[jira] Resolved: (JCR-2269) Possible concurrency bug with Workspace.copy()

["Stefan Guggisberg (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/JCR-2269?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Stefan Guggisberg resolved JCR-2269.
------------------------------------

    Resolution: Fixed

fixed in svn r810565.

thanks for reporting this issue and providing a test case!


> Possible concurrency bug with Workspace.copy() 
> -----------------------------------------------
>
>                 Key: JCR-2269
>                 URL: https://issues.apache.org/jira/browse/JCR-2269
>             Project: Jackrabbit Content Repository
>          Issue Type: Bug
>          Components: jackrabbit-core
>    Affects Versions: 1.6.0
>            Reporter: Jervis Liu
>         Attachments: ConcurrentCopyTest.java
>
>
> Hi,
> Enclosed below is a test case that can be used to reproduce a
> concurrency bug. This test case uses two con-current threads to
> execute Workspace.copy() to copy a node to same destination. The
> parent node has set its allowSameNameSiblings to false. According to
> the javadoc of Workspace.copy(String srcAbsPath, String destAbsPath) :
> "This method copies the node at srcAbsPath to the new location at
> destAbsPath. If successful, the change is persisted immediately, there
> is no need to call save.".  "An ItemExistException is thrown if a
> property already exists at destAbsPath or a node already exist there,
> and same name siblings are not allowed. "
> However in reality this is not the case.  The test case can end up
> with two child nodes with same names. Please note, not every run can
> reproduce the problem, but generally I can get the problem within 3 to
> 10 iterations. I also got an InvalidItemStateException once (only
> once).  Can someone kindly help to confirm if this is a bug in
> Jackrabbit or maybe I am using JackRabbit in a wrong way? The test
> case has been tested on Jackrabbit 1.6 branch
> (http://svn.apache.org/repos/asf/jackrabbit/tags/1.6.0), Windows
> Vista, JDK 1.5.0_14.
> The test case is also attached for your convenience.
> Thanks,
> Jervis Liu
> package org.apache.jackrabbit.core;
> import org.apache.jackrabbit.test.AbstractJCRTest;
> import javax.jcr.ItemExistsException;
> import javax.jcr.Node;
> import javax.jcr.Session;
> import javax.jcr.Value;
> import javax.jcr.NodeIterator;
> import java.util.Random;
> import java.util.ArrayList;
> import java.util.Iterator;
> import javax.jcr.nodetype.NodeType;
> import org.apache.jackrabbit.test.NotExecutableException;
> import javax.jcr.RepositoryException;
> import javax.jcr.nodetype.NodeTypeManager;
> public class ConcurrentCopyTest extends AbstractJCRTest {
>     private static final int NUM_ITERATIONS = 40;
>     private static final int NUM_SESSIONS = 2;
>     String sourcePath;
>     String destPath;
>     public void testConcurrentCopy() throws Exception {
>         for (int n = 0; n < NUM_ITERATIONS; n++) {
>             System.out.println("---Iteration---- " + n);
>             // clean up testRoot first
>             if (testRootNode.hasNode("ConcurrentCopyTestNode")) {
>                 Node testNode = testRootNode.getNode("ConcurrentCopyTestNode");
>                 testNode.remove();
>                 testRootNode.save();
>                 System.out.println("---old node removed---");
>             }
>             // create a parent node where allowSameNameSiblings is set to false
>             Node snsfNode = testRootNode.addNode("ConcurrentCopyTestNode",
>                     "nt:folder");
>             testRootNode.save();
>             sourcePath = snsfNode.getPath();
>             destPath = sourcePath + "/" + "CopiedFromConcurrentCopyTestNode";
>             System.out.println("---sourcePath-----------------" + sourcePath);
>             System.out.println("---destPath-----------------" + destPath);
>             // firstly we verify it works with single thread.
>             Session rootSession = helper.getSuperuserSession();
>             rootSession.getWorkspace().copy(sourcePath, destPath + "test");
>             // copy again to same destPath, expect an ItemExistsException
>             try {
>                 rootSession.getWorkspace().copy(sourcePath, destPath + "test");
>                 fail("Node exists below '" + destPath + "'. Test should fail.");
>             } catch (ItemExistsException e) {
>             }
>             Thread[] threads = new Thread[NUM_SESSIONS];
>             for (int i = 0; i < threads.length; i++) {
>                 // create new session
>                 Session session = helper.getSuperuserSession();
>                 TestSession ts = new TestSession("s" + i, session);
>                 Thread t = new Thread(ts);
>                 t.setName((NUM_ITERATIONS - n) + "-s" + i);
>                 t.start();
>                 log.println("Thread#" + i + " started");
>                 threads[i] = t;
>                 // Thread.yield();
>                 // Thread.sleep(100);
>             }
>             for (int i = 0; i < threads.length; i++) {
>                 threads[i].join();
>             }
>             NodeIterator results = testRootNode.getNode(
>                     "ConcurrentCopyTestNode").getNodes(
>                     "CopiedFromConcurrentCopyTestNode");
>             while (results.hasNext()) {
>                 Node node = results.nextNode();
>                 System.out.println("--result node- " + node.getName());
>             }
>             assertEquals(1, results.getSize());
>         }
>     }
>     // --------------------------------------------------------< inner classes >
>     class TestSession implements Runnable {
>         Session session;
>         String identity;
>         Random r;
>         TestSession(String identity, Session s) {
>             session = s;
>             this.identity = identity;
>             r = new Random();
>         }
>         private void randomSleep() {
>             long l = r.nextInt(90) + 20;
>             try {
>                 Thread.sleep(l);
>             } catch (InterruptedException ie) {
>             }
>         }
>         public void run() {
>             log.println("started.");
>             String state = "";
>             try {
>                 this.session.getWorkspace().copy(sourcePath, destPath);
>                 session.save();
>                 Node newNode =
> testRootNode.getNode("ConcurrentCopyTestNode/CopiedFromConcurrentCopyTestNode");
>                 System.out.println("--Added node- " + newNode.getName());
>                 session.save();
>                 randomSleep();
>             } catch (Exception e) {
>                 log.println("Exception while " + state + ": " + e.getMessage());
>                 e.printStackTrace();
>             } finally {
>                 session.logout();
>             }
>             log.println("ended.");
>         }
>     }
> }

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.