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.ThreadFactory;
  20 import java.util.concurrent.ThreadPoolExecutor;
  21 import java.util.concurrent.TimeUnit;
  22 import javassist.ClassPool;
  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
  28 public final class SingletonHolder {
  29     private static final Logger LOG = LoggerFactory.getLogger(SingletonHolder.class);
  30
  31     public static final ClassPool CLASS_POOL = ClassPool.getDefault();
  32     public static final JavassistUtils JAVASSIST = JavassistUtils.forClassPool(CLASS_POOL);
  33
  34     public static final int CORE_NOTIFICATION_THREADS = 4;
  35     public static final int MAX_NOTIFICATION_THREADS = 32;
  36     // block caller thread after MAX_NOTIFICATION_THREADS + MAX_NOTIFICATION_QUEUE_SIZE pending notifications
  37     public static final int MAX_NOTIFICATION_QUEUE_SIZE = 1000;
  38     public static final int NOTIFICATION_THREAD_LIFE = 15;
  39     private static final String NOTIFICATION_QUEUE_SIZE_PROPERTY = "mdsal.notificationqueue.size";
  40
  41     private static ListeningExecutorService NOTIFICATION_EXECUTOR = null;
  42     private static ListeningExecutorService COMMIT_EXECUTOR = null;
  43     private static ListeningExecutorService CHANGE_EVENT_EXECUTOR = null;
  44
  45     private SingletonHolder() {
  46     }
  47
  48     /**
  49      * Deprecated.
  50      *
  51      * @deprecated This method is only used from configuration modules and thus callers of it
  52      *             should use service injection to make the executor configurable.
  53      */
  54     @Deprecated
  55     public static synchronized ListeningExecutorService getDefaultNotificationExecutor() {
  56
  57         if (NOTIFICATION_EXECUTOR == null) {
  58             int queueSize = MAX_NOTIFICATION_QUEUE_SIZE;
  59             final String queueValue = System.getProperty(NOTIFICATION_QUEUE_SIZE_PROPERTY);
  60             if (StringUtils.isNotBlank(queueValue)) {
  61                 try {
  62                     queueSize = Integer.parseInt(queueValue);
  63                     LOG.trace("Queue size was set to {}", queueSize);
  64                 } catch (final NumberFormatException e) {
  65                     LOG.warn("Cannot parse {} as set by {}, using default {}", queueValue,
  66                             NOTIFICATION_QUEUE_SIZE_PROPERTY, queueSize);
  67                 }
  68             }
  69
  70             // Overriding the queue:
  71             // ThreadPoolExecutor would not create new threads if the queue is not full, thus adding
  72             // occurs in RejectedExecutionHandler.
  73             // This impl saturates threadpool first, then queue. When both are full caller will get blocked.
  74             final BlockingQueue<Runnable> delegate = new LinkedBlockingQueue<>(queueSize);
  75             final BlockingQueue<Runnable> queue = new ForwardingBlockingQueue<Runnable>() {
  76                 @Override
  77                 protected BlockingQueue<Runnable> delegate() {
  78                     return delegate;
  79                 }
  80
  81                 @Override
  82                 public boolean offer(final Runnable runnrunnableable) {
  83                     // ThreadPoolExecutor will spawn a new thread after core size is reached only
  84                     // if the queue.offer returns false.
  85                     return false;
  86                 }
  87             };
  88
  89             final ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true)
  90                     .setNameFormat("md-sal-binding-notification-%d").build();
  91
  92             final ThreadPoolExecutor executor = new ThreadPoolExecutor(CORE_NOTIFICATION_THREADS,
  93                 MAX_NOTIFICATION_THREADS, NOTIFICATION_THREAD_LIFE, TimeUnit.SECONDS, queue, factory,
  94                 // if the max threads are met, then it will raise a rejectedExecution. We then push to the queue.
  95                 (runnable, executor1) -> {
  96                     try {
  97                         executor1.getQueue().put(runnable);
  98                     } catch (final InterruptedException e) {
  99                         throw new RejectedExecutionException("Interrupted while waiting on the queue", e);
 100                     }
 101                 });
 102
 103             NOTIFICATION_EXECUTOR = MoreExecutors.listeningDecorator(executor);
 104         }
 105
 106         return NOTIFICATION_EXECUTOR;
 107     }
 108
 109     /**
 110      * Deprecated.
 111      *
 112      * @deprecated This method is only used from configuration modules and thus callers of it
 113      *             should use service injection to make the executor configurable.
 114      */
 115     @Deprecated
 116     public static synchronized ListeningExecutorService getDefaultCommitExecutor() {
 117         if (COMMIT_EXECUTOR == null) {
 118             final ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true)
 119                     .setNameFormat("md-sal-binding-commit-%d").build();
 120             /*
 121              * FIXME: this used to be newCacheThreadPool(), but MD-SAL does not have transaction
 122              *        ordering guarantees, which means that using a concurrent threadpool results
 123              *        in application data being committed in random order, potentially resulting
 124              *        in inconsistent data being present. Once proper primitives are introduced,
 125              *        concurrency can be reintroduced.
 126              */
 127             final ExecutorService executor = Executors.newSingleThreadExecutor(factory);
 128             COMMIT_EXECUTOR = MoreExecutors.listeningDecorator(executor);
 129         }
 130
 131         return COMMIT_EXECUTOR;
 132     }
 133
 134     public static synchronized ExecutorService getDefaultChangeEventExecutor() {
 135         if (CHANGE_EVENT_EXECUTOR == null) {
 136             final ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true)
 137                     .setNameFormat("md-sal-binding-change-%d").build();
 138             /*
 139              * FIXME: this used to be newCacheThreadPool(), but MD-SAL does not have transaction
 140              *        ordering guarantees, which means that using a concurrent threadpool results
 141              *        in application data being committed in random order, potentially resulting
 142              *        in inconsistent data being present. Once proper primitives are introduced,
 143              *        concurrency can be reintroduced.
 144              */
 145             final ExecutorService executor = Executors.newSingleThreadExecutor(factory);
 146             CHANGE_EVENT_EXECUTOR  = MoreExecutors.listeningDecorator(executor);
 147         }
 148
 149         return CHANGE_EVENT_EXECUTOR;
 150     }
 151 }