/* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.camunda.bpm.engine.impl.bpmn.behavior;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.camunda.bpm.engine.impl.pvm.PvmActivity;
import org.camunda.bpm.engine.impl.pvm.PvmTransition;
import org.camunda.bpm.engine.impl.pvm.delegate.ActivityExecution;
/**
* Implementation of the Parallel Gateway/AND gateway as definined in the BPMN
* 2.0 specification.
*
* The Parallel Gateway can be used for splitting a path of execution into
* multiple paths of executions (AND-split/fork behavior), one for every
* outgoing sequence flow.
*
* The Parallel Gateway can also be used for merging or joining paths of
* execution (AND-join). In this case, on every incoming sequence flow an
* execution needs to arrive, before leaving the Parallel Gateway (and
* potentially then doing the fork behavior in case of multiple outgoing
* sequence flow).
*
* Note that there is a slight difference to spec (p. 436): "The parallel
* gateway is activated if there is at least one Token on each incoming sequence
* flow." We only check the number of incoming tokens to the number of sequenceflow.
* So if two tokens would arrive through the same sequence flow, our implementation
* would activate the gateway.
*
* Note that a Parallel Gateway having one incoming and multiple ougoing
* sequence flow, is the same as having multiple outgoing sequence flow on a
* given activity. However, a parallel gateway does NOT check conditions on the
* outgoing sequence flow.
*
* @author Joram Barrez
* @author Tom Baeyens
*/
public class ParallelGatewayActivityBehavior extends GatewayActivityBehavior {
private static Logger log = Logger.getLogger(ParallelGatewayActivityBehavior.class.getName());
public void execute(ActivityExecution execution) throws Exception {
// Join
PvmActivity activity = execution.getActivity();
List<PvmTransition> outgoingTransitions = execution.getActivity().getOutgoingTransitions();
execution.inactivate();
lockConcurrentRoot(execution);
List<ActivityExecution> joinedExecutions = execution.findInactiveConcurrentExecutions(activity);
int nbrOfExecutionsToJoin = execution.getActivity().getIncomingTransitions().size();
int nbrOfExecutionsJoined = joinedExecutions.size();
if (nbrOfExecutionsJoined==nbrOfExecutionsToJoin) {
// Fork
log.fine("parallel gateway '"+activity.getId()+"' activates: "+nbrOfExecutionsJoined+" of "+nbrOfExecutionsToJoin+" joined");
execution.takeAll(outgoingTransitions, joinedExecutions);
} else if (log.isLoggable(Level.FINE)){
log.fine("parallel gateway '"+activity.getId()+"' does not activate: "+nbrOfExecutionsJoined+" of "+nbrOfExecutionsToJoin+" joined");
}
}
}