| /** |
| * |
| * 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.standard; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import edu.emory.mathcs.backport.java.util.concurrent.locks.Condition; |
| import edu.emory.mathcs.backport.java.util.concurrent.locks.Lock; |
| import org.gbean.kernel.Kernel; |
| import org.gbean.kernel.ServiceCondition; |
| import org.gbean.kernel.ServiceName; |
| |
| /** |
| * Aggregates a set of ServiceConditions together so the ServiceManager can treat them as a single unit. |
| * |
| * @author Dain Sundstrom |
| * @version $Id$ |
| * @since 1.0 |
| */ |
| public class AggregateCondition { |
| private final Kernel kernel; |
| private final ServiceName serviceName; |
| private final ClassLoader classLoader; |
| private final Lock lock; |
| private final Map conditions = new HashMap(); |
| private final Condition satisfiedSignal; |
| private boolean destroyed = false; |
| |
| /** |
| * Creates an aggregate condition. |
| * |
| * @param kernel the kernel in which the service is registered |
| * @param serviceName the name of the service |
| * @param classLoader the class loader for the service |
| * @param lock the lock for the service manager |
| * @param conditions the conditions |
| */ |
| public AggregateCondition(Kernel kernel, ServiceName serviceName, ClassLoader classLoader, Lock lock, Set conditions) { |
| this.kernel = kernel; |
| this.serviceName = serviceName; |
| this.classLoader = classLoader; |
| this.lock = lock; |
| satisfiedSignal = lock.newCondition(); |
| |
| // add the conditions to the registry |
| if (conditions == null) throw new NullPointerException("conditions is null"); |
| for (Iterator iterator = conditions.iterator(); iterator.hasNext();) { |
| ServiceCondition serviceCondition = (ServiceCondition) iterator.next(); |
| addCondition(serviceCondition); |
| } |
| } |
| |
| /** |
| * Gets a snapshot of the current conditions. |
| * |
| * @return a snapshot of the current conditions |
| */ |
| protected Set getConditions() { |
| return new HashSet(conditions.keySet()); |
| } |
| |
| /** |
| * Adds a new condition if not already registered. |
| * |
| * @param condition the new condition |
| */ |
| protected final void addCondition(ServiceCondition condition) { |
| if (!conditions.containsKey(condition)) { |
| StandardServiceConditionContext context = new StandardServiceConditionContext(kernel, serviceName, classLoader, lock, satisfiedSignal); |
| condition.initialize(context); |
| conditions.put(condition, context); |
| } |
| } |
| |
| /** |
| * Removes a condition from the registry if present. |
| * |
| * @param condition the condition to remove |
| */ |
| protected final void removeCondition(ServiceCondition condition) { |
| if (conditions.remove(condition) != null) { |
| condition.destroy(); |
| } |
| } |
| |
| /** |
| * Initializes the conditions. |
| */ |
| public void initialize() { |
| if (destroyed) throw new IllegalStateException("destroyed"); |
| |
| for (Iterator iterator = conditions.entrySet().iterator(); iterator.hasNext();) { |
| Map.Entry entry = (Map.Entry) iterator.next(); |
| ServiceCondition condition = (ServiceCondition) entry.getKey(); |
| StandardServiceConditionContext context = (StandardServiceConditionContext) entry.getValue(); |
| condition.initialize(context); |
| } |
| } |
| |
| /** |
| * Gets the unsatisfied conditions. |
| * |
| * @return the unstatisfied conditions |
| */ |
| public Set getUnsatisfied() { |
| if (destroyed) throw new IllegalStateException("destroyed"); |
| |
| Set unsatisfied = new HashSet(); |
| for (Iterator iterator = conditions.entrySet().iterator(); iterator.hasNext();) { |
| Map.Entry entry = (Map.Entry) iterator.next(); |
| ServiceCondition condition = (ServiceCondition) entry.getKey(); |
| StandardServiceConditionContext context = (StandardServiceConditionContext) entry.getValue(); |
| if (!context.isSatisfied()) { |
| if (condition.isSatisfied()) { |
| // the condition is satisfied |
| // record this fact in the context |
| context.setSatisfied(); |
| } else { |
| unsatisfied.add(condition); |
| } |
| } |
| } |
| |
| // notify anyone awaiting satisfaction |
| if (unsatisfied.isEmpty()) { |
| satisfiedSignal.signalAll(); |
| } |
| return unsatisfied; |
| } |
| |
| /** |
| * Gets the destroyed status. |
| * |
| * @return true if this AggregateCondition been destroyed; false otherwise |
| */ |
| public boolean isDestroyed() { |
| return destroyed; |
| } |
| |
| /** |
| * Destroys all condtions. |
| * |
| * @return a list of the Exceptions or Errors that occured while destroying the conditon objects. |
| */ |
| public List destroy() { |
| List stopErrors = new ArrayList(); |
| if (!destroyed) { |
| destroyed = true; |
| for (Iterator iterator = conditions.keySet().iterator(); iterator.hasNext();) { |
| ServiceCondition condition = (ServiceCondition) iterator.next(); |
| try { |
| condition.destroy(); |
| } catch (RuntimeException stopError) { |
| stopErrors.add(stopError); |
| } catch (Error stopError) { |
| stopErrors.add(stopError); |
| } |
| } |
| // notify anyone awaiting satisfaction |
| satisfiedSignal.signalAll(); |
| } |
| return stopErrors; |
| } |
| |
| /** |
| * Causes the current thread to wait until the conditons is satisfied. |
| * |
| * @throws InterruptedException if the thread is interrupted |
| */ |
| public void awaitSatisfaction() throws InterruptedException { |
| while (!destroyed) { |
| if (getUnsatisfied().isEmpty()) { |
| return; |
| } |
| satisfiedSignal.await(); |
| } |
| } |
| } |