1 /*
   2  * Copyright (c) 1999, 2001, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.lang;
  27 
  28 import sun.misc.Signal;
  29 import sun.misc.SignalHandler;
  30 
  31 
  32 /**
  33  * Package-private utility class for setting up and tearing down
  34  * platform-specific support for termination-triggered shutdowns.
  35  *
  36  * @author   Mark Reinhold
  37  * @since    1.3
  38  */
  39 
  40 class Terminator {
  41 
  42     private static SignalHandler handler = null;
  43 
  44     /* Invocations of setup and teardown are already synchronized
  45      * on the shutdown lock, so no further synchronization is needed here
  46      */
  47 
  48     static void setup() {
  49         if (handler != null) return;
  50         SignalHandler sh = new SignalHandler() {
  51             public void handle(Signal sig) {
  52                 Shutdown.exit(sig.getNumber() + 0200);
  53             }
  54         };
  55         handler = sh;
  56         try {
  57             Signal.handle(new Signal("HUP"), sh);
  58             Signal.handle(new Signal("INT"), sh);
  59             Signal.handle(new Signal("TERM"), sh);
  60         } catch (IllegalArgumentException e) {
  61             // When -Xrs is specified the user is responsible for
  62             // ensuring that shutdown hooks are run by calling
  63             // System.exit()
  64         }
  65     }
  66 
  67     static void teardown() {
  68         /* The current sun.misc.Signal class does not support
  69          * the cancellation of handlers
  70          */
  71     }
  72 
  73 }