    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
    015package org.apache.tapestry5.ioc;
    016
    017/**
    018 * Configuration symbols used by the IoC container.
    019 *
    020 * @since 5.2.2
    021 */
    022public 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}