IncrementalBuilderExecutorManager.java

/*
 * Copyright 2015 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.
 * 
 *      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.guvnor.common.services.builder;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import javax.ejb.Asynchronous;
import javax.ejb.Singleton;
import javax.ejb.Startup;
import javax.ejb.TransactionAttribute;
import javax.enterprise.event.Event;
import javax.inject.Inject;

import org.guvnor.common.services.project.builder.model.BuildResults;
import org.guvnor.common.services.project.builder.model.IncrementalBuildResults;
import org.guvnor.common.services.project.builder.service.BuildService;
import org.guvnor.common.services.project.model.Project;
import org.guvnor.common.services.project.service.ProjectService;
import org.uberfire.commons.async.DescriptiveRunnable;
import org.uberfire.commons.async.DescriptiveThreadFactory;

import static javax.ejb.TransactionAttributeType.*;

@Singleton
@Startup
@TransactionAttribute(NOT_SUPPORTED)
public class IncrementalBuilderExecutorManager {

    @Inject
    private ProjectService<? extends Project> projectService;

    @Inject
    private BuildService buildService;

    @Inject
    private Event<BuildResults> buildResultsEvent;

    @Inject
    private Event<IncrementalBuildResults> incrementalBuildResultsEvent;

    private AtomicBoolean useExecService = new AtomicBoolean( false );
    private ExecutorService executorService = null;

    @Asynchronous
    public void execute( final AsyncIncrementalBuilder incrementalBuilder ) {
        if ( useExecService.get() ) {
            getExecutorService().execute( new DescriptiveRunnable() {
                @Override
                public void run() {
                    incrementalBuilder.execute( projectService,
                                                buildService,
                                                incrementalBuildResultsEvent,
                                                buildResultsEvent );
                }

                @Override
                public String getDescription() {
                    return incrementalBuilder.getDescription();
                }
            } );
        } else {
            incrementalBuilder.execute( projectService,
                                        buildService,
                                        incrementalBuildResultsEvent,
                                        buildResultsEvent );
        }
    }

    //Public so we can set the ExecutorService for tests not within guvnor
    public void setExecutorService( final ExecutorService executorService ) {
        this.executorService = executorService;
        this.useExecService.set( true );
    }

    private ExecutorService getExecutorService() {
        if ( executorService == null ) {
            executorService = Executors.newCachedThreadPool( new DescriptiveThreadFactory() );
        }
        return executorService;
    }

    public void setServices( final ProjectService projectService,
                             final BuildService buildService,
                             final Event<BuildResults> buildResultsEvent,
                             final Event<IncrementalBuildResults> incrementalBuildResultsEvent ) {
        this.projectService = projectService;
        this.buildService = buildService;
        this.buildResultsEvent = buildResultsEvent;
        this.incrementalBuildResultsEvent = incrementalBuildResultsEvent;
        this.useExecService.set( true );
    }

    public void shutdown() {
        if ( useExecService.get() && executorService != null ) {
            executorService.shutdown(); // Disable new tasks from being submitted
            try {
                // Wait a while for existing tasks to terminate
                if ( !executorService.awaitTermination( 60, TimeUnit.SECONDS ) ) {
                    executorService.shutdownNow(); // Cancel currently executing tasks
                    // Wait a while for tasks to respond to being cancelled
                    if ( !executorService.awaitTermination( 60, TimeUnit.SECONDS ) ) {
                        System.err.println( "Pool did not terminate" );
                    }
                }
            } catch ( InterruptedException ie ) {
                // (Re-)Cancel if current thread also interrupted
                executorService.shutdownNow();
                // Preserve interrupt status
                Thread.currentThread().interrupt();
            }
        }
    }
}