-x   4 root     root         512 May 27 22:58 rts-fsu
drwxr-xr-x   4 root     root         512 May 27 22:58 rts-native
drwxr-xr-x   4 root     root         512 May 27 22:58 rts-pthread
....
$ 

Modify the symbolic links adainclude and adalib so that they point
to rts-pthread instead of rts-native. It works with GNAT 3.15a1.

If you recompiled GNAT, you may want to fix the libthread problem
yourself. It seems that the problem is around the "self" function,
when the runtime gets the id of the current thread. Good luck.

-Thierry Lelegard