# SynapseTaskManager.java

    /*
     *  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.synapse.task;

    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.synapse.commons.SynapseCommonsException;

    /**
     * Helper class to a share Scheduler and  TaskDescriptionRepository within a single class space
     */
    public class SynapseTaskManager {

        private static final Log log = LogFactory.getLog(SynapseTaskManager.class);

        private TaskDescriptionRepository taskDescriptionRepository;
        private TaskScheduler taskScheduler;
        private TaskManager taskManagerImpl;
        private boolean initialized = false;

        public SynapseTaskManager() {
            if (log.isDebugEnabled()) {
                log.debug("Created the SynapseTaskManager singleton instance");
            }
        }

        /**
         * Initialize the task manager instance with the given task description repository
         * and the task scheduler. If any of these arguments are null new instances will
         * be created. Note that this method does not initialize the actual task scheduler
         * instance. It is up to the task manager clients to make sure that is initialized.
         *
         * @param taskDescriptionRepository TaskDescriptionRepository  instance
         * @param taskScheduler             TaskScheduler instance
         */
        public void init(TaskDescriptionRepository taskDescriptionRepository,
                         TaskScheduler taskScheduler, TaskManager taskManagerImpl) {

            if (initialized) {
                if (log.isDebugEnabled()) {
                    log.debug("Task manager already initialized. Skipping re-initialization.");
                }
                return;
            }

            if(taskManagerImpl != null) {
                this.taskManagerImpl = taskManagerImpl;
            }

            if (taskDescriptionRepository != null) {
                this.taskDescriptionRepository = taskDescriptionRepository;
            } else {
                if (log.isDebugEnabled()) {
                    log.debug("Creating new TaskDescriptionRepository as given instance is null.");
                }
                this.taskDescriptionRepository =
                        TaskDescriptionRepositoryFactory.getTaskDescriptionRepository(
                                TaskConstants.TASK_DESCRIPTION_REPOSITORY);
            }

            if (taskScheduler != null) {
                this.taskScheduler = taskScheduler;
            } else {
                if (log.isDebugEnabled()) {
                    log.debug("Creating new TaskScheduler as given instance is null.");
                }
                this.taskScheduler = TaskSchedulerFactory.getTaskScheduler(TaskConstants.TASK_SCHEDULER);

            }
            initialized = true;
        }

        public TaskManager getTaskManagerImpl() {
            return taskManagerImpl;
        }

        public TaskDescriptionRepository getTaskDescriptionRepository() {
            assertInitialized();
            return taskDescriptionRepository;
        }

        public TaskScheduler getTaskScheduler() {
            assertInitialized();
            return taskScheduler;
        }

        private void assertInitialized() {
            if (!initialized) {
                String msg = "Task helper has not been initialized, it requires to be initialized";
                log.error(msg);
                throw new SynapseCommonsException(msg);
            }
        }

        public boolean isInitialized() {
            return initialized;
        }

        public void cleanup() {
            assertInitialized();
            log.info("Shutting down the task manager");
            /*taskDescriptionRepository.clear();*/
            taskScheduler.shutDown();
            initialized = false;
        }

        public void pauseAll() {
            if (taskScheduler != null) {
                if(taskScheduler.isInitialized()) {
                    try {
                        taskScheduler.pauseAll();
                    } catch (SynapseTaskException ignore) {
                        // This exceptions has already been logged and we don't want to interrupt the flow
                    }
                }
            }
        }

        public void resumeAll() {
            if (taskScheduler != null) {
                try {
                    taskScheduler.resumeAll();
                } catch (SynapseTaskException ignore) {
                    // This exceptions has already been logged and we don't want to interrupt the flow
                }
            }
        }
    }