binding/mdsal-binding-api/src/main/java/org/opendaylight/controller/sal/binding/api/AbstractBrokerAwareActivator.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.api;
   9
  10 import java.util.concurrent.ExecutorService;
  11 import java.util.concurrent.Executors;
  12 import org.osgi.framework.BundleActivator;
  13 import org.osgi.framework.BundleContext;
  14 import org.osgi.framework.ServiceReference;
  15 import org.osgi.util.tracker.ServiceTracker;
  16 import org.osgi.util.tracker.ServiceTrackerCustomizer;
  17
  18 public abstract class AbstractBrokerAwareActivator implements BundleActivator {
  19
  20     private static final ExecutorService mdActivationPool = Executors.newCachedThreadPool();
  21     private BundleContext context;
  22     private ServiceTracker<BindingAwareBroker, BindingAwareBroker> tracker;
  23     private BindingAwareBroker broker;
  24     private final ServiceTrackerCustomizer<BindingAwareBroker, BindingAwareBroker> customizer = new ServiceTrackerCustomizer<BindingAwareBroker, BindingAwareBroker>() {
  25
  26         @Override
  27         public BindingAwareBroker addingService(final ServiceReference<BindingAwareBroker> reference) {
  28             broker = context.getService(reference);
  29             mdActivationPool.execute(new Runnable() {
  30
  31                 @Override
  32                 public void run() {
  33                     onBrokerAvailable(broker, context);
  34                 }
  35             });
  36             return broker;
  37         }
  38
  39         @Override
  40         public void modifiedService(final ServiceReference<BindingAwareBroker> reference, final BindingAwareBroker service) {
  41             removedService(reference, service);
  42             addingService(reference);
  43         }
  44
  45         @Override
  46         public void removedService(final ServiceReference<BindingAwareBroker> reference, final BindingAwareBroker service) {
  47             broker = context.getService(reference);
  48             mdActivationPool.execute(new Runnable() {
  49
  50                 @Override
  51                 public void run() {
  52                     onBrokerRemoved(broker, context);
  53                 }
  54             });
  55         }
  56
  57     };
  58
  59
  60     @Override
  61     public final void start(final BundleContext context) throws Exception {
  62         this.context = context;
  63         startImpl(context);
  64         tracker = new ServiceTracker<>(context, BindingAwareBroker.class, customizer);
  65         tracker.open();
  66
  67     }
  68
  69
  70
  71     @Override
  72     public final  void stop(final BundleContext context) throws Exception {
  73         tracker.close();
  74         stopImpl(context);
  75     }
  76
  77     protected void startImpl(final BundleContext context) throws Exception {
  78         // NOOP
  79     }
  80
  81     /**
  82      * Called when this bundle is stopped so the Framework can perform the
  83      * bundle-specific activities necessary to stop the bundle. In general, this
  84      * method should undo the work that the {@code BundleActivator.start} method
  85      * started. There should be no active threads that were started by this
  86      * bundle when this bundle returns. A stopped bundle must not call any
  87      * Framework objects.
  88      *
  89      * <p>
  90      * This method must complete and return to its caller in a timely manner.
  91      *
  92      * @param context The execution context of the bundle being stopped.
  93      */
  94     protected void stopImpl(final BundleContext context) {
  95         // NOOP
  96     }
  97
  98
  99     protected abstract void onBrokerAvailable(BindingAwareBroker broker, BundleContext context);
 100
 101     protected void onBrokerRemoved(final BindingAwareBroker broker, final BundleContext context) {
 102         stopImpl(context);
 103     }
 104 }