libgcj/289

[Tom Tromey <tromey at cygnus dot com>]

The following reply was made to PR libgcj/289; it has been noted by GNATS.

From: Tom Tromey <tromey@cygnus.com>
To: osk@hem.passagen.se
Cc: Java Gnats Server <java-gnats@sourceware.cygnus.com>
Subject: libgcj/289
Date: 10 Sep 2000 23:18:22 -0600

 I've investigated this some more.
 
 I experimented with the JDK.  With the JDK interpreter, if the main
 thread throws an uncaught exception and then exits (because that was
 the last thread) then the runtime with exit with status 1.
 
 But consider the appended program.  This program attempts to determine
 what happens if the main thread throws an exception but is not the
 last thread to stop.  In this situation, what should happen?  I don't
 know, because the JDK hangs.  (Maybe there is a bug in my test, feel
 free to enlighten me.)
 
 I don't think we should do anything special here.  I agree it is less
 than perfect, but it isn't clear what the right thing is, and
 compatibility with the JDK seems hard.
 
 If the situation changes wrt the JDK, feel free to reopen the PR.  We
 can always address it later.
 
 Tom
 
 public class q implements Runnable
 {
   public static Thread t_bad, t_good;
 
 
   public boolean bad_flag;
 
   public void run () throws InterruptedException
   {
     if (bad_flag)
       {
 	throw new NullPointerException ("zardoz!");
       }
     else
       {
 	t_bad.join ();
       }
   }
 
   public q (boolean x)
   {
     bad_flag = x;
   }
 
   public static void main (String[] args) throws InterruptedException
   {
     q t1 = new q (true);
     q t2 = new q (false);
 
     t_bad = Thread.currentThread ();
     t_good = new Thread (t2);
     t_good.start ();
     t1.run ();
   }
 }