    001    // Copyright 2010, 2011 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    // http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.ioc;
    016
    017    /**
    018     * Configuration symbols used by the IoC container.
    019     *
    020     * @since 5.2.2
    021     */
    022    public class IOCSymbols
    023    {
    024        /**
    025         * The minimum size of the thread pool. The default is 3. When a task is created and there are fewer
    026         * than this number of threads in the pool, a new thread is created for the task.
    027         */
    028        public static final String THREAD_POOL_CORE_SIZE = "tapestry.thread-pool.core-pool-size";
    029
    030        /**
    031         * The size of the task queue. When there are at least {@linkplain #THREAD_POOL_CORE_SIZE the core number} of
    032         * threads in the pool, tasks will be placed in the queue. If the queue is empty, more threads
    033         * may be created (up to the {@linkplain #THREAD_POOL_MAX_SIZE maximum pool size}). If the queue is full and
    034         * all threads have been created, the task is rejected.
    035         * <p>
    036         * The default is 100.
    037         *
    038         * @since 5.3
    039         * @see <a href="http://www.bigsoft.co.uk/blog/index.php/2009/11/27/rules-of-a-threadpoolexecutor-pool-size">
    040         *     Rules of a ThreadPoolExecutor pool size
    041         *     </a>
    042         */
    043        public static final String THREAD_POOL_QUEUE_SIZE = "tapestry.thread-pool.queue-size";
    044
    045        /**
    046         * Maximium size of the thread pool, which defaults to 10.
    047         */
    048        public static final String THREAD_POOL_MAX_SIZE = "tapestry.thread-pool.max-pool-size";
    049
    050        /**
    051         * Time in milliseconds (via {@link org.apache.tapestry5.ioc.util.TimeInterval}) to keep waiting threads alive.
    052         * Default is one minute.
    053         */
    054        public static final String THREAD_POOL_KEEP_ALIVE = "tapestry.thread-pool.keep-alive";
    055
    056        /**
    057         * By default, the {@link org.apache.tapestry5.ioc.services.ParallelExecutor} service uses a thread pool. In
    058         * environments (such as Google Application Engine) where thread creation is not allowed, this can be set to
    059         * "false", and deferred logic will, instead, execute immediately.
    060         *
    061         * @since 5.1.0.3
    062         */
    063        public static final String THREAD_POOL_ENABLED = "tapestry.thread-pool-enabled";
    064    }