jdk-24/test/jdk/java/rmi/transport/dgcDeadLock/DGCDeadLock.java

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/* @test
 * @bug 4118056
 * @key intermittent
 *
 * @summary synopsis: Distributed Garbage Collection Deadlock
 * @author Laird Dornin
 *
 * @library ../../testlibrary
 * @modules java.rmi/sun.rmi.registry
 *          java.rmi/sun.rmi.server
 *          java.rmi/sun.rmi.transport
 *          java.rmi/sun.rmi.transport.tcp
 * @build TestLibrary Test TestImpl RegistryVM RegistryRunner
 * @run main/othervm/timeout=360 DGCDeadLock
 */

/* This test attempts to cause a deadlock between the rmi leaseChecker
 * thread and a thread that is servicing a dgc clean call. Before the
 * fix for this bug was implemented, deadlock could occur when the
 * leaseChecker held the lock on the lease table and the clean thread
 * held the lock on a target x. The clean thread would attempt to get
 * the lock on the leaseTable to do DGCImpl.unregisterTarget and the
 * leaseChecker would attempt to get the lock on x to do
 * Target.vmidDead.  Each thread held a resource that the other thread
 * was attempting to lock.
 *
 * This test causes the above conditions to occur and waits to see if
 * a given set of remote calls finishes "quickly enough."
 */

import java.rmi.*;
import java.io.*;

public class DGCDeadLock implements Runnable {
    final static public int HOLD_TARGET_TIME = 25000;
    public static final double TEST_FAIL_TIME =
            (HOLD_TARGET_TIME + 30000) * TestLibrary.getTimeoutFactor();
    public static volatile boolean finished = false;
    static final DGCDeadLock test = new DGCDeadLock();
    static volatile int registryPort = -1;

    static {
        System.setProperty("sun.rmi.transport.cleanInterval", "50");
    }

    static public void main(String[] args) {

        RegistryVM testImplVM = null;

        System.err.println("\nregression test for 4118056\n");

        try {
            String options = " --add-opens java.rmi/sun.rmi.transport=ALL-UNNAMED" +
                " -Djava.rmi.dgc.leaseValue=500000" +
                " -Dsun.rmi.dgc.checkInterval=" +
                (HOLD_TARGET_TIME - 5000);

            testImplVM = RegistryVM.createRegistryVMWithRunner("TestImpl", options);
            testImplVM.start();
            registryPort = testImplVM.getPort();

            synchronized (test) {
                Thread t = new Thread(test);
                t.setDaemon(true);
                t.start();

                // wait for the remote calls to take place
                test.wait((long)TEST_FAIL_TIME);
            }

            if (!finished) {
                TestLibrary.bomb("Test failed, had exception or exercise" +
                                           " routines took too long to " +
                                           "execute");
            }
            System.err.println("Test passed, exercises " +
                               "finished in time.");

        } catch (Exception e) {
            TestLibrary.bomb("test failed in main()", e);
        } finally {
            if (testImplVM != null) {
                testImplVM.cleanup();
                testImplVM = null;
            }
        }
    }

    public void run() {
        try {
            String echo = null;

            // create a test client
            Test foo = (Test) Naming.lookup("rmi://:" +
                                            registryPort +
                                            "/Foo");
            echo = foo.echo("Hello world");
            System.err.println("Test object created.");

            /* give TestImpl time to lock the target in the
             * object table and any dirtys finish.
             */
            Thread.currentThread().sleep(5000);

            //unreference "Foo"
            foo = null;

            //garbage collect and finalize foo
            Runtime.getRuntime().gc();
            Runtime.getRuntime().runFinalization();

            //import "Bar"
            Test bar = (Test) Naming.lookup("rmi://:" +
                                            registryPort +
                                            "/Bar");

            /* infinite loop to show the liveness of Client,
             * if we have deadlock remote call will not return
             */
            try {
                for (int i = 0; i < 500; i++) {
                    echo = bar.echo("Remote call" + i);
                    Thread.sleep(10);
                }

                // flag exercises finished
                finished = true;

            } catch (RemoteException e) {
                System.err.println("catch RemoteException");
                e.printStackTrace();
            }

        } catch (Exception e) {
            TestLibrary.bomb("test failed in run()", e);
        } finally {
            synchronized(this) {
                notify();
            }
        }
    }
}