opendaylight/md-sal/sal-binding-broker/src/main/java/org/opendaylight/controller/sal/binding/codegen/impl/SingletonHolder.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.sal.binding.codegen.impl;
   9
  10 import com.google.common.util.concurrent.ForwardingBlockingQueue;
  11 import com.google.common.util.concurrent.ListeningExecutorService;
  12 import com.google.common.util.concurrent.MoreExecutors;
  13 import com.google.common.util.concurrent.ThreadFactoryBuilder;
  14 import java.util.concurrent.BlockingQueue;
  15 import java.util.concurrent.ExecutorService;
  16 import java.util.concurrent.Executors;
  17 import java.util.concurrent.LinkedBlockingQueue;
  18 import java.util.concurrent.RejectedExecutionException;
  19 import java.util.concurrent.RejectedExecutionHandler;
  20 import java.util.concurrent.ThreadFactory;
  21 import java.util.concurrent.ThreadPoolExecutor;
  22 import java.util.concurrent.TimeUnit;
  23 import org.apache.commons.lang3.StringUtils;
  24 import org.opendaylight.mdsal.binding.generator.util.JavassistUtils;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27 import javassist.ClassPool;
  28
  29 public class SingletonHolder {
  30     private static final Logger logger = LoggerFactory.getLogger(SingletonHolder.class);
  31
  32     public static final ClassPool CLASS_POOL = ClassPool.getDefault();
  33     public static final JavassistUtils JAVASSIST = JavassistUtils.forClassPool(CLASS_POOL);
  34
  35     public static final int CORE_NOTIFICATION_THREADS = 4;
  36     public static final int MAX_NOTIFICATION_THREADS = 32;
  37     // block caller thread after MAX_NOTIFICATION_THREADS + MAX_NOTIFICATION_QUEUE_SIZE pending notifications
  38     public static final int MAX_NOTIFICATION_QUEUE_SIZE = 1000;
  39     public static final int NOTIFICATION_THREAD_LIFE = 15;
  40     private static final String NOTIFICATION_QUEUE_SIZE_PROPERTY = "mdsal.notificationqueue.size";
  41
  42     private static ListeningExecutorService NOTIFICATION_EXECUTOR = null;
  43     private static ListeningExecutorService COMMIT_EXECUTOR = null;
  44     private static ListeningExecutorService CHANGE_EVENT_EXECUTOR = null;
  45
  46     /**
  47      * @deprecated This method is only used from configuration modules and thus callers of it
  48      *             should use service injection to make the executor configurable.
  49      */
  50     @Deprecated
  51     public static synchronized ListeningExecutorService getDefaultNotificationExecutor() {
  52
  53         if (NOTIFICATION_EXECUTOR == null) {
  54             int queueSize = MAX_NOTIFICATION_QUEUE_SIZE;
  55             final String queueValue = System.getProperty(NOTIFICATION_QUEUE_SIZE_PROPERTY);
  56             if (StringUtils.isNotBlank(queueValue)) {
  57                 try {
  58                     queueSize = Integer.parseInt(queueValue);
  59                     logger.trace("Queue size was set to {}", queueSize);
  60                 } catch (final NumberFormatException e) {
  61                     logger.warn("Cannot parse {} as set by {}, using default {}", queueValue,
  62                             NOTIFICATION_QUEUE_SIZE_PROPERTY, queueSize);
  63                 }
  64             }
  65
  66             // Overriding the queue:
  67             // ThreadPoolExecutor would not create new threads if the queue is not full, thus adding
  68             // occurs in RejectedExecutionHandler.
  69             // This impl saturates threadpool first, then queue. When both are full caller will get blocked.
  70             final BlockingQueue<Runnable> delegate = new LinkedBlockingQueue<>(queueSize);
  71             final BlockingQueue<Runnable> queue = new ForwardingBlockingQueue<Runnable>() {
  72                 @Override
  73                 protected BlockingQueue<Runnable> delegate() {
  74                     return delegate;
  75                 }
  76
  77                 @Override
  78                 public boolean offer(final Runnable r) {
  79                     // ThreadPoolExecutor will spawn a new thread after core size is reached only
  80                     // if the queue.offer returns false.
  81                     return false;
  82                 }
  83             };
  84
  85             final ThreadFactory factory = new ThreadFactoryBuilder()
  86             .setDaemon(true)
  87             .setNameFormat("md-sal-binding-notification-%d")
  88             .build();
  89
  90             final ThreadPoolExecutor executor = new ThreadPoolExecutor(CORE_NOTIFICATION_THREADS, MAX_NOTIFICATION_THREADS,
  91                     NOTIFICATION_THREAD_LIFE, TimeUnit.SECONDS, queue, factory,
  92                     new RejectedExecutionHandler() {
  93                 // if the max threads are met, then it will raise a rejectedExecution. We then push to the queue.
  94                 @Override
  95                 public void rejectedExecution(final Runnable r, final ThreadPoolExecutor executor) {
  96                     try {
  97                         executor.getQueue().put(r);
  98                     } catch (final InterruptedException e) {
  99                         throw new RejectedExecutionException("Interrupted while waiting on the queue", e);
 100                     }
 101                 }
 102             });
 103
 104             NOTIFICATION_EXECUTOR = MoreExecutors.listeningDecorator(executor);
 105         }
 106
 107         return NOTIFICATION_EXECUTOR;
 108     }
 109
 110     /**
 111      * @deprecated This method is only used from configuration modules and thus callers of it
 112      *             should use service injection to make the executor configurable.
 113      */
 114     @Deprecated
 115     public static synchronized ListeningExecutorService getDefaultCommitExecutor() {
 116         if (COMMIT_EXECUTOR == null) {
 117             final ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true).setNameFormat("md-sal-binding-commit-%d").build();
 118             /*
 119              * FIXME: this used to be newCacheThreadPool(), but MD-SAL does not have transaction
 120              *        ordering guarantees, which means that using a concurrent threadpool results
 121              *        in application data being committed in random order, potentially resulting
 122              *        in inconsistent data being present. Once proper primitives are introduced,
 123              *        concurrency can be reintroduced.
 124              */
 125             final ExecutorService executor = Executors.newSingleThreadExecutor(factory);
 126             COMMIT_EXECUTOR = MoreExecutors.listeningDecorator(executor);
 127         }
 128
 129         return COMMIT_EXECUTOR;
 130     }
 131
 132     public static ExecutorService getDefaultChangeEventExecutor() {
 133         if (CHANGE_EVENT_EXECUTOR == null) {
 134             final ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true).setNameFormat("md-sal-binding-change-%d").build();
 135             /*
 136              * FIXME: this used to be newCacheThreadPool(), but MD-SAL does not have transaction
 137              *        ordering guarantees, which means that using a concurrent threadpool results
 138              *        in application data being committed in random order, potentially resulting
 139              *        in inconsistent data being present. Once proper primitives are introduced,
 140              *        concurrency can be reintroduced.
 141              */
 142             final ExecutorService executor = Executors.newSingleThreadExecutor(factory);
 143             CHANGE_EVENT_EXECUTOR  = MoreExecutors.listeningDecorator(executor);
 144         }
 145
 146         return CHANGE_EVENT_EXECUTOR;
 147     }
 148 }