Java tutorial
/* * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.lang; import jdk.internal.misc.Signal; /** * Package-private utility class for setting up and tearing down * platform-specific support for termination-triggered shutdowns. * * @author Mark Reinhold * @since 1.3 */ class Terminator { private static Signal.Handler handler = null; /* Invocations of setup and teardown are already synchronized * on the shutdown lock, so no further synchronization is needed here */ static void setup() { if (handler != null) return; Signal.Handler sh = new Signal.Handler() { public void handle(Signal sig) { Shutdown.exit(sig.getNumber() + 0200); } }; handler = sh; // When -Xrs is specified the user is responsible for // ensuring that shutdown hooks are run by calling // System.exit() try { Signal.handle(new Signal("INT"), sh); } catch (IllegalArgumentException e) { } try { Signal.handle(new Signal("TERM"), sh); } catch (IllegalArgumentException e) { } } static void teardown() { /* The current sun.misc.Signal class does not support * the cancellation of handlers */ } }