Hi, I'm trying to move MarshalledValue to use an injected Marshaller rather than relying on standard serialization and this is causing me a small problem: One of the trade offs when making JBoss Marshalling marshaller/unmarshaller a thread local in JBoss Marshaller is reentrancy. When marshalling a MarshalledValue, we call start() on the marshaller and then we'd call marshallerValue.getRaw(). The most reasonable implementation using an injected marshaller would call: raw = marshaller.objectToBuffer(instance).getBuf(); By calling oTB again, you're calling start on the marshaller below and since this is a thread local, this is exactly the same instance and you get issues. I don't think JBoss Marshalling marshaller/unmarshaller are meant to be reentrant and this is not my intention. A second option would be to simply create a new marshaller in MarshalledValue.getRaw() but this means some initialisation that involves reflection, so this is no good. The third option, an my preferred one, would be to add a boolean parameter to Marshaller.startObjectOutput() called cached. Based on this parameter, you could either get the marshaller from the thread local or if false, get a new one from the factory. This would get around the issue and makes the API more flexible coping with reentrant marshalling while for the rest of cases, taking advantage of the performance gains from using thread locals. The code in marshallerValue.getRaw() would then look like this: ExposedByteArrayOutputStream baos = new ExposedByteArrayOutputStream(128); ObjectOutput out = marshaller.startObjectOutput(baos, false); try { marshaller.objectToObjectStream(instance); } finally { marshaller.finishObjectOutput(out); } raw = baos.getRawBuffer(); Of course, I would document this accordingly in the API so that cached is only set to false if reentrant marshalling could happen. Thoughts? -- Galder Zamarreño Sr. Software Maintenance Engineer JBoss, a division of Red Hat