Thread safety?

[mfrost]

We are planning to use the TreeCache in our clustered production JBoss environment.

We will be invoking the TreeCache methods (via JMX MBean) from a Stateless Session Bean.

Are there any threading issues to consider? We have currently not placed any synchronization around any method calls to TreeCache.

Many thanks.

mark

Code example from SLSB:

 public void put(String cacheSystemName, CacheKey key, VersionedXml value) throws CacheException {
 log4j.debug("TreeCache.put()");

 //put into cache
 Fqn fqn = new Fqn(this.rootFqn, ((FqnCacheKey) key).getFqn());
 Object[] args = new Object[] {fqn, STANDARD_KEY, value};
 String[] sig = new String[] {FQN_CLASS_NAME, OBJECT_CLASS_NAME, OBJECT_CLASS_NAME};

 //Invoke the put() method
 _invoke("put", args, sig);
 }

 private Object _invoke(String methodName, Object[] args, String[] sig) throws CacheException {
 try {
 return JBossUtils.locateJBoss().invoke(cacheService, methodName, args, sig);
 } catch (Exception ex) {
 throw new CacheException("Error invoking method " + methodName + " on TreeCache", ex);
 }
 }

[belaban]

You should be fine; TreeCache is thread-safe.
Bela

[mfrost]

many thanks bela

mark

[visionlink]

there are two queues in a Region: nodeQueue and eventQueue. i understand that the BoundedBuffer is thread-safe. however, since there are two queues that are being operated on, it seems like there is a potential race in Region.putNodeEvent and LRUAlgorithm.processQueues. is there a bit of higher-level synchronization going on that i don't see?

thanks for any insight.

[ben.wang]

This is indeed a potential problem that I have been planned to correct. :-) Anway, I have just refactored the eviction policy part and checked them into jboss-head. The fix will be available in release 1.1.

Thanks,

-Ben