| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.felix.dm.impl; |
| |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.Executor; |
| |
| import org.apache.felix.dm.Component; |
| import org.apache.felix.dm.ComponentDeclaration; |
| import org.apache.felix.dm.ComponentExecutorFactory; |
| import org.apache.felix.dm.context.ComponentContext; |
| import org.osgi.framework.BundleContext; |
| |
| /** |
| * The Dependency Manager delegates all components addition/removal to this class. |
| * If a ComponentExecutorFactory is registered in the OSGi registry, this class will use it to get an |
| * Executor used for components management and lifecycle callbacks. |
| * |
| * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a> |
| */ |
| public class ComponentScheduler { |
| private final static ComponentScheduler m_instance = new ComponentScheduler(); |
| private final static String PARALLEL = "org.apache.felix.dependencymanager.parallel"; |
| private volatile ComponentExecutorFactory m_componentExecutorFactory; |
| private final Executor m_serial = new SerialExecutor(null); |
| private ConcurrentMap<Component, Component> m_pending = new ConcurrentHashMap<>(); |
| |
| public static ComponentScheduler instance() { |
| return m_instance; |
| } |
| |
| protected void bind(final ComponentExecutorFactory componentExecutorFactory) { |
| m_componentExecutorFactory = componentExecutorFactory; |
| m_serial.execute(new Runnable() { |
| @Override |
| public void run() { |
| for (Component c : m_pending.keySet()) { |
| createComponentExecutor(m_componentExecutorFactory, c); |
| ((ComponentContext) c).start(); |
| } |
| m_pending.clear(); |
| } |
| }); |
| } |
| |
| protected void unbind(ComponentExecutorFactory threadPool) { |
| m_componentExecutorFactory = null; |
| } |
| |
| public void add(final Component c) { |
| if (mayStartNow(c)) { |
| ((ComponentContext) c).start(); |
| } |
| else { |
| // The component requires a threadpool: delay execution until one is available. |
| m_serial.execute(new Runnable() { |
| @Override |
| public void run() { |
| ComponentExecutorFactory execFactory = m_componentExecutorFactory; |
| if (execFactory == null) { |
| m_pending.put(c, c); |
| } |
| else { |
| createComponentExecutor(execFactory, c); |
| ((ComponentContext) c).start(); |
| } |
| } |
| }); |
| } |
| } |
| |
| public void remove(final Component c) { |
| m_pending.remove(c); |
| ((ComponentContext) c).stop(); |
| } |
| |
| private boolean mayStartNow(Component c) { |
| ComponentExecutorFactory execFactory = m_componentExecutorFactory; |
| BundleContext ctx = c.getDependencyManager().getBundleContext(); |
| String parallel = ctx.getProperty(PARALLEL); |
| |
| if (execFactory == null) { |
| // No ComponentExecutorFactory available. If a "parallel" OSGi system property is specified, |
| // we have to wait for a ComponentExecutorFactory servoce if the component class name is matching one of the |
| // prefixes specified in the "parallel" system property. |
| if (parallel != null && requiresThreadPool(c, parallel)) { |
| return false; // wait for a threadpool |
| } else { |
| return true; // no threadpool required, start the component now, synchronously |
| } |
| } |
| else { |
| // A threadpool is there. If the "parallel" OSGi system property is not specified, we can start the component |
| // now and we'll use the threadpool for it. |
| // But if the "parallel" system property is specified, the component will use the threadpool only if it's |
| // classname is starting with one of the prefixes specified in the property. |
| if (parallel == null || requiresThreadPool(c, parallel)) { |
| createComponentExecutor(execFactory, c); |
| } |
| return true; // start the component now, possibly using the threadpool (see above). |
| } |
| } |
| |
| private boolean requiresThreadPool(Component c, String parallel) { |
| // The component declared from our DM Activator can not be parallel. |
| ComponentDeclaration decl = c.getComponentDeclaration(); |
| if (ComponentScheduler.class.getName().equals(decl.getName())) { |
| return false; |
| } |
| |
| for (String prefix : parallel.trim().split(",")) { |
| prefix = prefix.trim(); |
| boolean not = prefix.startsWith("!"); |
| if (not) { |
| prefix = prefix.substring(1).trim(); |
| } |
| if ("*".equals(prefix) || c.getComponentDeclaration().getClassName().startsWith(prefix)) { |
| return !not; |
| } |
| } |
| return false; |
| } |
| |
| private void createComponentExecutor(ComponentExecutorFactory execFactory, Component c) { |
| Executor exec = execFactory.getExecutorFor(c); |
| if (exec != null) { |
| ((ComponentContext) c).setThreadPool(exec); |
| } |
| } |
| } |