Place an upper bound on notification concurrency

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

diff --git a/opendaylight/md-sal/sal-binding-broker/src/main/java/org/opendaylight/controller/sal/binding/codegen/impl/SingletonHolder.java b/opendaylight/md-sal/sal-binding-broker/src/main/java/org/opendaylight/controller/sal/binding/codegen/impl/SingletonHolder.java
index 446a9caf8e7fd48f415926f457c6e68abcf73745..790c1fcd4c61cb95f7f624392ab9fcc60b7d2089 100644 (file)
--- a/opendaylight/md-sal/sal-binding-broker/src/main/java/org/opendaylight/controller/sal/binding/codegen/impl/SingletonHolder.java
+++ b/opendaylight/md-sal/sal-binding-broker/src/main/java/org/opendaylight/controller/sal/binding/codegen/impl/SingletonHolder.java
@@ -1,9 +1,20 @@
+/*
+ * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
 package org.opendaylight.controller.sal.binding.codegen.impl;
 
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+import javassist.ClassPool;
 
 import org.opendaylight.controller.sal.binding.codegen.RuntimeCodeGenerator;
 import org.opendaylight.controller.sal.binding.spi.NotificationInvokerFactory;
@@ -12,8 +23,6 @@ import com.google.common.util.concurrent.ListeningExecutorService;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 
-import javassist.ClassPool;
-
 public class SingletonHolder {
 
     public static final ClassPool CLASS_POOL = new ClassPool();
@@ -21,29 +30,66 @@ public class SingletonHolder {
             CLASS_POOL);
     public static final RuntimeCodeGenerator RPC_GENERATOR = RPC_GENERATOR_IMPL;
     public static final NotificationInvokerFactory INVOKER_FACTORY = RPC_GENERATOR_IMPL.getInvokerFactory();
+
+    public static final int CORE_NOTIFICATION_THREADS = 4;
+    public static final int MAX_NOTIFICATION_THREADS = 32;
+    public static final int NOTIFICATION_THREAD_LIFE = 15;
+
     private static ListeningExecutorService NOTIFICATION_EXECUTOR = null;
     private static ListeningExecutorService COMMIT_EXECUTOR = null;
+    private static ListeningExecutorService CHANGE_EVENT_EXECUTOR = null;
 
+    /**
+     * @deprecated This method is only used from configuration modules and thus callers of it
+     *             should use service injection to make the executor configurable.
+     */
+    @Deprecated
     public static synchronized final ListeningExecutorService getDefaultNotificationExecutor() {
         if (NOTIFICATION_EXECUTOR == null) {
-            NOTIFICATION_EXECUTOR = createNamedExecutor("md-sal-binding-notification-%d");
+            ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true).setNameFormat("md-sal-binding-notification-%d").build();
+            ExecutorService executor = new ThreadPoolExecutor(CORE_NOTIFICATION_THREADS, MAX_NOTIFICATION_THREADS,
+                    NOTIFICATION_THREAD_LIFE, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(), factory);
+            NOTIFICATION_EXECUTOR = MoreExecutors.listeningDecorator(executor);
         }
         return NOTIFICATION_EXECUTOR;
     }
 
+    /**
+     * @deprecated This method is only used from configuration modules and thus callers of it
+     *             should use service injection to make the executor configurable.
+     */
+    @Deprecated
     public static synchronized final ListeningExecutorService getDefaultCommitExecutor() {
         if (COMMIT_EXECUTOR == null) {
-            COMMIT_EXECUTOR = createNamedExecutor("md-sal-binding-commit-%d");
+            ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true).setNameFormat("md-sal-binding-commit-%d").build();
+            /*
+             * FIXME: this used to be newCacheThreadPool(), but MD-SAL does not have transaction
+             *        ordering guarantees, which means that using a concurrent threadpool results
+             *        in application data being committed in random order, potentially resulting
+             *        in inconsistent data being present. Once proper primitives are introduced,
+             *        concurrency can be reintroduced.
+             */
+            ExecutorService executor = Executors.newSingleThreadExecutor(factory);
+            COMMIT_EXECUTOR = MoreExecutors.listeningDecorator(executor);
         }
 
         return COMMIT_EXECUTOR;
     }
 
-    private static ListeningExecutorService createNamedExecutor(String format) {
-        ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true).setNameFormat(format).build();
-        ExecutorService executor = Executors.newCachedThreadPool(factory);
-        return MoreExecutors.listeningDecorator(executor);
+    public static ExecutorService getDefaultChangeEventExecutor() {
+        if (CHANGE_EVENT_EXECUTOR == null) {
+            ThreadFactory factory = new ThreadFactoryBuilder().setDaemon(true).setNameFormat("md-sal-binding-change-%d").build();
+            /*
+             * FIXME: this used to be newCacheThreadPool(), but MD-SAL does not have transaction
+             *        ordering guarantees, which means that using a concurrent threadpool results
+             *        in application data being committed in random order, potentially resulting
+             *        in inconsistent data being present. Once proper primitives are introduced,
+             *        concurrency can be reintroduced.
+             */
+            ExecutorService executor = Executors.newSingleThreadExecutor(factory);
+            CHANGE_EVENT_EXECUTOR  = MoreExecutors.listeningDecorator(executor);
+        }
 
+        return CHANGE_EVENT_EXECUTOR;
     }
-
 }