Optimistic Locking Scheme: Occasional IllegalStateExceptions on commit ---------------------------------------------------------------------- Key: JBCACHE-740 URL: http://jira.jboss.com/jira/browse/JBCACHE-740 Project: JBoss Cache Issue Type: Bug Security Level: Public (Everyone can see) Affects Versions: 1.4.0 Environment: Linux 2.6.15-26-686 #1 SMP PREEMPT Thu Aug 3 03:13:28 UTC 2006 i686 GNU/Linux java version "1.5.0_06" Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05) Java HotSpot(TM) Client VM (build 1.5.0_06-b05, mixed mode, sharing) JOTM 2.0.10 JUnit 3.8.1 Reporter: Carsten Krebs Assigned To: Manik Surtani Fix For: 2.0.0 The unit test below reproduces "occasional" IllegalStateExceptions (s.b.) on commiting a transaction. This test tries to modify the same node at the same time by different threads in different transactions using the optimistic locking scheme. java.lang.IllegalStateException: there is already a writer holding the lock: GlobalTransaction:<null>:43 at org.jboss.cache.lock.LockMap.setWriterIfNotNull(LockMap.java:96) at org.jboss.cache.lock.IdentityLock.acquireWriteLock(IdentityLock.java:204) at org.jboss.cache.Node.acquireWriteLock(Node.java:431) at org.jboss.cache.Node.acquire(Node.java:386) at org.jboss.cache.interceptors.OptimisticLockingInterceptor.lockNodes(OptimisticLockingInterceptor.java:149) at org.jboss.cache.interceptors.OptimisticLockingInterceptor.invoke(OptimisticLockingInterceptor.java:76) at org.jboss.cache.interceptors.Interceptor.invoke(Interceptor.java:68) at org.jboss.cache.interceptors.TxInterceptor.runPreparePhase(TxInterceptor.java:804) at org.jboss.cache.interceptors.TxInterceptor$LocalSynchronizationHandler.beforeCompletion(TxInterceptor.java:1069) at org.jboss.cache.interceptors.OrderedSynchronizationHandler.beforeCompletion(OrderedSynchronizationHandler.java:75) at org.objectweb.jotm.SubCoordinator.doBeforeCompletion(SubCoordinator.java:1487) at org.objectweb.jotm.SubCoordinator.commit_one_phase(SubCoordinator.java:416) at org.objectweb.jotm.TransactionImpl.commit(TransactionImpl.java:239) at OptimisticLockingTest$Worker.run(OptimisticLockingTest.java:135) The Cache Config: ------------------------- <?xml version="1.0" encoding="UTF-8"?> <server> <mbean code="org.jboss.cache.TreeCache" name="jboss.cache:service=TreeCache"> <attribute name="NodeLockingScheme">OPTIMISTIC</attribute> <attribute name="CacheMode">LOCAL</attribute> </mbean> </server> The Unit Test: ------------------- import javax.transaction.Transaction; import javax.transaction.TransactionManager; import junit.framework.TestCase; import org.jboss.cache.CacheException; import org.jboss.cache.PropertyConfigurator; import org.jboss.cache.TransactionManagerLookup; import org.jboss.cache.TreeCache; import org.objectweb.jotm.Current; import EDU.oswego.cs.dl.util.concurrent.CyclicBarrier; /** * OptimisticLockingTest */ public class OptimisticLockingTest extends TestCase { private static final String NODE_PATH = "/path/node"; private static final String KEY = "key"; private static final Current jotm = new Current(); private TreeCache cache; protected void setUp() throws Exception { super.setUp(); cache = new TreeCache(); final PropertyConfigurator config = new PropertyConfigurator(); cache.setTransactionManagerLookup(new TransactionManagerLookup() { public TransactionManager getTransactionManager() throws Exception { return Current.getTransactionManager(); } }); config.configure(cache, this.getClass().getResourceAsStream( "/cache-config.xml")); cache.startService(); } public void testSimultanWrite() throws Exception { for (int i = 2; i < 20; i++) { System.out.println(">> testing simultaneous writes with " + i + " threads..."); testSimultanWrite(i); } } public void testSimultanWrite(final int _numThreads) throws Exception { final CyclicBarrier barrier = new CyclicBarrier(_numThreads); Worker[] workers = new Worker[_numThreads]; for (int i = 0; i < workers.length; i++) { workers[i] = new Worker(); workers[i].barrier = barrier; workers[i].value = "worker" + i; if (i == 0) { workers[i].isMaster = true; } workers[i].start(); } for (int i = 0; i < workers.length; i++) { workers[i].join(); } assertNull(workers[0].exception); for (int i = 0; i < workers.length; i++) { assertNull("rollback failed", workers[i].rollbackException); } for (int i = 1; i < workers.length; i++) { assertNotNull("missing exception", workers[i].exception); assertTrue("exception is not of type CacheException", workers[i].exception.getCause() instanceof CacheException); } assertEquals("worker0", cache.get(NODE_PATH, KEY)); cache.getTransactionManager().begin(); cache.remove(NODE_PATH); cache.getTransactionManager().commit(); } private class Worker extends Thread { private CyclicBarrier barrier; private Exception exception; private Exception rollbackException; private String value; private boolean isMaster; /** * @see java.lang.Thread#run() */ public void run() { final TransactionManager txManager = cache.getTransactionManager(); Transaction tx = null; try { // wait for all threads started barrier.barrier(); if (isMaster) { txManager.begin(); cache.put(NODE_PATH, KEY, value); // lets the other threads start writing barrier.barrier(); // wait for other threads to their modification barrier.barrier(); // commit first tx = txManager.getTransaction(); tx.commit(); // lets the other threads commit barrier.barrier(); } else { // wait for master to start transaction barrier.barrier(); txManager.begin(); cache.put(NODE_PATH, KEY, value); // signal modification barrier.barrier(); // wait for master to commit transaction barrier.barrier(); tx = txManager.getTransaction(); tx.commit(); } } catch (Exception e) { exception = e; try { tx.rollback(); } catch (Exception e1) { rollbackException = e1; } } } } } -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.jboss.com/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira