/*
* JBoss, Home of Professional Open Source
* Copyright 2012, Red Hat, Inc., and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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.jboss.weld.bootstrap.events;
import java.lang.reflect.Type;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.jboss.weld.event.ObserverNotifier;
import org.jboss.weld.executor.DaemonThreadFactory;
import org.jboss.weld.util.reflection.ParameterizedTypeImpl;
import edu.umd.cs.findbugs.annotations.SuppressWarnings;
/**
* Allows observer methods for container lifecycle events to be resolved upfront while the deployment is waiting for classloader
* or reflection API.
*
* @author Jozef Hartinger
*
*/
public class ContainerLifecycleEventPreloader {
private class PreloadingTask implements Callable<Void> {
private final Type type;
public PreloadingTask(Type type) {
this.type = type;
}
@Override
public Void call() throws Exception {
notifier.resolveObserverMethods(type);
return null;
}
}
private final ExecutorService executor;
private final ObserverNotifier notifier;
public ContainerLifecycleEventPreloader(int threadPoolSize, ObserverNotifier notifier) {
this.executor = Executors.newFixedThreadPool(threadPoolSize, new DaemonThreadFactory(new ThreadGroup("weld-preloaders"), "weld-preloader-"));
this.notifier = notifier;
}
/**
* In multi-threaded environment we often cannot leverage multiple core fully in bootstrap because the deployer
* threads are often blocked by the reflection API or waiting to get a classloader lock. While waiting for classes to be loaded or
* reflection metadata to be obtained, we can make use of the idle CPU cores and start resolving container lifecycle event observers
* (extensions) upfront for those types of events we know we will be firing. Since these resolutions are cached, firing of the
* lifecycle events will then be very fast.
*
*/
@SuppressWarnings(value = "RV_RETURN_VALUE_IGNORED_BAD_PRACTICE", justification = "We never need to synchronize with the preloader.")
void preloadContainerLifecycleEvent(Class<?> eventRawType, Type... typeParameters) {
executor.submit(new PreloadingTask(new ParameterizedTypeImpl(eventRawType, typeParameters, null)));
}
void shutdown() {
if (!executor.isShutdown()) {
executor.shutdownNow();
}
}
}