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.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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).
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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
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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
46import java.rmi.*;
47import java.rmi.registry.*;
48import java.rmi.server.*;
49
50public 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}
126