| /** |
| * |
| * Copyright 2005 the original author or authors. |
| * |
| * 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.gbean.kernel; |
| |
| /** |
| * This condition that requires another service be in the RUNNING state to be satisfied. |
| * |
| * @author Dain Sundstrom |
| * @version $Id$ |
| * @since 1.0 |
| */ |
| public class RunningServiceCondition implements ServiceCondition { |
| private final ServiceName dependency; |
| private final boolean ownedRelationship; |
| private final boolean stopOnServiceShutdown; |
| private final DependencyServiceMonitor serviceMonitor = new DependencyServiceMonitor(); |
| |
| private ServiceConditionContext context; |
| private boolean satisfied = true; |
| private StoppedServiceCondition stoppedServiceCondition; |
| |
| /** |
| * Creates a condition that requires the specified service be in the RUNNING state to be satisfied. |
| * |
| * @param dependency the service that must be running |
| * @param ownedRelationship if true the condition will register the relationship |
| * @param stopOnServiceShutdown if the our service should be stopped when the specified service shutsdown |
| */ |
| public RunningServiceCondition(ServiceName dependency, boolean ownedRelationship, boolean stopOnServiceShutdown) { |
| if (dependency == null) throw new NullPointerException("dependency is null"); |
| this.dependency = dependency; |
| this.ownedRelationship = ownedRelationship; |
| this.stopOnServiceShutdown = stopOnServiceShutdown; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public synchronized void initialize(ServiceConditionContext context) { |
| if (context == null) throw new NullPointerException("context is null"); |
| |
| // if we have no been destroyed, destroy not |
| if (this.context != null) { |
| destroy(); |
| } |
| |
| this.context = context; |
| |
| satisfied = false; |
| context.getKernel().addServiceMonitor(serviceMonitor, dependency); |
| if (ownedRelationship) { |
| // todo register owned relationship |
| } |
| |
| if (stopOnServiceShutdown) { |
| stoppedServiceCondition = new StoppedServiceCondition(context.getServiceName()); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public synchronized boolean isSatisfied() { |
| if (context == null) { |
| // we are not initialized so default to true |
| return true; |
| } |
| |
| if (!satisfied) { |
| try { |
| // grab a synchronized lock on the service factory to assure that the state doesn't change while |
| // adding the dependency.... the kernel will grab the same lock when getting the stop dependencies |
| ServiceFactory serviceFactory = context.getKernel().getServiceFactory(dependency); |
| synchronized (serviceFactory) { |
| if (context.getKernel().getService(dependency) == ServiceState.RUNNING) { |
| if (stopOnServiceShutdown) { |
| serviceFactory.addStopCondition(stoppedServiceCondition); |
| } |
| satisfied = true; |
| context.getKernel().removeServiceMonitor(serviceMonitor); |
| } |
| } |
| } catch (ServiceNotFoundException ignored) { |
| // service hasn't registered yet |
| } |
| } |
| return satisfied; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public synchronized void destroy() { |
| if (context == null) { |
| // we are already destroyed |
| return; |
| } |
| |
| context.getKernel().removeServiceMonitor(serviceMonitor); |
| context = null; |
| satisfied = true; |
| if (ownedRelationship) { |
| // todo unregister owned relationship |
| } |
| if (stopOnServiceShutdown) { |
| stoppedServiceCondition.destroy(); |
| stoppedServiceCondition = null; |
| } |
| } |
| |
| private class DependencyServiceMonitor extends NullServiceMonitor { |
| public void serviceRunning(ServiceEvent serviceEvent) { |
| synchronized (RunningServiceCondition.this) { |
| if (context != null) { |
| // we aren't running anymore |
| return; |
| } |
| |
| if (!satisfied) { |
| return; |
| } |
| |
| if (isSatisfied()) { |
| context.setSatisfied(); |
| } |
| } |
| } |
| } |
| } |