1 /*
   2  * Copyright (c) 1998, 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 /* @test
  25  * @bug 4164696
  26  * @summary The local garbage collector needs to inspect a client VM's heap
  27  * often enough (even if the VM is idle) to detect unreachable live remote
  28  * references, so that their server VMs can be informed that the client VM
  29  * is no longer holding a reference; this facilitates the server VM invoking
  30  * the remote object's unreferenced() method (if present), garbage collecting
  31  * the remote object, and allowing the server VM to exit.  This test focuses
  32  * on the unreferenced() method being invoked: it tests that the callback
  33  * method will be invoked within a reasonable time after the remote object is
  34  * no longer remotely reachable.
  35  * @author Peter Jones
  36  *
  37  * @library ../../../testlibrary
  38  * @modules java.rmi/sun.rmi.registry
  39  *          java.rmi/sun.rmi.server
  40  *          java.rmi/sun.rmi.transport
  41  *          java.rmi/sun.rmi.transport.tcp
  42  * @build TestLibrary FiniteGCLatency_Stub
  43  * @run main/othervm/timeout=120 FiniteGCLatency
  44  */
  45 
  46 import java.rmi.*;
  47 import java.rmi.registry.*;
  48 import java.rmi.server.*;
  49 
  50 public class FiniteGCLatency implements Remote, Unreferenced {
  51 
  52     private final static String BINDING = "FiniteGCLatency";
  53     private final static long GC_INTERVAL = 6000;
  54     private final static long TIMEOUT = 50000;
  55 
  56     private Object lock = new Object();
  57     private boolean unreferencedInvoked = false;
  58 
  59     public void unreferenced() {
  60         System.err.println("unreferenced() method invoked");
  61         synchronized (lock) {
  62             unreferencedInvoked = true;
  63             lock.notify();
  64         }
  65     }
  66 
  67     public static void main(String[] args) {
  68 
  69         System.err.println("\nRegression test for bug 4164696\n");
  70 
  71         /*
  72          * Set the interval that RMI will request for GC latency (before RMI
  73          * gets initialized and this property is read) to an unrealistically
  74          * small value, so that this test shouldn't have to wait too long.
  75          */
  76         System.setProperty("sun.rmi.dgc.client.gcInterval",
  77             String.valueOf(GC_INTERVAL));
  78 
  79         FiniteGCLatency obj = new FiniteGCLatency();
  80 
  81         try {
  82             UnicastRemoteObject.exportObject(obj);
  83             System.err.println("exported remote object");
  84             Registry registry1 = TestLibrary.createRegistryOnEphemeralPort();
  85             int port = TestLibrary.getRegistryPort(registry1);
  86             System.err.println("created registry");
  87 
  88             Registry registry = LocateRegistry.getRegistry("", port);
  89             registry.bind(BINDING, obj);
  90             System.err.println("bound remote object in registry");
  91 
  92             synchronized (obj.lock) {
  93                 registry.unbind(BINDING);
  94                 System.err.println("unbound remote object from registry; " +
  95                     "waiting for unreferenced() callback...");
  96                 obj.lock.wait(TIMEOUT);
  97 
  98                 if (obj.unreferencedInvoked) {
  99                     System.err.println("TEST PASSED: unreferenced() invoked");
 100                 } else {
 101                     throw new RuntimeException(
 102                         "TEST FAILED: unrefereced() not invoked after " +
 103                         ((double) TIMEOUT / 1000.0) + " seconds");
 104                 }
 105             }
 106 
 107         } catch (Exception e) {
 108             if (e instanceof RuntimeException) {
 109                 throw (RuntimeException) e;
 110             } else {
 111                 throw new RuntimeException(
 112                     "TEST FAILED: unexpected exception: " + e.toString());
 113             }
 114         } finally {
 115             /*
 116              * When all is said and done, try to unexport the remote object
 117              * so that the VM has a chance to exit.
 118              */
 119             try {
 120                 UnicastRemoteObject.unexportObject(obj, true);
 121             } catch (RemoteException e) {
 122             }
 123         }
 124     }
 125 }