[rules-users] Multi Access to Stateful Session

[gboro54]

I have a stateful session which is having objects inserted and updated from
multiple threads. The thread managing the session is using the fireUntilHalt
method as below:

	@Override
	public void run() {
		if (logger.isDebugEnabled()) {
			logger.debug("Starting session...");
		}
		threadName = Thread.currentThread().getName();
		session.fireUntilHalt();
	}


The code being invoked to insert/modify objects is below:
	public synchronized void insertOrUpdate(Object fact) {

		Preconditions.checkNotNull(fact);
		FactHandle factHandle = session.getFactHandle(fact);

		if (factHandle == null) {
			session.insert(fact);
		} else {
			session.update(factHandle, fact);
		}

	}

The problem I am running into is that I have a control fact which keeps an
internal counter(messages coming in are sequenced and need to be processed
in order) and a list of "deregister  messages"(messages that are not going
to be inserted for various reasons). The problem I am having is that 75% of
the time it seems something goes wrong with the counter and messages stop
being processed and build up in the session. If i pass every message in and
don't try and deregister any everything works ok. The rules I have for
working with the message deregister is as follows(this is a an example there
are will be other rules added eventually):
rule "Dereg Message"
	salience 10000
	when
	
$controller:MessageControl($pos:currentPosition,excludedPositions[$pos]!=null)
	then
		modify( $controller ){
        	moveCurrentPositionForward(1)
    	}
end



rule "Remove Message"
	salience -15000
	when
	
$controller:MessageControl($pos:currentPosition,excludedPositions[$pos]==null)
		$tsc:Message(rank==$pos)
	
	then
		cdiEvent.fire(new CDIEvent($tsc));
		retract($tsc);
		modify( $controller ){
        	moveCurrentPositionForward(1)
    	}
end

The controller class is:

	private BigInteger currentPosition = new BigInteger("0");
	private Map<BigInteger, BigInteger> excludedPositions = new
ConcurrentHashMap<BigInteger, BigInteger>();

	public synchronized void addPositionToExclusionList(BigInteger position) {
		excludedPositions.put(position, position);
	}

	public synchronized BigInteger getCurrentPosition() {
		return currentPosition;
	}

	public synchronized void moveCurrentPositionForward(Integer value) {
		currentPosition = currentPosition.add(new BigInteger(value.toString()));
	}

	public synchronized Map<BigInteger, BigInteger> getExcludedPositions() {
		return excludedPositions;
	}

	public synchronized Collection<BigInteger> getExclusionList() {
		return excludedPositions.values();
	}

Any thoughts to why this may be occuring? I have been banging my head on
this problem for a couple days.  We are using drools 5.3 


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