1 /*
   2  * Copyright (c) 2016, 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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 import java.io.*;
  25 import java.net.InetSocketAddress;
  26 import java.net.ProtocolFamily;
  27 import java.nio.channels.Channel;
  28 import java.nio.channels.DatagramChannel;
  29 import java.nio.channels.Pipe;
  30 import java.nio.channels.ServerSocketChannel;
  31 import java.nio.channels.SocketChannel;
  32 import java.nio.channels.spi.AbstractSelector;
  33 import java.nio.channels.spi.SelectorProvider;
  34 import static java.net.StandardSocketOptions.SO_REUSEADDR;
  35 import static java.net.StandardSocketOptions.SO_REUSEPORT;
  36 
  37 /**
  38  * A SelectorProvider, that can be loaded by the child rmid process, whose
  39  * inheritedChannel method will create a new server socket channel and report
  40  * it back to the parent process, over stdout.
  41  */
  42 public class RMIDSelectorProvider extends SelectorProvider {
  43 
  44     private final SelectorProvider provider;
  45     private ServerSocketChannel channel;
  46 
  47     public RMIDSelectorProvider() {
  48         provider = sun.nio.ch.DefaultSelectorProvider.create();
  49     }
  50 
  51     public DatagramChannel openDatagramChannel()
  52         throws IOException
  53     {
  54         return provider.openDatagramChannel();
  55     }
  56 
  57     public DatagramChannel openDatagramChannel(ProtocolFamily family)
  58         throws IOException
  59     {
  60         return provider.openDatagramChannel(family);
  61     }
  62 
  63     public Pipe openPipe()
  64         throws IOException
  65     {
  66         return provider.openPipe();
  67     }
  68 
  69     public AbstractSelector openSelector()
  70         throws IOException
  71     {
  72         return provider.openSelector();
  73     }
  74 
  75     public ServerSocketChannel openServerSocketChannel()
  76         throws IOException
  77     {
  78         return provider.openServerSocketChannel();
  79     }
  80 
  81     public SocketChannel openSocketChannel()
  82         throws IOException
  83     {
  84         return provider.openSocketChannel();
  85     }
  86 
  87     public synchronized Channel inheritedChannel() throws IOException {
  88         System.out.println("RMIDSelectorProvider.inheritedChannel");
  89         if (channel == null) {
  90             // Create and bind a new server socket channel
  91             channel = ServerSocketChannel.open();
  92 
  93             // Enable SO_REUSEADDR before binding
  94             channel.setOption(SO_REUSEADDR, true);
  95 
  96             // Enable SO_REUSEPORT, if supported, before binding
  97             if (channel.supportedOptions().contains(SO_REUSEPORT)) {
  98                 channel.setOption(SO_REUSEPORT, true);
  99             }
 100 
 101             channel.bind(new InetSocketAddress(0));
 102 
 103             System.out.println(RMID.EPHEMERAL_MSG + channel.socket().getLocalPort());
 104         }
 105         return channel;
 106     }
 107 }