/*
* Copyright (c) 1998, 2012, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
*/
import java.rmi.*;
import sun.rmi.transport.*;
import sun.rmi.*;
import java.io.*;
import java.lang.reflect.*;
import java.rmi.dgc.*;
import java.util.*;
import java.rmi.registry.*;
import java.rmi.server.*;
public class TestImpl extends UnicastRemoteObject
implements Test {
static Thread locker = null;
static TestImpl foo = null;
static TestImpl bar = null;
TestImpl() throws RemoteException {
}
public String echo(String msg) throws RemoteException {
if (locker == null) {
// hold the target if not already held
locker = lockTargetExpireLeases(foo, DGCDeadLock.HOLD_TARGET_TIME);
}
return "Message received: " + msg;
}
static public void main(String[] args) {
Registry registry = null;
try {
int registryPort = Integer.parseInt(System.getProperty("rmi.registry.port"));
registry = java.rmi.registry.LocateRegistry.
createRegistry(registryPort);
//export "Foo"
foo = new TestImpl();
Naming.rebind("rmi://:" +
registryPort
+ "/Foo", foo);
try {
//export "Bar" after leases have been expired.
bar = new TestImpl();
Naming.rebind("rmi://localhost:" +
registryPort
+ "/Bar", bar);
} catch (Exception e) {
throw new RemoteException(e.getMessage());
}
Thread.sleep(DGCDeadLock.TEST_FAIL_TIME);
System.err.println("object vm exiting...");
System.exit(0);
} catch (Exception e) {
System.err.println(e.getMessage());
e.printStackTrace();
} finally {
TestLibrary.unexport(registry);
registry = null;
}
}
static Thread lockTargetExpireLeases(Remote toLock, int timeOut) {
Thread t = new Thread((Runnable) new TargetLocker(toLock, timeOut));
t.start();
return t;
}
static class TargetLocker implements Runnable {
Remote toLock = null;
int timeOut = 0;
TargetLocker(Remote toLock, int timeOut) {
this.toLock = toLock;
this.timeOut = timeOut;
}
public void run() {
try {
// give dgc dirty calls time to finish.
Thread.currentThread().sleep(4000);
java.security.AccessController.
doPrivileged(new LockTargetCheckLeases(toLock,
timeOut));
} catch (Exception e) {
System.err.println(e.getMessage());
e.printStackTrace();
System.exit(1);
}
}
}
static class LockTargetCheckLeases
implements java.security.PrivilegedAction {
Remote toLock = null;
int timeOut = 0;
LockTargetCheckLeases(Remote toLock, int timeOut) {
this.toLock = toLock;
this.timeOut = timeOut;
}
public Object run() {
try {
Class args[] = new Class[1];
Class objTableClass = Class.forName
("sun.rmi.transport.ObjectTable");
/* get the Target that corresponds to toLock from the
* ObjectTable
*/
args[0] = Class.forName("java.rmi.Remote");
Method objTableGetTarget =
objTableClass.getDeclaredMethod("getTarget", args );
objTableGetTarget.setAccessible(true);
Target lockTarget =
((Target) objTableGetTarget.invoke
(null , new Object [] {toLock} ));
// make sure the lease on this object has expired.
expireLeases(lockTarget);
// stop other threads from using the target for toLock.
synchronized (lockTarget) {
System.err.println("Locked the relevant target, sleeping " +
timeOut/1000 + " seconds");
Thread.currentThread().sleep(timeOut);
System.err.println("Target unlocked");
}
} catch (Exception e) {
System.err.println(e.getMessage());
e.printStackTrace();
System.exit(1);
}
return null;
}
}
/* leases have long values, so no dirty calls which would lock out
* a clean call, but the leases need to expire anyway, so we do it
* explicitly.
*/
static void expireLeases(Target t) throws Exception {
final Target target = t;
java.security.AccessController.doPrivileged(
// put this into another class?
new java.security.PrivilegedAction() {
public Object run() {
try {
Class DGCClass = Class.forName("sun.rmi.transport.DGCImpl");
Method getDGCImpl =
DGCClass.getDeclaredMethod("getDGCImpl", null );
getDGCImpl.setAccessible(true);
// make sure the lease on this object has expired.
DGC dgcImpl = ((DGC) getDGCImpl.invoke(null, null));
/* Get the lease table from the DGCImpl. */
Field reflectedLeaseTable =
dgcImpl.getClass().getDeclaredField("leaseTable");
reflectedLeaseTable.setAccessible(true);
Map leaseTable = (Map) reflectedLeaseTable.get(dgcImpl);
// dont really need this synchronization...
synchronized (leaseTable) {
Iterator en = leaseTable.values().iterator();
while (en.hasNext()) {
Object info = en.next();
/* Get the notifySet in the leaseInfo object. */
Field notifySetField =
info.getClass().getDeclaredField("notifySet");
notifySetField.setAccessible(true);
HashSet notifySet = (HashSet) notifySetField.get(info);
Iterator iter = notifySet.iterator();
while (iter.hasNext()) {
Target notified = (Target) iter.next();
if (notified == target) {
/* Get and set the expiration field from the info object. */
Field expirationField = info.getClass().
getDeclaredField("expiration");
expirationField.setAccessible(true);
expirationField.setLong(info, 0);
}
}
}
}
} catch (Exception e) {
System.err.println(e.getMessage());
e.printStackTrace();
System.exit(1);
}
// no interesting return value for this privileged action
return null;
}
});
}
}