| /* |
| * Copyright (c) 1998, 2017, 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. |
| */ |
| |
| /* @test |
| * @bug 4094891 8157777 |
| * @summary unable to retry call if cached connection to server is used |
| * @library ../../../../java/rmi/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 RegistryVM RegistryRunner |
| * @run main/othervm DeadCachedConnection |
| */ |
| |
| /* Fault: Cached connections used for remote invocations exhibited |
| * failure (sudden EOF or a TCP-related exception) immediately on |
| * sending a new request. It was then impossible to tell whether the |
| * connection had managed to transport the request before dying; even |
| * deserialization of request arguments is non-idempotent in general. |
| * |
| * In fact, this problem cannot be solved generally without rewriting |
| * the protocol. For now, the common case is the closing of an idle |
| * connection by a loaded/bored/dead server host. |
| * |
| * The fix is/was to trivially attempt to execute a non-blocking read |
| * on the connection before reusing it, to see if an exception/EOF is |
| * waiting for delivery. This is a 99%/1% solution, but until the |
| * great protocol rewrite, it's the best option. |
| * |
| * Reproducing is by establishing a connection to a registry and |
| * killing/restarting that registry (this forces the TCP connection |
| * to close). The next call to the registry will use the (stale) |
| * cached connection, and will fail without the bugfix. |
| */ |
| |
| import java.io.*; |
| import java.rmi.*; |
| import java.rmi.registry.*; |
| import java.rmi.server.*; |
| |
| public class DeadCachedConnection { |
| |
| static public void main(String[] argv) |
| throws Exception { |
| try { |
| Registry reg = null; |
| int port = makeRegistry(0); |
| |
| // Get a handle to the registry |
| System.err.println ("Locating just-started registry..."); |
| try { |
| reg = LocateRegistry.getRegistry(port); |
| } catch (RemoteException e) { |
| throw new InternalError ("Can't find registry after starting it."); |
| } |
| |
| // Contact the registry by invoking something on it. |
| System.err.println ("Connecting to registry..."); |
| String[] junk = reg.list(); |
| |
| // Kill and restart the registry |
| System.err.println("Killing registry..."); |
| killRegistry(); |
| System.err.println("Restarting registry..."); |
| makeRegistry(port); |
| |
| // Try again (this is the test) |
| System.err.println("Trying to use registry in spite of stale cache..."); |
| junk = reg.list(); |
| |
| System.err.println("Test succeeded."); |
| } catch (Exception e) { |
| TestLibrary.bomb(e); |
| } finally { |
| // dont leave the registry around to affect other tests. |
| killRegistry(); |
| } |
| } |
| |
| public static int makeRegistry(int port) { |
| try { |
| subreg = RegistryVM.createRegistryVM(System.out, System.err, "", port); |
| subreg.start(); |
| int regPort = subreg.getPort(); |
| System.out.println("Starting registry on port " + regPort); |
| return regPort; |
| } catch (IOException e) { |
| // one of these is summarily dropped, can't remember which one |
| System.out.println ("Test setup failed - cannot run rmiregistry"); |
| TestLibrary.bomb("Test setup failed - cannot run test", e); |
| } |
| return -1; |
| } |
| |
| private static RegistryVM subreg = null; |
| |
| public static void killRegistry() throws InterruptedException { |
| if (subreg != null) { |
| subreg.cleanup(); |
| subreg = null; |
| } |
| } |
| } |