| /* |
| * 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.ace.scheduler; |
| |
| import java.util.Collections; |
| import java.util.Dictionary; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| |
| import org.osgi.framework.Constants; |
| import org.osgi.service.cm.ConfigurationException; |
| import org.osgi.service.cm.ManagedService; |
| import org.osgi.service.log.LogService; |
| |
| /** |
| * The scheduler periodically runs tasks based on a scheduling recipe. Tasks can be added and removed using the |
| * <code>addRunnable</code> and <code>removeRunnable</code> methods. Recipes are supplied using configuration properties |
| * using the <code>updated</code> method, or are passed in the task's properties.<br> |
| * |
| * A task will be scheduled if both a <code>Runnable</code> and a <code>recipe</code> are available for it. |
| */ |
| public class Scheduler implements ManagedService { |
| protected final ConcurrentMap<String, SchedulerTask> m_tasks = new ConcurrentHashMap<>(); |
| private volatile LogService m_log; |
| |
| /** |
| * Makes sure that all tasks are indeed stopped when the scheduler is stopped. |
| */ |
| public void stop() { |
| for (SchedulerTask schedTask : m_tasks.values()) { |
| schedTask.stop(); |
| } |
| m_tasks.clear(); |
| } |
| |
| /** |
| * Adds a new runnable to this scheduler. The runnable will be created if necessary, registered, and processed. |
| * |
| * @param name |
| * A name for this task. |
| * @param task |
| * A runnable to run for this task. |
| * @param description |
| * A description of the task. |
| * @param recipe |
| * Optionally, a recipe for running this task. |
| * @param recipeOverride |
| * Indicates whether or not the <code>recipe</code> passed in prevails over any recipe provided by the |
| * <code>Scheduler</code>'s configuration. |
| * @throws ConfigurationException |
| * When <code>recipe</code> is not <code>null</code>, and cannot be decoded into a recipe. |
| */ |
| public void addRunnable(String name, Runnable task, String description, Object recipe, boolean recipeOverride) throws ConfigurationException { |
| SchedulerTask schedTask = m_tasks.get(name); |
| if (schedTask == null) { |
| schedTask = new SchedulerTask(name); |
| m_tasks.putIfAbsent(name, schedTask); |
| } |
| schedTask.updateTask(task, description, recipe, recipeOverride); |
| schedTask.process(); |
| } |
| |
| /** |
| * Removes a runnable from this scheduler. |
| * |
| * @param name |
| * The name of the runnable. If the name does not indicate a valid runnable, nothing is done. |
| */ |
| public void removeRunnable(String name) { |
| SchedulerTask schedTask = m_tasks.get(name); |
| if (schedTask != null) { |
| try { |
| schedTask.updateTask(null, null, null, false); |
| } |
| catch (ConfigurationException e) { |
| // Will not occur; a null recipe will not cause an exception. |
| } |
| if (!schedTask.process()) { |
| m_tasks.remove(name); |
| } |
| } |
| } |
| |
| /** |
| * Updates the configuration of the scheduler. The scheduler expects the configuration to contain recipes for |
| * scheduling. The key of a property should be the name identifying a task and the value should be a string |
| * describing the scheduling recipe for this task. |
| */ |
| public void updated(Dictionary<String, ?> properties) throws ConfigurationException { |
| if (properties == null) { |
| return; |
| } |
| |
| // first remove all the old schedules. |
| for (SchedulerTask schedTask : m_tasks.values()) { |
| schedTask.updateConfigurationRecipe(null); |
| } |
| |
| // then apply the new ones |
| properties.remove(Constants.SERVICE_PID); |
| |
| List<String> keys = Collections.list(properties.keys()); |
| for (String name : keys) { |
| SchedulerTask schedTask = m_tasks.get(name); |
| if (schedTask == null) { |
| schedTask = new SchedulerTask(name); |
| m_tasks.putIfAbsent(name, schedTask); |
| } |
| |
| try { |
| schedTask.updateConfigurationRecipe(properties.get(name)); |
| } |
| catch (ConfigurationException ce) { |
| // This is most likely an illegal recipe, caused by an config property we don't understand. |
| // So, no problem. |
| m_log.log(LogService.LOG_INFO, name + "=" + properties.get(name) + " does not look like a valid schedule recipe."); |
| } |
| } |
| |
| // and remove all tasks that now have no schedule or runnable |
| Iterator<String> i = m_tasks.keySet().iterator(); |
| while (i.hasNext()) { |
| SchedulerTask schedTask = m_tasks.get(i.next()); |
| if (!schedTask.process()) { |
| i.remove(); |
| } |
| } |
| } |
| } |