1 /* 2 * Copyright (c) 2006, 2015, 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 /* 25 * @test 26 * @bug 6475157 27 * @summary Tests deadlock in simultaneous connection and connector-server close 28 * @author Eamonn McManus 29 * @modules java.management.rmi 30 */ 31 32 /* This test is somewhat dependent on implementation details. If it suddenly 33 * starts failing after a rewrite of the RMIConnectorServer code, you should 34 * consider whether it is still relevant. 35 */ 36 37 import java.io.IOException; 38 import java.lang.management.ManagementFactory; 39 import java.lang.management.ThreadInfo; 40 import java.lang.management.ThreadMXBean; 41 import java.util.concurrent.Exchanger; 42 import javax.management.MBeanServer; 43 import javax.management.remote.JMXServiceURL; 44 import javax.management.remote.rmi.RMIConnection; 45 import javax.management.remote.rmi.RMIConnectorServer; 46 import javax.management.remote.rmi.RMIJRMPServerImpl; 47 48 public class ConnectorStopDeadlockTest { 49 private static String failure; 50 private static RMIConnectorServer connectorServer; 51 52 public static void main(String[] args) throws Exception { 53 JMXServiceURL url = new JMXServiceURL("service:jmx:rmi://"); 54 MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); 55 RMIJRMPServerImplSub impl = new RMIJRMPServerImplSub(); 56 57 System.out.println("Creating connectorServer"); 58 connectorServer = new RMIConnectorServer(url, null, impl, mbs); 59 System.out.println("Starting connectorServer"); 60 connectorServer.start(); 61 System.out.println("Making client"); 62 RMIConnection cc = impl.newClient(null); 63 System.out.println("Closing client"); 64 cc.close(); 65 if (connectorServer.isActive()) { 66 System.out.println("Stopping connectorServer"); 67 connectorServer.stop(); 68 } 69 if (failure == null) 70 System.out.println("TEST PASSED, no deadlock"); 71 else 72 System.out.println("TEST FAILED"); 73 } 74 75 static void fail(Throwable e) { 76 System.out.println("FAILED WITH EXCEPTION: " + e); 77 e.printStackTrace(System.out); 78 failure = e.toString(); 79 } 80 81 static void fail(String s) { 82 System.out.println("FAILED: " + s); 83 failure = s; 84 } 85 86 // static MonitorInfo[] threadLocks(Thread t) { 87 // ThreadMXBean tm = ManagementFactory.getThreadMXBean(); 88 // ThreadInfo[] tis = tm.getThreadInfo(new long[] {t.getId()}, true, true); 89 // if (tis[0] == null) 90 // return null; 91 // else 92 // return tis[0].getLockedMonitors(); 93 // } 94 // 95 // static void showLocks(Thread t) { 96 // System.out.println("Locks for " + t.getName() + ":"); 97 // MonitorInfo[] mis = threadLocks(t); 98 // if (mis == null) 99 // System.out.println(" (no longer exists)"); 100 // else if (mis.length == 0) 101 // System.out.println(" (none)"); 102 // else { 103 // for (MonitorInfo mi : mis) 104 // System.out.println(" " + mi); 105 // } 106 // } 107 108 // Wait until thread t blocks waiting for a lock held by the calling thread, 109 // or until it exits. 110 static void waitForBlock(Thread t) { 111 Thread currentThread = Thread.currentThread(); 112 System.out.println("waiting for thread " + t.getName() + " to block " + 113 "on a lock held by thread " + currentThread.getName()); 114 ThreadMXBean tm = ManagementFactory.getThreadMXBean(); 115 while (true) { 116 ThreadInfo ti = tm.getThreadInfo(t.getId()); 117 if (ti == null) { 118 System.out.println(" thread has exited"); 119 return; 120 } 121 if (ti.getLockOwnerId() == currentThread.getId()) { 122 System.out.println(" thread now blocked"); 123 return; 124 } 125 Thread.yield(); 126 } 127 } 128 129 public static class RMIJRMPServerImplSub extends RMIJRMPServerImpl { 130 RMIJRMPServerImplSub() throws IOException { 131 super(0, null, null, null); 132 } 133 134 public RMIConnection makeClient() throws IOException { 135 return super.makeClient("connection id", null); 136 } 137 138 @Override 139 protected void clientClosed(RMIConnection conn) throws IOException { 140 System.out.println("clientClosed, will call connectorServer.stop"); 141 final Exchanger<Void> x = new Exchanger<Void>(); 142 Thread t = new Thread() { 143 public void run() { 144 try { 145 connectorServer.stop(); 146 } catch (Exception e) { 147 fail(e); 148 } 149 } 150 }; 151 t.setName("connectorServer.stop"); 152 t.start(); 153 waitForBlock(t); 154 /* If this thread is synchronized on RMIServerImpl, then 155 * the thread that does connectorServer.stop will acquire 156 * the clientList lock and then block waiting for the RMIServerImpl 157 * lock. Our call to super.clientClosed will then deadlock because 158 * it needs to acquire the clientList lock. 159 */ 160 System.out.println("calling super.clientClosed"); 161 System.out.flush(); 162 super.clientClosed(conn); 163 } 164 } 165 }