EMF model transaction - eclipse-emf

Question

In our project we use an implementation of HL7 document from openehealth. This implementation uses EMF as primitive model and delegates all calls to EMF. We need to handle a large volume of documents and our flows involve concurrent processing of documents(read, validate, query). In concurrency environment the EMF layer crashes with UnsupportedOperationException. From openehealth site it says to handle the synchronized processing in the client api, but this will decrease our system performance and we don't want this. I tried EMF transaction API, TransactionalEditingDomain, which says that supports read only model transactions but without success. My test looks something like this:
ExecutorService executorService = Executors.newFixedThreadPool(4);
final List<ClinicalDocument> documents = new ArrayList<ClinicalDocument>();
for (int i = 0; i < 100; i ++) {
executorService.submit(new Runnable() {
#Override
public void run() {
try {
int randomNum = 1 + (int)(Math.random()*6);
ClinicalDocument cda = readCda();
processIntensiveWork(cda);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
private void processIntensiveWork(final ClinicalDocument document) {
for (final Method method : document.getClass().getMethods())
if (method.getName().startsWith("get")) {
try {
domain.runExclusive(new RunnableWithResult.Impl() {
#Override
public void run() {
try {
method.invoke(document);
System.out.println("Invoked method: " + method.getName());
setResult(null);
} catch (UnsupportedOperationException e) {
e.printStackTrace();
}catch (Exception e){
e.printStackTrace();
}
}
});
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
For this test case we frequently caught java.lang.UnsupportedOperationException.
I mention that for some test cases i also caught the the following error from EMF transaction API: java.lang.IllegalArgumentException: Can only deactivate the active transaction
Any suggestions are kindly appreciated. Feel free to ask other information that might help you in resolving the problem.