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*
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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
/* @test
* @bug 4017232 8046339
* @summary If, after returning a reference to a remote object in the current
* VM (which gets implicitly converted to a remote stub), the client fails to
* both send a DGC dirty call and to send a "DGC acknowledgment", the RMI
* runtime should eventually allow the remote object to be garbage collected,
* rather than pinning it indefinitely.
* @author Peter Jones
*
* @modules java.rmi/sun.rmi.transport:+open
* @build DGCAckFailure DGCAckFailure_Stub
* @run main/othervm DGCAckFailure
*/
import java.io.*;
import java.net.*;
import java.lang.reflect.Field;
import java.lang.ref.*;
import java.rmi.*;
import java.rmi.server.*;
import java.util.Map;
import sun.rmi.transport.DGCAckHandler;
interface ReturnRemote extends Remote {
Object returnRemote() throws RemoteException;
}
public class DGCAckFailure implements ReturnRemote {
private static final long TIMEOUT = 20000;
private static final long ACK_TIMEOUT = TIMEOUT / 2;
public Object returnRemote() {
return new Wrapper(this);
}
public static void main(String[] args) throws Exception {
System.setProperty("sun.rmi.dgc.ackTimeout",
Long.toString(ACK_TIMEOUT));
/*
* Set a socket factory that has a hook for shutting down all client
* output (writes from client-created sockets and new connection
* attempts). We then use this hook right before a remote stub gets
* deserialized, so that the client will not be able to send a DGC
* dirty call, or a DGC acknowledgment. Without the DGC ack, we
* hope that the RMI runtime will still eventually allow the remote
* object to be garbage collected.
*/
RMISocketFactory.setSocketFactory(new TestSF());
System.err.println("test socket factory set");
Remote impl = new DGCAckFailure();
ReferenceQueue refQueue = new ReferenceQueue();
Reference weakRef = new WeakReference(impl, refQueue);
ReturnRemote stub =
(ReturnRemote) UnicastRemoteObject.exportObject(impl);
System.err.println("remote object exported; stub = " + stub);
try {
Object wrappedStub = stub.returnRemote();
System.err.println("invocation returned: " + wrappedStub);
impl = null;
stub = null; // in case 4114579 ever gets fixed
System.err.println("strong references to impl cleared");
System.err.println("waiting for weak reference notification:");
Reference ref = null;
for (int i = 0; i < 6; i++) {
System.gc();
ref = refQueue.remove(TIMEOUT / 5);
if (ref != null) {
break;
}
}
if (ref != weakRef) {
throw new RuntimeException("TEST FAILED: " +
"timed out, remote object not garbage collected");
}
// 8046339
// All DGCAckHandlers must be properly released after timeout
Thread.sleep(ACK_TIMEOUT + 100);
try {
Field field =
DGCAckHandler.class.getDeclaredField("idTable");
field.setAccessible(true);
Object obj = field.get(null);
Map<?,?> idTable = (Map<?,?>)obj;
if (!idTable.isEmpty()) {
throw new RuntimeException("TEST FAILED: " +
"DGCAckHandler.idTable isn't empty");
}
} catch (ReflectiveOperationException roe) {
throw new RuntimeException(roe);
}
System.err.println("TEST PASSED");
} finally {
try {
UnicastRemoteObject.unexportObject((Remote) weakRef.get(),
true);
} catch (Exception e) {
}
}
}
private static class Wrapper implements Serializable {
private final Remote obj;
Wrapper(Remote obj) { this.obj = obj; }
private void readObject(ObjectInputStream in)
throws IOException, ClassNotFoundException
{
TestSF.shutdownClientOutput();
System.err.println(
"Wrapper.readObject: SHUTTING DOWN CLIENT OUTPUT");
in.defaultReadObject();
}
public String toString() { return "Wrapper[" + obj + "]"; }
}
private static class TestSF extends RMISocketFactory {
private static volatile boolean shutdown = false;
static void shutdownClientOutput() { shutdown = true; }
public Socket createSocket(String host, int port) throws IOException {
if (shutdown) {
IOException e = new java.net.ConnectException(
"test socket factory rejecting client connection");
System.err.println(e);
// e.printStackTrace();
throw e;
} else {
return new TestSocket(host, port);
}
}
public ServerSocket createServerSocket(int port) throws IOException {
return new ServerSocket(port);
}
private static class TestSocket extends Socket {
TestSocket(String host, int port) throws IOException {
super(host, port);
}
public OutputStream getOutputStream() throws IOException {
return new TestOutputStream(super.getOutputStream());
}
}
private static class TestOutputStream extends FilterOutputStream {
TestOutputStream(OutputStream out) { super(out); }
public void write(int b) throws IOException {
if (shutdown) {
IOException e = new IOException(
"connection broken by test socket factory");
System.err.println(e);
// e.printStackTrace();
throw e;
} else {
super.write(b);
}
}
}
}
}