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 org.apache.commons.lang3.StringUtils;
  23 import org.opendaylight.mdsal.binding.generator.util.JavassistUtils;
  24 import org.slf4j.Logger;
  25 import org.slf4j.LoggerFactory;
  26 import javassist.ClassPool;
  27
  28 public class SingletonHolder {
  29     private static final Logger logger = 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     /**
  46      * @deprecated This method is only used from configuration modules and thus callers of it
  47      *             should use service injection to make the executor configurable.
  48      */
  49     @Deprecated
  50     public static synchronized ListeningExecutorService getDefaultNotificationExecutor() {
  51
  52         if (NOTIFICATION_EXECUTOR == null) {
  53             int queueSize = MAX_NOTIFICATION_QUEUE_SIZE;
  54             final String queueValue = System.getProperty(NOTIFICATION_QUEUE_SIZE_PROPERTY);
  55             if (StringUtils.isNotBlank(queueValue)) {
  56                 try {
  57                     queueSize = Integer.parseInt(queueValue);
  58                     logger.trace("Queue size was set to {}", queueSize);
  59                 } catch (final NumberFormatException e) {
  60                     logger.warn("Cannot parse {} as set by {}, using default {}", queueValue,
  61                             NOTIFICATION_QUEUE_SIZE_PROPERTY, queueSize);
  62                 }
  63             }
  64
  65             // Overriding the queue:
  66             // ThreadPoolExecutor would not create new threads if the queue is not full, thus adding
  67             // occurs in RejectedExecutionHandler.
  68             // This impl saturates threadpool first, then queue. When both are full caller will get blocked.
  69             final BlockingQueue<Runnable> delegate = new LinkedBlockingQueue<>(queueSize);
  70             final BlockingQueue<Runnable> queue = new ForwardingBlockingQueue<Runnable>() {
  71                 @Override
  72                 protected BlockingQueue<Runnable> delegate() {
  73                     return delegate;
  74                 }
  75
  76                 @Override
  77                 public boolean offer(final Runnable r) {
  78                     // ThreadPoolExecutor will spawn a new thread after core size is reached only
  79                     // if the queue.offer returns false.
  80                     return false;
  81                 }
  82             };
  83
  84             final ThreadFactory factory = new ThreadFactoryBuilder()
  85             .setDaemon(true)
  86             .setNameFormat("md-sal-binding-notification-%d")
  87             .build();
  88
  89             final ThreadPoolExecutor executor = new ThreadPoolExecutor(CORE_NOTIFICATION_THREADS, MAX_NOTIFICATION_THREADS,
  90                     NOTIFICATION_THREAD_LIFE, TimeUnit.SECONDS, queue, factory,
  91                     // if the max threads are met, then it will raise a rejectedExecution. We then push to the queue.
  92                     (r, executor1) -> {
  93                         try {
  94                             executor1.getQueue().put(r);
  95                         } catch (final InterruptedException e) {
  96                             throw new RejectedExecutionException("Interrupted while waiting on the queue", e);
  97                         }
  98                     });
  99
 100             NOTIFICATION_EXECUTOR = MoreExecutors.listeningDecorator(executor);
 101         }
 102
 103         return NOTIFICATION_EXECUTOR;
 104     }
 105
 106     /**
 107      * @deprecated This method is only used from configuration modules and thus callers of it
 108      *             should use service injection to make the executor configurable.
 109      */
 110     @Deprecated
 111     public static synchronized ListeningExecutorService getDefaultCommitExecutor() {
 112         if (COMMIT_EXECUTOR == null) {
 113             final ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true).setNameFormat("md-sal-binding-commit-%d").build();
 114             /*
 115              * FIXME: this used to be newCacheThreadPool(), but MD-SAL does not have transaction
 116              *        ordering guarantees, which means that using a concurrent threadpool results
 117              *        in application data being committed in random order, potentially resulting
 118              *        in inconsistent data being present. Once proper primitives are introduced,
 119              *        concurrency can be reintroduced.
 120              */
 121             final ExecutorService executor = Executors.newSingleThreadExecutor(factory);
 122             COMMIT_EXECUTOR = MoreExecutors.listeningDecorator(executor);
 123         }
 124
 125         return COMMIT_EXECUTOR;
 126     }
 127
 128     public static ExecutorService getDefaultChangeEventExecutor() {
 129         if (CHANGE_EVENT_EXECUTOR == null) {
 130             final ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true).setNameFormat("md-sal-binding-change-%d").build();
 131             /*
 132              * FIXME: this used to be newCacheThreadPool(), but MD-SAL does not have transaction
 133              *        ordering guarantees, which means that using a concurrent threadpool results
 134              *        in application data being committed in random order, potentially resulting
 135              *        in inconsistent data being present. Once proper primitives are introduced,
 136              *        concurrency can be reintroduced.
 137              */
 138             final ExecutorService executor = Executors.newSingleThreadExecutor(factory);
 139             CHANGE_EVENT_EXECUTOR  = MoreExecutors.listeningDecorator(executor);
 140         }
 141
 142         return CHANGE_EVENT_EXECUTOR;
 143     }
 144 }