/*
* Copyright 2016 Red Hat, Inc. and/or its affiliates.
*
* 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.drools.core.concurrent;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.Future;
import java.util.concurrent.LinkedBlockingQueue;
import org.drools.core.common.DefaultAgenda;
import org.drools.core.common.InternalAgendaGroup;
import org.drools.core.common.RuleBasePartitionId;
import org.drools.core.phreak.RuleAgendaItem;
import org.drools.core.spi.Activation;
import org.drools.core.spi.KnowledgeHelper;
import org.kie.api.runtime.rule.AgendaFilter;
import org.kie.internal.concurrent.ExecutorProviderFactory;
public class ParallelRuleEvaluator extends AbstractRuleEvaluator implements RuleEvaluator {
private static final RuleAgendaItem POISON_PILL = new RuleAgendaItem();
private final int evaluatorsNr = RuleBasePartitionId.PARALLEL_PARTITIONS_NUMBER;
private RuleEvaluatorCallable[] evaluators = new RuleEvaluatorCallable[evaluatorsNr];
private Future<Integer>[] results = new Future[evaluatorsNr];
private AgendaFilter filter;
private int fireCount;
private int fireLimit;
public ParallelRuleEvaluator( DefaultAgenda agenda ) {
super(agenda);
for (int i = 0; i < evaluatorsNr; i++) {
evaluators[i] = new RuleEvaluatorCallable();
}
}
private static class Completion {
private static final CompletionService<Integer> service = ExecutorProviderFactory.getExecutorProvider().getCompletionService();
}
@Override
public int evaluateAndFire( AgendaFilter filter,
int fireCount,
int fireLimit,
InternalAgendaGroup group ) {
this.filter = filter;
this.fireCount = fireCount;
this.fireLimit = fireLimit;
Activation[] activations = group.getActivations();
for ( Activation activation : activations ) {
RuleAgendaItem item = (RuleAgendaItem) activation;
int index = item.getPartition().getParallelEvaluationSlot();
RuleEvaluatorCallable evaluator = evaluators[index];
evaluator.enqueue( item );
if ( !evaluator.running ) {
evaluator.running = true;
results[index] = Completion.service.submit( evaluator );
}
}
int localFireCount = 0;
for (int i = 0; i < evaluatorsNr; i++) {
if (results[i] != null) {
try {
evaluators[i].enqueue( POISON_PILL );
localFireCount += results[i].get();
} catch (Exception e) {
throw new RuntimeException( e );
} finally {
results[i] = null;
}
}
}
return localFireCount;
}
@Override
public KnowledgeHelper getKnowledgeHelper() {
throw new UnsupportedOperationException();
}
public class RuleEvaluatorCallable implements Callable<Integer> {
private final BlockingQueue<RuleAgendaItem> queue = new LinkedBlockingQueue<>();
private final KnowledgeHelper knowledgeHelper = newKnowledgeHelper();
private boolean running = false;
@Override
public Integer call() {
int count = 0;
while (true) {
try {
RuleAgendaItem item = queue.take();
if (item == POISON_PILL) {
break;
}
count += internalEvaluateAndFire( filter, fireCount, fireLimit, item );
} catch (InterruptedException e) {
throw new RuntimeException( e );
}
}
running = false;
return count;
}
private void enqueue(RuleAgendaItem item) {
queue.offer( item );
}
}
}