test/java/rmi/server/Unreferenced/leaseCheckInterval/LeaseCheckInterval.java

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 * version 2 for more details (a copy is included in the LICENSE file that
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/* @test
 * @bug 4285878
 * @summary When the "java.rmi.dgc.leaseValue" system property is set to a
 * value much lower than its default (10 minutes), then the server-side
 * user-visible detection of DGC lease expiration-- in the form of
 * Unreferenced.unreferenced() invocations and possibly even local garbage
 * collection (including weak reference notification, finalization, etc.)--
 * may be delayed longer than expected.  While this is not a spec violation
 * (because there are no timeliness guarantees for any of these garbage
 * collection-related events), the user might expect that an unreferenced()
 * invocation for an object whose last client has terminated abnorally
 * should occur on relatively the same time order as the lease value
 * granted.
 * @author Peter Jones
 *
 * @library ../../../testlibrary
 * @build TestLibrary
 * @build JavaVM
 * @build LeaseCheckInterval
 * @build LeaseCheckInterval_Stub
 * @build SelfTerminator
 * @run main/othervm LeaseCheckInterval
 */

import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
import java.rmi.server.Unreferenced;

public class LeaseCheckInterval implements Remote, Unreferenced {

    public static final String BINDING = "LeaseCheckInterval";
    private static final long LEASE_VALUE = 10000;
    private static final long TIMEOUT = 20000;

    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) throws Exception {

        System.err.println("\nRegression test for bug 4285878\n");

        /*
         * Set the duration of leases granted to a very small value, so that
         * we can test if expirations are detected in a roughly comparable
         * time.
         */
        System.setProperty("java.rmi.dgc.leaseValue",
                           String.valueOf(LEASE_VALUE));

        LeaseCheckInterval obj = new LeaseCheckInterval();

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

            Registry localRegistry =
                LocateRegistry.createRegistry(TestLibrary.REGISTRY_PORT);
            System.err.println("created local registry");

            localRegistry.bind(BINDING, obj);
            System.err.println("bound remote object in local registry");

            synchronized (obj.lock) {
                System.err.println("starting remote client VM...");
                (new JavaVM("SelfTerminator")).start();

                System.err.println("waiting for unreferenced() callback...");
                obj.lock.wait(TIMEOUT);

                if (obj.unreferencedInvoked) {
                    System.err.println("TEST PASSED: " +
                        "unreferenced() invoked in timely fashion");
                } else {
                    throw new RuntimeException(
                        "TEST FAILED: unreferenced() 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) {
            }
        }
    }
}