Turns out Sun has secret support for handling signals, so we'll use that

instead of our native library. I've left the native library support in in case
the Sun stuff is not available, but that's so extremely unlikely in a server
environment (IBM recreates Sun's signal handling in their VM because it's so
dang useful) that I should probably just nix it altogether and simplify things.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4710 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/server/AbstractSignalHandler.java

@@ -0,0 +1,63 @@
+//
+// $Id$
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2007 Three Rings Design, Inc., All Rights Reserved
+// http://www.threerings.net/code/narya/
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.threerings.presents.server;
+
+import static com.threerings.presents.Log.log;
+
+/**
+ * A base class that is used to wire up signal handling in one of a couple of possible ways.
+ */
+public abstract class AbstractSignalHandler
+{
+    public boolean init (PresentsServer server)
+    {
+        _server = server;
+        return registerHandlers();
+    }
+
+    /**
+     * Signal handler implementations should wire themselves up in the call to this method.
+     *
+     * @return true if the handlers were successfully wired up, false if they were not able to be
+     * wired up.
+     */
+    protected abstract boolean registerHandlers ();
+
+    /**
+     * Implementations should call this method when a SIGINT is received.
+     */
+    protected void intReceived ()
+    {
+        log.info("Shutdown initiated by INT signal.");
+        _server.queueShutdown();
+    }
+
+    /**
+     * Implementations should call this method when a SIGHUP is received.
+     */
+    protected void hupReceived ()
+    {
+        log.info(_server.generateReport());
+    }
+
+    protected PresentsServer _server;
+}