JBossDeveloper

Thanks, i didn't think of using a TM instead of a UserTransaction.
Using that, i get exactly the same behaviour as with Atomikos though:
-with pessimistic locking scheme, the test passes
-with mvcc, i get the same error:

Detected write skew on Fqn [/foo/mynode]. Another process has changed the node since we last read it!

If i comment the write-skew check, i also get the same behaviour as i did with Atomikos: no exception, but the test fails with

java.lang.AssertionError: expected:<10> but was:<2>

Good news! It works at last, both with the default TM and with Atomikos.
To make it work, i used the conf:

<locking
 isolationLevel="READ_COMMITTED"
 lockParentForChildInsertRemove="false"
 lockAcquisitionTimeout="20000"
 nodeLockingScheme="mvcc"
 writeSkewCheck="false"
 concurrencyLevel="500"/>

With JBC's default TM

The test:

public class ComportementTransactionnelTableCoreCache
{
 private Cache cache;
 protected TracksTable table = new TracksTableImpl ();
 protected final ExecutorService executorService = Executors.newCachedThreadPool();

 @Test
 public void isolation_RW_RW () throws Exception
 {
 table.initScalar ();

 int nbWriters = 10;

 CountDownLatch latch = new CountDownLatch ( nbWriters );
 for ( int i = 0 ; i < nbWriters ; i ++ )
 {
 executorService.submit ( new AsyncIncrement ( latch ) );
 }
 latch.await ();

 assertEquals ( nbWriters , table.getScalar() );
 }

 protected class AsyncIncrement implements Runnable
 {
 private final CountDownLatch latch;

 public AsyncIncrement ( CountDownLatch latch )
 {
 this.latch = latch;
 }

 @Override
 public void run()
 {
 try { table.incrementScalar (); }
 finally { latch.countDown (); }
 }
 }

 @Before
 public void before ()
 {
 cache = initPojoCache ();
 cache.start();
 table.setCache ( cache );

 table.initScalar();
 assertEquals ( 0 , table.getScalar() );
 }

 @After
 public void after ()
 {
 table.unsetCache ();
 cache.stop();
 }

 private Cache initPojoCache()
 {
 CacheFactory factory = new DefaultCacheFactory();
 Cache cache = factory.createCache("resources/META-INF/replSync-service.xml", false);
 //cache.getConfiguration().setWriteSkewCheck(true);

 cache.create();
 return cache;
 }
}

public class TracksTableImpl implements TracksTable
{
 private Cache cache;
 private int scalar;

 @Override
 public void incrementScalar()
 {
 try
 {
 TransactionManager tx = getTm ();
 tx.begin();

 cache.put("/foo/mynode", "_lockthisplease_", "_lockthisplease_");
 cache.getInvocationContext().getOptionOverrides().setForceWriteLock(true);
 int tmp = (Integer)cache.get("/foo/mynode", "scalar");
 tmp++;
 cache.put ( "/foo/mynode" , "scalar" , tmp );

 tx.commit();
 }
 catch ( Exception e )
 {
 e.printStackTrace();
 throw new RuntimeException ();
 }
 }

 @Override
 public int getScalar()
 {
 try
 {
 TransactionManager tx = getTm ();
 tx.begin();
 int ret = (Integer)cache.get("/foo/mynode", "scalar");
 tx.commit();
 return ret;
 }
 catch ( Exception e )
 {
 e.printStackTrace();
 throw new RuntimeException ();
 }
 }

 @Override
 public void initScalar()
 {
 try
 {
 TransactionManager tx = getTm ();
 tx.begin();
 cache.put ( "/foo/mynode" , "scalar" , 0 );
 tx.commit();
 }
 catch ( Exception e )
 {
 e.printStackTrace();
 throw new RuntimeException ();
 }
 }

 @Override
 public void setCache ( Cache cache )
 {
 this.cache = cache;
 }

 @Override
 public void unsetCache ()
 {
 this.cache = null;
 }

 private TransactionManager getTm()
 {
 return cache.getConfiguration().getRuntimeConfig().getTransactionManager();
 }
}

<?xml version="1.0" encoding="UTF-8"?>

<jbosscache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:jboss:jbosscache-core:config:3.2">

 <transaction transactionManagerLookupClass="org.jboss.cache.transaction.DummyTransactionManagerLookup"/>

 <!--
 isolation levels supported: READ_COMMITTED and REPEATABLE_READ
 nodeLockingSchemes: mvcc, pessimistic (deprecated), optimistic (deprecated)
 -->
 <locking
 isolationLevel="READ_COMMITTED"
 lockParentForChildInsertRemove="false"
 lockAcquisitionTimeout="20000"
 nodeLockingScheme="mvcc"
 writeSkewCheck="false"
 concurrencyLevel="500"/>

 <!-- By not specifying the 'clustering' element, the cache runs in LOCAL mode. -->

</jbosscache>

With Atomikos

The test:

public class ComportementTransactionnelTableCoreCache
{
 private Cache cache;
 protected TracksTable table = new TracksTableImpl ();
 protected final ExecutorService executorService = Executors.newCachedThreadPool();

 @Test
 public void isolation_RW_RW () throws Exception
 {
 table.initScalar ();

 int nbWriters = 10;

 CountDownLatch latch = new CountDownLatch ( nbWriters );
 for ( int i = 0 ; i < nbWriters ; i ++ )
 {
 executorService.submit ( new AsyncIncrement ( latch ) );
 }
 latch.await ();

 assertEquals ( nbWriters , table.getScalar() );
 }

 protected class AsyncIncrement implements Runnable
 {
 private final CountDownLatch latch;

 public AsyncIncrement ( CountDownLatch latch )
 {
 this.latch = latch;
 }

 @Override
 public void run()
 {
 try { table.incrementScalar (); }
 finally { latch.countDown (); }
 }
 }

 @Before
 public void before ()
 {
 cache = initPojoCache ();
 cache.start();
 table.setCache ( cache );

 table.initScalar();
 assertEquals ( 0 , table.getScalar() );
 }

 @After
 public void after ()
 {
 table.unsetCache ();
 cache.stop();
 }

 private Cache initPojoCache()
 {
 CacheFactory factory = new DefaultCacheFactory();
 Cache cache = factory.createCache("resources/META-INF/replSync-service.xml", false);

 TransactionManager tm = new com.atomikos.icatch.jta.UserTransactionManager ();
 cache.getConfiguration().getRuntimeConfig().setTransactionManager(tm);

 cache.create();
 return cache;
 }
}

public class TracksTableImpl implements TracksTable
{
 private Cache cache;
 private int scalar;

 @Override
 public void incrementScalar()
 {
 try
 {
 UserTransaction tx = getUt ();
 tx.begin();

 cache.put("/foo/mynode", "_lockthisplease_", "_lockthisplease_");
 cache.getInvocationContext().getOptionOverrides().setForceWriteLock(true);
 int tmp = (Integer)cache.get("/foo/mynode", "scalar");
 tmp++;
 cache.put ( "/foo/mynode" , "scalar" , tmp );

 tx.commit();
 }
 catch ( Exception e )
 {
 e.printStackTrace();
 throw new RuntimeException ();
 }
 }

 @Override
 public int getScalar()
 {
 try
 {
 UserTransaction tx = getUt ();
 tx.begin();
 int ret = (Integer)cache.get("/foo/mynode", "scalar");
 tx.commit();
 return ret;
 }
 catch ( Exception e )
 {
 e.printStackTrace();
 throw new RuntimeException ();
 }
 }

 @Override
 public void initScalar()
 {
 try
 {
 UserTransaction tx = getUt ();
 tx.begin();
 cache.put ( "/foo/mynode" , "scalar" , 0 );
 tx.commit();
 }
 catch ( Exception e )
 {
 e.printStackTrace();
 throw new RuntimeException ();
 }
 }

 @Override
 public void setCache ( Cache cache )
 {
 this.cache = cache;
 }

 @Override
 public void unsetCache ()
 {
 this.cache = null;
 }

 private UserTransaction getUt()
 {
 return new com.atomikos.icatch.jta.UserTransactionImp();
 }
}

<?xml version="1.0" encoding="UTF-8"?>

<jbosscache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:jboss:jbosscache-core:config:3.2">

 <!--
 isolation levels supported: READ_COMMITTED and REPEATABLE_READ
 nodeLockingSchemes: mvcc, pessimistic (deprecated), optimistic (deprecated)
 -->
 <locking
 isolationLevel="READ_COMMITTED"
 lockParentForChildInsertRemove="false"
 lockAcquisitionTimeout="20000"
 nodeLockingScheme="mvcc"
 writeSkewCheck="false"
 concurrencyLevel="500"/>

 <!-- By not specifying the 'clustering' element, the cache runs in LOCAL mode. -->

</jbosscache>

With REPEATABLE_READ (the default), it still fails in the way i posted earlier:
-if writeSkewCheck is true, i get a write skew exception
-otherwise, no exceptions but the behaviour is that of threads writing to a non-thread-safe object

Also, would it be possible to have a cache setup parameter that does the same as

cache.getCache().getInvocationContext().getOptionOverrides().setForceWriteLock(true);

Thanks for investigating the issue. I have a lot of slides to write so it might take a week before i can dig more but after that I will try your test, promised :)