opendaylight/sal/api/src/main/java/org/opendaylight/controller/sal/core/ComponentActivatorAbstractBase.java

   1
   2 /*
   3  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   4  *
   5  * This program and the accompanying materials are made available under the
   6  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   7  * and is available at http://www.eclipse.org/legal/epl-v10.html
   8  */
   9
  10 package org.opendaylight.controller.sal.core;
  11
  12 /**
  13  * @file   ComponentActivatorAbstractBase.java
  14  *
  15  * @brief  Abstract class which need to be subclassed in order to
  16  * track and register dependencies per-container
  17  *
  18  * Abstract class which need to be subclassed in order to
  19  * track and register dependencies per-container
  20  *
  21  */
  22
  23 import java.util.Dictionary;
  24 import java.util.Hashtable;
  25 import java.util.concurrent.ConcurrentHashMap;
  26 import java.util.concurrent.ConcurrentMap;
  27
  28 import org.apache.commons.lang3.tuple.ImmutablePair;
  29 import org.apache.felix.dm.Component;
  30 import org.apache.felix.dm.ComponentStateListener;
  31 import org.apache.felix.dm.DependencyManager;
  32 import org.apache.felix.dm.ServiceDependency;
  33 import org.osgi.framework.BundleActivator;
  34 import org.osgi.framework.BundleContext;
  35 import org.osgi.framework.ServiceRegistration;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 /**
  40  * Abstract class which need to be subclassed in order to track and
  41  * register dependencies per-container
  42  *
  43  */
  44 abstract public class ComponentActivatorAbstractBase implements
  45         BundleActivator, IContainerAware {
  46     Logger logger = LoggerFactory
  47             .getLogger(ComponentActivatorAbstractBase.class);
  48     private ServiceRegistration containerAwareRegistration;
  49     private DependencyManager dm;
  50     private ConcurrentMap<ImmutablePair<String, Object>, Component> dbInstances = (ConcurrentMap<ImmutablePair<String, Object>, Component>) new ConcurrentHashMap<ImmutablePair<String, Object>, Component>();
  51     private ConcurrentMap<Object, Component> dbGlobalInstances = (ConcurrentMap<Object, Component>) new ConcurrentHashMap<Object, Component>();
  52
  53     /**
  54      * Abstract method that MUST be implemented by the derived class
  55      * that wants to activate the Component bundle in a container. Here
  56      * customization for the component are expected
  57      */
  58     abstract protected void init();
  59
  60     /**
  61      * Abstract method that MUST be implemented by the derived class
  62      * that wants to DE-activate the Component bundle in a container. Here
  63      * customization for the component are expected
  64      */
  65     abstract protected void destroy();
  66
  67     /**
  68      * Method which tells how many implementations are supported by
  69      * the bundle. This way we can tune the number of components
  70      * created.
  71      *
  72      *
  73      * @return The list of implementations the bundle will support,
  74      * this will be used to decide how many components need to be
  75      * created per-container
  76      */
  77     protected Object[] getImplementations() {
  78         return null;
  79     }
  80
  81     /**
  82      * Method which tells how many Global implementations are
  83      * supported by the bundle. This way we can tune the number of
  84      * components created. This components will be created ONLY at the
  85      * time of bundle startup and will be destroyed only at time of
  86      * bundle destruction, this is the major difference with the
  87      * implementation retrieved via getImplementations where all of
  88      * them are assumed to be in a container!
  89      *
  90      *
  91      * @return The list of implementations the bundle will support,
  92      * in Global version
  93      */
  94     protected Object[] getGlobalImplementations() {
  95         return null;
  96     }
  97
  98     /**
  99      * Configure the dependency for a given instance inside a container
 100      *
 101      * @param c Component assigned for this instance, this will be
 102      * what will be used for configuration
 103      * @param imp implementation to be configured
 104      * @param containerName container on which the configuration happens
 105      */
 106     protected void configureInstance(Component c, Object imp,
 107             String containerName) {
 108         // do nothing by default
 109     }
 110
 111     /**
 112      * Configure the dependency for a given instance Global
 113      *
 114      * @param c Component assigned for this instance, this will be
 115      * what will be used for configuration
 116      * @param imp implementation to be configured
 117      * @param containerName container on which the configuration happens
 118      */
 119     protected void configureGlobalInstance(Component c, Object imp) {
 120         // Do nothing by default
 121     }
 122
 123     // Private class used to listen to state transition so we can
 124     // implement the necessary logic to call "started" and "stopping"
 125     // methods on the component. Right now the framework natively
 126     // support only the call of:
 127     // - "init": Called after dependency are satisfied
 128     // - "start": Called after init but before services are registered
 129     // - "stop": Called after services are unregistered but before the
 130     // component is going to be destroyed
 131     // - "destroy": Called to destroy the component.
 132     // There is still a need for two notifications:
 133     // - "started" method to be called after "start" and after the
 134     // services has been registered in the OSGi service registry
 135     // - "stopping" method to be called before "stop" method and
 136     // before the services of the component are removed from OSGi
 137     // service registry
 138     class ListenerComponentStates implements ComponentStateListener {
 139         @Override
 140         public void starting(Component component) {
 141             // do nothing
 142         }
 143
 144         @Override
 145         public void started(Component component) {
 146             if (component == null) {
 147                 return;
 148             }
 149             component.invokeCallbackMethod(new Object[] { component
 150                     .getService() }, "started", new Class[][] {
 151                     { Component.class }, {} }, new Object[][] { { component },
 152                     {} });
 153         }
 154
 155         @Override
 156         public void stopped(Component component) {
 157             if (component == null) {
 158                 return;
 159             }
 160             component.invokeCallbackMethod(new Object[] { component
 161                     .getService() }, "stopping", new Class[][] {
 162                     { Component.class }, {} }, new Object[][] { { component },
 163                     {} });
 164         }
 165
 166         @Override
 167         public void stopping(Component component) {
 168             // do nothing
 169         }
 170     }
 171
 172     /**
 173      * Method of IContainerAware called when a new container is available
 174      *
 175      * @param containerName Container being created
 176      */
 177     @Override
 178     public void containerCreate(String containerName) {
 179         try {
 180             Object[] imps = getImplementations();
 181             logger.trace("Creating instance {}", containerName);
 182             if (imps != null) {
 183                 for (int i = 0; i < imps.length; i++) {
 184                     ImmutablePair<String, Object> key = new ImmutablePair<String, Object>(
 185                             containerName, imps[i]);
 186                     Component c = this.dbInstances.get(key);
 187                     if (c == null) {
 188                         c = this.dm.createComponent();
 189                         c.addStateListener(new ListenerComponentStates());
 190                         // Now let the derived class to configure the
 191                         // dependencies it wants
 192                         configureInstance(c, imps[i], containerName);
 193                         // Set the implementation so the component can manage
 194                         // its lifecycle
 195                         if (c.getService() == null) {
 196                             logger.trace("Setting implementation to: {}",
 197                                           imps[i]);
 198                             c.setImplementation(imps[i]);
 199                         }
 200
 201                         //Set the service properties to include the containerName
 202                         //in the service, that is fundamental for supporting
 203                         //multiple services just distinguished via a container
 204                         Dictionary<String, String> serviceProps = c
 205                                 .getServiceProperties();
 206                         if (serviceProps != null) {
 207                             logger.trace("Adding new property for container");
 208                             serviceProps.put("containerName", containerName);
 209                         } else {
 210                             logger
 211                                     .trace("Create a new properties for the service");
 212                             serviceProps = new Hashtable<String, String>();
 213                             serviceProps.put("containerName", containerName);
 214                         }
 215                         c.setServiceProperties(serviceProps);
 216
 217                         // Now add the component to the dependency Manager
 218                         // which will immediately start tracking the dependencies
 219                         this.dm.add(c);
 220
 221                         //Now lets keep track in our shadow database of the
 222                         //association
 223                         this.dbInstances.put(key, c);
 224                     } else {
 225                         logger
 226                                 .error("I have been asked again to create an instance "
 227                                         + "on: "
 228                                         + containerName
 229                                         + "for object: "
 230                                         + imps[i]
 231                                         + "when i already have it!!");
 232                     }
 233                 }
 234             }
 235         } catch (Exception ex) {
 236             logger
 237                     .error("During containerDestroy invocation caught exception: "
 238                             + ex
 239                             + "\nStacktrace:"
 240                             + stackToString(ex.getStackTrace()));
 241         }
 242     }
 243
 244     @Override
 245     public void containerDestroy(String containerName) {
 246         try {
 247             Object[] imps = getImplementations();
 248             logger.trace("Destroying instance {}", containerName);
 249             if (imps != null) {
 250                 for (int i = 0; i < imps.length; i++) {
 251                     ImmutablePair<String, Object> key = new ImmutablePair<String, Object>(
 252                             containerName, imps[i]);
 253                     Component c = this.dbInstances.get(key);
 254                     if (c != null) {
 255                         // Now remove the component from dependency manager,
 256                         // which will implicitely stop it first
 257                         this.dm.remove(c);
 258                     } else {
 259                         logger
 260                                 .error("I have been asked again to remove an instance "
 261                                         + "on: "
 262                                         + containerName
 263                                         + "for object: "
 264                                         + imps[i]
 265                                         + "when i already have cleared it!!");
 266                     }
 267
 268                     //Now lets remove the association from our shadow
 269                     //database so the component can be recycled, this is done
 270                     //unconditionally in case of spurious conditions
 271                     this.dbInstances.remove(key);
 272                 }
 273             }
 274         } catch (Exception ex) {
 275             logger
 276                     .error("During containerDestroy invocation caught exception: "
 277                             + ex
 278                             + "\nStacktrace:"
 279                             + stackToString(ex.getStackTrace()));
 280         }
 281     }
 282
 283     private String stackToString(StackTraceElement[] stack) {
 284         if (stack == null) {
 285             return "<EmptyStack>";
 286         }
 287         StringBuffer buffer = new StringBuffer();
 288
 289         for (int i = 0; i < stack.length; i++) {
 290             buffer.append("\n\t" + stack[i].toString());
 291         }
 292         return buffer.toString();
 293     }
 294
 295     /**
 296      * Method called by the OSGi framework when the OSGi bundle
 297      * starts. The functionality we want to perform here are:
 298      *
 299      * 1) Register with the OSGi framework, that we are a provider of
 300      * IContainerAware service and so in case of startup of a container we
 301      * want to be called
 302      *
 303      * 2) Create data structures that allow to keep track of all the
 304      * instances created per-container given the derived class of
 305      * ComponentActivatorAbstractBase will act as a Factory manager
 306      *
 307      * @param context OSGi bundle context to interact with OSGi framework
 308      */
 309     @Override
 310     public void start(BundleContext context) {
 311         try {
 312             this.dm = new DependencyManager(context);
 313
 314             logger.trace("Activating");
 315
 316             // Now create Global components
 317             Object[] imps = getGlobalImplementations();
 318             if (imps != null) {
 319                 for (int i = 0; i < imps.length; i++) {
 320                     Object key = imps[i];
 321                     Component c = this.dbGlobalInstances.get(key);
 322                     if (c == null) {
 323                         try {
 324                             c = this.dm.createComponent();
 325                             c.addStateListener(new ListenerComponentStates());
 326                             // Now let the derived class to configure the
 327                             // dependencies it wants
 328                             configureGlobalInstance(c, imps[i]);
 329                             // Set the implementation so the component
 330                             // can manage its lifesycle
 331                             if (c.getService() == null) {
 332                                 logger.trace("Setting implementation to: {}",
 333                                         imps[i]);
 334                                 c.setImplementation(imps[i]);
 335                             }
 336
 337                             // Now add the component to the dependency
 338                             // Manager which will immediately start
 339                             // tracking the dependencies
 340                             this.dm.add(c);
 341                         } catch (Exception nex) {
 342                             logger.error("During creation of a Global "
 343                                     + "instance caught exception: " + nex
 344                                     + "\nStacktrace:"
 345                                     + stackToString(nex.getStackTrace()));
 346                         }
 347
 348                         //Now lets keep track in our shadow database of the
 349                         //association
 350                         if (c != null)
 351                             this.dbGlobalInstances.put(key, c);
 352                     } else {
 353                         logger.error("I have been asked again to create an "
 354                                 + "instance " + " Global for object: "
 355                                 + imps[i] + "when i already have it!!");
 356                     }
 357                 }
 358             }
 359
 360             // Register with OSGi the provider for the service IContainerAware
 361             this.containerAwareRegistration = context.registerService(
 362                     IContainerAware.class.getName(), this, null);
 363
 364             // Now call the derived class init function
 365             this.init();
 366
 367             logger.trace("Activation DONE!");
 368         } catch (Exception ex) {
 369             logger.error("During Activator start caught exception: " + ex
 370                     + "\nStacktrace:" + stackToString(ex.getStackTrace()));
 371         }
 372     }
 373
 374     /**
 375      * Method called by the OSGi framework when the OSGi bundle
 376      * stops. The functionality we want to perform here are:
 377      *
 378      * 1) Force all the instances to stop and do cleanup and
 379      * unreference them so garbage collection can clean them up
 380      *
 381      * NOTE: UN-Register with the OSGi framework,is not needed because
 382      * the framework will automatically do it
 383      *
 384      * @param context OSGi bundle context to interact with OSGi framework
 385      */
 386     @Override
 387     public void stop(BundleContext context) {
 388         try {
 389             logger.trace("DE-Activating");
 390
 391             // Now call the derived class destroy function
 392             this.destroy();
 393
 394             // Now remove all the components tracked for container components
 395             for (ImmutablePair<String, Object> key : this.dbInstances.keySet()) {
 396                 try {
 397                     Component c = this.dbInstances.get(key);
 398                     if (c != null) {
 399                         logger.trace("Remove component on container: {} Object: {}",
 400                                 key.getLeft(), key.getRight());
 401                         this.dm.remove(c);
 402                     }
 403                 } catch (Exception nex) {
 404                     logger.error("During removal of a container component "
 405                             + "instance caught exception: " + nex
 406                             + "\nStacktrace:"
 407                             + stackToString(nex.getStackTrace()));
 408                 }
 409                 this.dbInstances.remove(key);
 410             }
 411
 412             // Now remove all the components tracked for Global Components
 413             for (Object key : this.dbGlobalInstances.keySet()) {
 414                 try {
 415                     Component c = this.dbGlobalInstances.get(key);
 416                     if (c != null) {
 417                         logger.trace("Remove component for Object: {}" , key);
 418                         this.dm.remove(c);
 419                     }
 420                 } catch (Exception nex) {
 421                     logger.error("During removal of a Global "
 422                             + "instance caught exception: " + nex
 423                             + "\nStacktrace:"
 424                             + stackToString(nex.getStackTrace()));
 425                 }
 426
 427                 this.dbGlobalInstances.remove(key);
 428             }
 429
 430             // Detach Dependency Manager
 431             this.dm = null;
 432
 433             logger.trace("Deactivation DONE!");
 434         } catch (Exception ex) {
 435             logger.error("During Activator stop caught exception: " + ex
 436                     + "\nStacktrace:" + stackToString(ex.getStackTrace()));
 437         }
 438     }
 439
 440     /**
 441      * Return a ServiceDependency customized ad hoc for slicing, this
 442      * essentially the same org.apache.felix.dm.ServiceDependency just
 443      * with some filters pre-set
 444      *
 445      * @param containerName containerName for which we want to create the dependency
 446      *
 447      * @return a ServiceDependency
 448      */
 449     protected ServiceDependency createContainerServiceDependency(
 450             String containerName) {
 451         return (new ContainerServiceDependency(this.dm, containerName));
 452     }
 453
 454     /**
 455      * Return a ServiceDependency as provided by Dependency Manager as it's
 456      *
 457      *
 458      * @return a ServiceDependency
 459      */
 460     protected ServiceDependency createServiceDependency() {
 461         return this.dm.createServiceDependency();
 462     }
 463 }