Re: Small example of livelock regression in garbage collector forGCJ3.3 under Win32

[Ranjit Mathew <rmathew at hotmail dot com>]

>  > >  > >>You need -fuse-divide-subroutine and -fcheck-references.  Ranjit ahd a
>  > >  > >>look at using Windows' structured exception handling to cope with
>  > >  > >>these problems, but I don't think that it's done yet.
>  > >  >
>  > >  > Andrew, if I understand this correctly, you are suggesting that
>  > >  > we use these options for the time being till such a time
>  > >  > that we can fix the SEH stuff.

[...]

>  > How does the following look (tested only on Win98 so far)? It's
>  > against 3.3 sources:
>
> That looks fine.  If it solves =?iso-8859-1?Q?=D8yvind_Harboe?='s
> problem I'll be happy.  However, he's not building his own libgcj but
> using one from Mohan, so we'll have to wait until Mohan does a rebuild
> with this patch.  Pretty please, if you would...

I must mention that even with Mohan's current build, if
I compile my "double-real-null" test program with
"-fcheck-references" it doesn't hang on Win2K as it does
(*consistently*) otherwise.

I'm attaching the test program with this message for everyone's
reference. On Win2K (and possibly on WinXP and WinNT4, but not
on Win98), this program *hangs* after printing "Strike 1!"
if compiled with Mohan's current snapshot as is, but prints
an additional "Strike 2!" and exits normally if compiled with
"-fcheck-references".

Of course beyond such trivial programs, the whole of libgcj
will have to be built with these flags for things to be
consistent.

BTW, these flags get added to "libgcj.spec" - now when I
build the GCJ cross compiler, I --disable-libgcj (to save
1 hour from the build time!) so no such file is created - does
that mean that the crossed-native GCJ/libgcj that is built
using this cross compiler will *not* be compiled using
these flags?

If yes, I need to look at some other way to propagate
these flags to the GCJ cross-compiler without having to
build the whole of libgcj.

Ranjit.

--
Ranjit Mathew          Email: rmathew AT hotmail DOT com

Bangalore, INDIA.      Web: http://ranjitmathew.tripod.com/
public class DNull 
{
  public static void main( String[] args) 
  {
    Object p = null;

    try 
    {
      System.out.println( p.toString( ));
    } 
    catch( NullPointerException e) 
    {
      System.err.println( "Strike 1!");
    }

    try 
    {
      System.out.println( p.toString( ));
    } 
    catch( NullPointerException e) 
    {
      System.err.println( "Strike 2!");
    }
  }
}