1 /*
2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * The contents of this file are subject to the terms of either the Universal Permissive License
7 * v 1.0 as shown at http://oss.oracle.com/licenses/upl
8 *
9 * or the following license:
10 *
11 * Redistribution and use in source and binary forms, with or without modification, are permitted
12 * provided that the following conditions are met:
13 *
14 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions
15 * and the following disclaimer.
16 *
17 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
18 * conditions and the following disclaimer in the documentation and/or other materials provided with
19 * the distribution.
20 *
21 * 3. Neither the name of the copyright holder nor the names of its contributors may be used to
22 * endorse or promote products derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
26 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
27 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
31 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33 package org.openjdk.jmc.rjmx.test.testutil;
34
35 import java.io.IOException;
36 import java.net.DatagramPacket;
37 import java.net.DatagramSocket;
38 import java.security.AccessController;
39 import java.security.PrivilegedAction;
40
41 /**
42 * Simple, small test class to make a JVM stay awake. Takes one optional argument, which is the
43 * time, in seconds, to stay alive. If no argument is specified, the JVM will stay alive
44 * indefinitely.
45 * <p>
46 * It's meant to be used as a simple way to keep a JVM awake while testing the management console.
47 * To start a JVM with the management server, use the following argument:
48 * </p>
49 * Use the system properties -Dkill.port=<port> to specify a port other than 4713 to listen for kill
50 * commands.
51 */
52 public class JVMKeepAlive {
53 private static int m_aliveTime;
54 private static long m_startTime = System.currentTimeMillis();
55 public static final int DEFAULT_KILL_PORT = 4713;
56 public static final byte[] KILL_MESSAGE = "KILL".getBytes(); //$NON-NLS-1$
57 private static final String PROPERTY_KILL_PORT = "jmc.test.kill.port"; //$NON-NLS-1$
58
59 /**
60 * Small server that listens for datagram packets on the specified port and kills the JVM when
61 * anything is received.
62 */
63 private static class JVMKeepAliveSlayer implements Runnable {
64 @Override
65 public void run() {
66 String portStr = AccessController.doPrivileged(new PrivilegedAction<String>() {
67 @Override
68 public String run() {
69 return System.getProperty(PROPERTY_KILL_PORT, String.valueOf(DEFAULT_KILL_PORT));
70 }
71 });
72
73 int port = 0;
74 try {
75 port = Integer.parseInt(portStr);
76 } catch (NumberFormatException nfe) {
77 port = DEFAULT_KILL_PORT;
78 }
79 System.out.println(buildClassNamePrefix(JVMKeepAliveSlayer.class) + "Send kill command to port " + port //$NON-NLS-1$
80 + " to kill me."); //$NON-NLS-1$
81
82 try {
83 try (DatagramSocket s = new DatagramSocket(port)) {
84 DatagramPacket p = new DatagramPacket(new byte[25], 25);
85 s.receive(p);
86 System.exit(0);
87 }
88
89 } catch (IOException e) {
90 System.out.println(buildClassNamePrefix(JVMKeepAliveSlayer.class) + e.getMessage());
91 System.out.println(buildClassNamePrefix(JVMKeepAliveSlayer.class)
92 + "Proceeding without JRockitKeepAliveSlayer..."); //$NON-NLS-1$
93 return;
94 }
95 }
96
97 }
98
99 private static String buildClassNamePrefix(Class<?> clazz) {
100 return '[' + clazz.getName() + "] "; //$NON-NLS-1$
101 }
102
103 /**
104 * Loops for a preset time...
105 *
106 * @param args
107 * none needed
108 */
109 public static void main(String[] args) {
110 if (args.length == 1) {
111 m_aliveTime = Integer.parseInt(args[0]);
112 }
113
114 // Start the JRockitKeepAliveSlayer that listens for kill commands
115 Thread t = new Thread(new JVMKeepAliveSlayer(), buildClassNamePrefix(JVMKeepAliveSlayer.class));
116 t.start();
117
118 System.out.println(buildClassNamePrefix(JVMKeepAlive.class) + "Started..."); //$NON-NLS-1$
119
120 while (m_aliveTime == 0 || (System.currentTimeMillis() - m_startTime) / 1000 <= m_aliveTime) {
121 try {
122 Thread.sleep(2000);
123 } catch (InterruptedException e) {
124 // ignore
125 }
126 System.gc();
127 Thread.yield();
128 }
129 }
130 }