opendaylight/md-sal/samples/toaster-provider/src/main/java/org/opendaylight/controller/sample/toaster/provider/OpendaylightToaster.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.sample.toaster.provider;
   9
  10 import java.util.concurrent.Callable;
  11 import java.util.concurrent.ExecutionException;
  12 import java.util.concurrent.ExecutorService;
  13 import java.util.concurrent.Executors;
  14 import java.util.concurrent.Future;
  15 import java.util.concurrent.atomic.AtomicLong;
  16 import java.util.concurrent.atomic.AtomicReference;
  17
  18 import org.opendaylight.controller.config.yang.config.toaster_provider.impl.ToasterProviderRuntimeMXBean;
  19 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
  20 import org.opendaylight.controller.md.sal.binding.api.DataChangeListener;
  21 import org.opendaylight.controller.md.sal.binding.api.ReadWriteTransaction;
  22 import org.opendaylight.controller.md.sal.binding.api.WriteTransaction;
  23 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeEvent;
  24 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  25 import org.opendaylight.controller.md.sal.common.api.data.OptimisticLockFailedException;
  26 import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
  27 import org.opendaylight.controller.sal.binding.api.NotificationProviderService;
  28 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.DisplayString;
  29 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.MakeToastInput;
  30 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.RestockToasterInput;
  31 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.Toaster;
  32 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.Toaster.ToasterStatus;
  33 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.ToasterBuilder;
  34 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.ToasterOutOfBreadBuilder;
  35 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.ToasterRestocked;
  36 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.ToasterRestockedBuilder;
  37 import org.opendaylight.yang.gen.v1.http.netconfcentral.org.ns.toaster.rev091120.ToasterService;
  38 import org.opendaylight.yangtools.yang.binding.DataObject;
  39 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  40 import org.opendaylight.yangtools.yang.common.RpcError;
  41 import org.opendaylight.yangtools.yang.common.RpcResultBuilder;
  42 import org.opendaylight.yangtools.yang.common.RpcError.ErrorType;
  43 import org.opendaylight.yangtools.yang.common.RpcResult;
  44 import org.slf4j.Logger;
  45 import org.slf4j.LoggerFactory;
  46
  47 import com.google.common.base.Function;
  48 import com.google.common.base.Optional;
  49 import com.google.common.util.concurrent.AsyncFunction;
  50 import com.google.common.util.concurrent.FutureCallback;
  51 import com.google.common.util.concurrent.Futures;
  52 import com.google.common.util.concurrent.ListenableFuture;
  53 import com.google.common.util.concurrent.SettableFuture;
  54
  55 public class OpendaylightToaster implements ToasterService, ToasterProviderRuntimeMXBean,
  56                                             DataChangeListener, AutoCloseable {
  57
  58     private static final Logger LOG = LoggerFactory.getLogger(OpendaylightToaster.class);
  59
  60     public static final InstanceIdentifier<Toaster> TOASTER_IID = InstanceIdentifier.builder(Toaster.class).build();
  61
  62     private static final DisplayString TOASTER_MANUFACTURER = new DisplayString("Opendaylight");
  63     private static final DisplayString TOASTER_MODEL_NUMBER = new DisplayString("Model 1 - Binding Aware");
  64
  65     private NotificationProviderService notificationProvider;
  66     private DataBroker dataProvider;
  67
  68     private final ExecutorService executor;
  69
  70     // The following holds the Future for the current make toast task.
  71     // This is used to cancel the current toast.
  72     private final AtomicReference<Future<?>> currentMakeToastTask = new AtomicReference<>();
  73
  74     private final AtomicLong amountOfBreadInStock = new AtomicLong( 100 );
  75
  76     private final AtomicLong toastsMade = new AtomicLong(0);
  77
  78     // Thread safe holder for our darkness multiplier.
  79     private final AtomicLong darknessFactor = new AtomicLong( 1000 );
  80
  81     public OpendaylightToaster() {
  82         executor = Executors.newFixedThreadPool(1);
  83     }
  84
  85     public void setNotificationProvider(final NotificationProviderService salService) {
  86         this.notificationProvider = salService;
  87     }
  88
  89     public void setDataProvider(final DataBroker salDataProvider) {
  90         this.dataProvider = salDataProvider;
  91         setToasterStatusUp( null );
  92     }
  93
  94     /**
  95      * Implemented from the AutoCloseable interface.
  96      */
  97     @Override
  98     public void close() throws ExecutionException, InterruptedException {
  99         // When we close this service we need to shutdown our executor!
 100         executor.shutdown();
 101
 102         if (dataProvider != null) {
 103             WriteTransaction tx = dataProvider.newWriteOnlyTransaction();
 104             tx.delete(LogicalDatastoreType.OPERATIONAL,TOASTER_IID);
 105             Futures.addCallback( tx.submit(), new FutureCallback<Void>() {
 106                 @Override
 107                 public void onSuccess( final Void result ) {
 108                     LOG.debug( "Delete Toaster commit result: " + result );
 109                 }
 110
 111                 @Override
 112                 public void onFailure( final Throwable t ) {
 113                     LOG.error( "Delete of Toaster failed", t );
 114                 }
 115             } );
 116         }
 117     }
 118
 119     private Toaster buildToaster( final ToasterStatus status ) {
 120
 121         // note - we are simulating a device whose manufacture and model are
 122         // fixed (embedded) into the hardware.
 123         // This is why the manufacture and model number are hardcoded.
 124         return new ToasterBuilder().setToasterManufacturer( TOASTER_MANUFACTURER )
 125                                    .setToasterModelNumber( TOASTER_MODEL_NUMBER )
 126                                    .setToasterStatus( status )
 127                                    .build();
 128     }
 129
 130     /**
 131      * Implemented from the DataChangeListener interface.
 132      */
 133     @Override
 134     public void onDataChanged( final AsyncDataChangeEvent<InstanceIdentifier<?>, DataObject> change ) {
 135         DataObject dataObject = change.getUpdatedSubtree();
 136         if( dataObject instanceof Toaster )
 137         {
 138             Toaster toaster = (Toaster) dataObject;
 139             Long darkness = toaster.getDarknessFactor();
 140             if( darkness != null )
 141             {
 142                 darknessFactor.set( darkness );
 143             }
 144         }
 145     }
 146
 147     /**
 148      * RPC call implemented from the ToasterService interface that cancels the current
 149      * toast, if any.
 150      */
 151     @Override
 152     public Future<RpcResult<Void>> cancelToast() {
 153
 154         Future<?> current = currentMakeToastTask.getAndSet( null );
 155         if( current != null ) {
 156             current.cancel( true );
 157         }
 158
 159         // Always return success from the cancel toast call.
 160         return Futures.immediateFuture( RpcResultBuilder.<Void> success().build() );
 161     }
 162
 163     /**
 164      * RPC call implemented from the ToasterService interface that attempts to make toast.
 165      */
 166     @Override
 167     public Future<RpcResult<Void>> makeToast(final MakeToastInput input) {
 168         LOG.info("makeToast: " + input);
 169
 170         final SettableFuture<RpcResult<Void>> futureResult = SettableFuture.create();
 171
 172         checkStatusAndMakeToast( input, futureResult, 2 );
 173
 174         return futureResult;
 175     }
 176
 177     private RpcError makeToasterOutOfBreadError() {
 178         return RpcResultBuilder.newError( ErrorType.APPLICATION, "resource-denied",
 179                 "Toaster is out of bread", "out-of-stock", null, null );
 180     }
 181
 182     private RpcError makeToasterInUseError() {
 183         return RpcResultBuilder.newWarning( ErrorType.APPLICATION, "in-use",
 184                 "Toaster is busy", null, null, null );
 185     }
 186
 187     private void checkStatusAndMakeToast( final MakeToastInput input,
 188                                           final SettableFuture<RpcResult<Void>> futureResult,
 189                                           final int tries ) {
 190
 191         // Read the ToasterStatus and, if currently Up, try to write the status to Down.
 192         // If that succeeds, then we essentially have an exclusive lock and can proceed
 193         // to make toast.
 194
 195         final ReadWriteTransaction tx = dataProvider.newReadWriteTransaction();
 196         ListenableFuture<Optional<Toaster>> readFuture =
 197                                           tx.read( LogicalDatastoreType.OPERATIONAL, TOASTER_IID );
 198
 199         final ListenableFuture<Void> commitFuture =
 200             Futures.transform( readFuture, new AsyncFunction<Optional<Toaster>,Void>() {
 201
 202                 @Override
 203                 public ListenableFuture<Void> apply(
 204                         final Optional<Toaster> toasterData ) throws Exception {
 205
 206                     ToasterStatus toasterStatus = ToasterStatus.Up;
 207                     if( toasterData.isPresent() ) {
 208                         toasterStatus = toasterData.get().getToasterStatus();
 209                     }
 210
 211                     LOG.debug( "Read toaster status: {}", toasterStatus );
 212
 213                     if( toasterStatus == ToasterStatus.Up ) {
 214
 215                         if( outOfBread() ) {
 216                             LOG.debug( "Toaster is out of bread" );
 217
 218                             return Futures.immediateFailedCheckedFuture(
 219                                     new TransactionCommitFailedException( "", makeToasterOutOfBreadError() ) );
 220                         }
 221
 222                         LOG.debug( "Setting Toaster status to Down" );
 223
 224                         // We're not currently making toast - try to update the status to Down
 225                         // to indicate we're going to make toast. This acts as a lock to prevent
 226                         // concurrent toasting.
 227                         tx.put( LogicalDatastoreType.OPERATIONAL, TOASTER_IID,
 228                                 buildToaster( ToasterStatus.Down ) );
 229                         return tx.submit();
 230                     }
 231
 232                     LOG.debug( "Oops - already making toast!" );
 233
 234                     // Return an error since we are already making toast. This will get
 235                     // propagated to the commitFuture below which will interpret the null
 236                     // TransactionStatus in the RpcResult as an error condition.
 237                     return Futures.immediateFailedCheckedFuture(
 238                             new TransactionCommitFailedException( "", makeToasterInUseError() ) );
 239                 }
 240         } );
 241
 242         Futures.addCallback( commitFuture, new FutureCallback<Void>() {
 243             @Override
 244             public void onSuccess( final Void result ) {
 245                 // OK to make toast
 246                 currentMakeToastTask.set( executor.submit( new MakeToastTask( input, futureResult ) ) );
 247             }
 248
 249             @Override
 250             public void onFailure( final Throwable ex ) {
 251                 if( ex instanceof OptimisticLockFailedException ) {
 252
 253                     // Another thread is likely trying to make toast simultaneously and updated the
 254                     // status before us. Try reading the status again - if another make toast is
 255                     // now in progress, we should get ToasterStatus.Down and fail.
 256
 257                     if( ( tries - 1 ) > 0 ) {
 258                         LOG.debug( "Got OptimisticLockFailedException - trying again" );
 259
 260                         checkStatusAndMakeToast( input, futureResult, tries - 1 );
 261                     }
 262                     else {
 263                         futureResult.set( RpcResultBuilder.<Void> failed()
 264                                 .withError( ErrorType.APPLICATION, ex.getMessage() ).build() );
 265                     }
 266
 267                 } else {
 268
 269                     LOG.debug( "Failed to commit Toaster status", ex );
 270
 271                     // Probably already making toast.
 272                     futureResult.set( RpcResultBuilder.<Void> failed()
 273                             .withRpcErrors( ((TransactionCommitFailedException)ex).getErrorList() )
 274                             .build() );
 275                 }
 276             }
 277         } );
 278     }
 279
 280     /**
 281      * RestConf RPC call implemented from the ToasterService interface.
 282      * Restocks the bread for the toaster, resets the toastsMade counter to 0, and sends a
 283      * ToasterRestocked notification.
 284      */
 285     @Override
 286     public Future<RpcResult<java.lang.Void>> restockToaster(final RestockToasterInput input) {
 287         LOG.info( "restockToaster: " + input );
 288
 289         amountOfBreadInStock.set( input.getAmountOfBreadToStock() );
 290
 291         if( amountOfBreadInStock.get() > 0 ) {
 292             ToasterRestocked reStockedNotification = new ToasterRestockedBuilder()
 293                 .setAmountOfBread( input.getAmountOfBreadToStock() ).build();
 294             notificationProvider.publish( reStockedNotification );
 295         }
 296
 297         return Futures.immediateFuture( RpcResultBuilder.<Void> success().build() );
 298     }
 299
 300     /**
 301      * JMX RPC call implemented from the ToasterProviderRuntimeMXBean interface.
 302      */
 303     @Override
 304     public void clearToastsMade() {
 305         LOG.info( "clearToastsMade" );
 306         toastsMade.set( 0 );
 307     }
 308
 309     /**
 310      * Accesssor method implemented from the ToasterProviderRuntimeMXBean interface.
 311      */
 312     @Override
 313     public Long getToastsMade() {
 314         return toastsMade.get();
 315     }
 316
 317     private void setToasterStatusUp( final Function<Boolean,Void> resultCallback ) {
 318
 319         WriteTransaction tx = dataProvider.newWriteOnlyTransaction();
 320         tx.put( LogicalDatastoreType.OPERATIONAL,TOASTER_IID, buildToaster( ToasterStatus.Up ) );
 321
 322         Futures.addCallback( tx.submit(), new FutureCallback<Void>() {
 323             @Override
 324             public void onSuccess( final Void result ) {
 325                 notifyCallback( true );
 326             }
 327
 328             @Override
 329             public void onFailure( final Throwable t ) {
 330                 // We shouldn't get an OptimisticLockFailedException (or any ex) as no
 331                 // other component should be updating the operational state.
 332                 LOG.error( "Failed to update toaster status", t );
 333
 334                 notifyCallback( false );
 335             }
 336
 337             void notifyCallback( final boolean result ) {
 338                 if( resultCallback != null ) {
 339                     resultCallback.apply( result );
 340                 }
 341             }
 342         } );
 343     }
 344
 345     private boolean outOfBread()
 346     {
 347         return amountOfBreadInStock.get() == 0;
 348     }
 349
 350     private class MakeToastTask implements Callable<Void> {
 351
 352         final MakeToastInput toastRequest;
 353         final SettableFuture<RpcResult<Void>> futureResult;
 354
 355         public MakeToastTask( final MakeToastInput toastRequest,
 356                               final SettableFuture<RpcResult<Void>> futureResult ) {
 357             this.toastRequest = toastRequest;
 358             this.futureResult = futureResult;
 359         }
 360
 361         @Override
 362         public Void call() {
 363             try
 364             {
 365                 // make toast just sleeps for n seconds per doneness level.
 366                 long darknessFactor = OpendaylightToaster.this.darknessFactor.get();
 367                 Thread.sleep(darknessFactor * toastRequest.getToasterDoneness());
 368
 369             }
 370             catch( InterruptedException e ) {
 371                 LOG.info( "Interrupted while making the toast" );
 372             }
 373
 374             toastsMade.incrementAndGet();
 375
 376             amountOfBreadInStock.getAndDecrement();
 377             if( outOfBread() ) {
 378                 LOG.info( "Toaster is out of bread!" );
 379
 380                 notificationProvider.publish( new ToasterOutOfBreadBuilder().build() );
 381             }
 382
 383             // Set the Toaster status back to up - this essentially releases the toasting lock.
 384             // We can't clear the current toast task nor set the Future result until the
 385             // update has been committed so we pass a callback to be notified on completion.
 386
 387             setToasterStatusUp( new Function<Boolean,Void>() {
 388                 @Override
 389                 public Void apply( final Boolean result ) {
 390
 391                     currentMakeToastTask.set( null );
 392
 393                     LOG.debug("Toast done");
 394
 395                     futureResult.set( RpcResultBuilder.<Void>success().build() );
 396
 397                     return null;
 398                 }
 399             } );
 400
 401             return null;
 402         }
 403     }
 404 }