jdk/test/java/rmi/server/Unreferenced/finiteGCLatency/FiniteGCLatency.java

/* 
 * Copyright 1998 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

/* @test
 * @bug 4164696
 * @summary The local garbage collector needs to inspect a client VM's heap
 * often enough (even if the VM is idle) to detect unreachable live remote
 * references, so that their server VMs can be informed that the client VM
 * is no longer holding a reference; this facilitates the server VM invoking
 * the remote object's unreferenced() method (if present), garbage collecting
 * the remote object, and allowing the server VM to exit.  This test focuses
 * on the unreferenced() method being invoked: it tests that the callback
 * method will be invoked within a reasonable time after the remote object is
 * no longer remotely reachable.
 * @author Peter Jones
 *
 * @library ../../../testlibrary
 * @build FiniteGCLatency
 * @build FiniteGCLatency_Stub
 * @run main/othervm/timeout=120 FiniteGCLatency
 */

import java.rmi.*;
import java.rmi.registry.*;
import java.rmi.server.*;

public class FiniteGCLatency implements Remote, Unreferenced {

    private final static String BINDING = "FiniteGCLatency";
    private final static long GC_INTERVAL = 6000;
    private final static long TIMEOUT = 50000;

    private Object lock = new Object();
    private boolean unreferencedInvoked = false;

    public void unreferenced() {
	System.err.println("unreferenced() method invoked");
	synchronized (lock) {
	    unreferencedInvoked = true;
	    lock.notify();
	}
    }

    public static void main(String[] args) {

	System.err.println("\nRegression test for bug 4164696\n");

	/*
	 * Set the interval that RMI will request for GC latency (before RMI
	 * gets initialized and this property is read) to an unrealistically
	 * small value, so that this test shouldn't have to wait too long.
	 */
	System.setProperty("sun.rmi.dgc.client.gcInterval",
	    String.valueOf(GC_INTERVAL));

	FiniteGCLatency obj = new FiniteGCLatency();

	try {
	    UnicastRemoteObject.exportObject(obj);
	    System.err.println("exported remote object");

	    LocateRegistry.createRegistry(TestLibrary.REGISTRY_PORT);
	    System.err.println("created registry");

	    Registry registry = LocateRegistry.getRegistry("", TestLibrary.REGISTRY_PORT);
	    registry.bind(BINDING, obj);
	    System.err.println("bound remote object in registry");

	    synchronized (obj.lock) {
		registry.unbind(BINDING);
		System.err.println("unbound remote object from registry; " +
		    "waiting for unreferenced() callback...");
		obj.lock.wait(TIMEOUT);

		if (obj.unreferencedInvoked) {
		    System.err.println("TEST PASSED: unreferenced() invoked");
		} else {
		    throw new RuntimeException(
			"TEST FAILED: unrefereced() not invoked after " +
			((double) TIMEOUT / 1000.0) + " seconds");
		}
	    }

	} catch (Exception e) {
	    if (e instanceof RuntimeException) {
		throw (RuntimeException) e;
	    } else {
		throw new RuntimeException(
		    "TEST FAILED: unexpected exception: " + e.toString());
	    }
	} finally {
	    /*
	     * When all is said and done, try to unexport the remote object
	     * so that the VM has a chance to exit.
	     */
	    try {
		UnicastRemoteObject.unexportObject(obj, true);
	    } catch (RemoteException e) {
	    }
	}
    }
}