X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsamples%2Ftoaster-provider%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fsample%2Ftoaster%2Fprovider%2FOpendaylightToaster.java;h=d2b0f90194a9a066558f6d4dca5d1d8751ec01aa;hp=ec352e8f510dad03911be2ad2eeb0ec6a5c44542;hb=dddc5c7faaa4991535e56c8b16c9ecb2f5303ab0;hpb=7d753ff9887cb803bdcd222aec2ab2a0a9c87906 diff --git a/opendaylight/md-sal/samples/toaster-provider/src/main/java/org/opendaylight/controller/sample/toaster/provider/OpendaylightToaster.java b/opendaylight/md-sal/samples/toaster-provider/src/main/java/org/opendaylight/controller/sample/toaster/provider/OpendaylightToaster.java index ec352e8f51..d2b0f90194 100644 --- a/opendaylight/md-sal/samples/toaster-provider/src/main/java/org/opendaylight/controller/sample/toaster/provider/OpendaylightToaster.java +++ b/opendaylight/md-sal/samples/toaster-provider/src/main/java/org/opendaylight/controller/sample/toaster/provider/OpendaylightToaster.java @@ -9,19 +9,24 @@ package org.opendaylight.controller.sample.toaster.provider; import java.util.Arrays; import java.util.Collections; +import java.util.List; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; import java.util.concurrent.atomic.AtomicLong; +import java.util.concurrent.atomic.AtomicReference; import org.opendaylight.controller.config.yang.config.toaster_provider.impl.ToasterProviderRuntimeMXBean; import org.opendaylight.controller.md.sal.binding.api.DataBroker; import org.opendaylight.controller.md.sal.binding.api.DataChangeListener; +import org.opendaylight.controller.md.sal.binding.api.ReadWriteTransaction; import org.opendaylight.controller.md.sal.binding.api.WriteTransaction; +import org.opendaylight.controller.md.sal.common.api.TransactionStatus; import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeEvent; import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType; +import org.opendaylight.controller.md.sal.common.api.data.OptimisticLockFailedException; import org.opendaylight.controller.sal.binding.api.NotificationProviderService; import org.opendaylight.controller.sal.common.util.RpcErrors; import org.opendaylight.controller.sal.common.util.Rpcs; @@ -44,7 +49,13 @@ import org.opendaylight.yangtools.yang.common.RpcResult; import org.slf4j.Logger; import org.slf4j.LoggerFactory; +import com.google.common.base.Function; +import com.google.common.base.Optional; +import com.google.common.util.concurrent.AsyncFunction; +import com.google.common.util.concurrent.FutureCallback; import com.google.common.util.concurrent.Futures; +import com.google.common.util.concurrent.ListenableFuture; +import com.google.common.util.concurrent.SettableFuture; public class OpendaylightToaster implements ToasterService, ToasterProviderRuntimeMXBean, DataChangeListener, AutoCloseable { @@ -61,10 +72,9 @@ public class OpendaylightToaster implements ToasterService, ToasterProviderRunti private final ExecutorService executor; - // As you will see we are using multiple threads here. Therefore we need to be careful about concurrency. - // In this case we use the taskLock to provide synchronization for the current task. - private volatile Future> currentTask; - private final Object taskLock = new Object(); + // The following holds the Future for the current make toast task. + // This is used to cancel the current toast. + private final AtomicReference> currentMakeToastTask = new AtomicReference<>(); private final AtomicLong amountOfBreadInStock = new AtomicLong( 100 ); @@ -83,7 +93,7 @@ public class OpendaylightToaster implements ToasterService, ToasterProviderRunti public void setDataProvider(final DataBroker salDataProvider) { this.dataProvider = salDataProvider; - updateStatus(); + setToasterStatusUp( null ); } /** @@ -97,22 +107,30 @@ public class OpendaylightToaster implements ToasterService, ToasterProviderRunti if (dataProvider != null) { WriteTransaction t = dataProvider.newWriteOnlyTransaction(); t.delete(LogicalDatastoreType.OPERATIONAL,TOASTER_IID); - t.commit().get(); // FIXME: This call should not be blocking. + ListenableFuture> future = t.commit(); + Futures.addCallback( future, new FutureCallback>() { + @Override + public void onSuccess( RpcResult result ) { + LOG.debug( "Delete Toaster commit result: " + result ); + } + + @Override + public void onFailure( Throwable t ) { + LOG.error( "Delete of Toaster failed", t ); + } + } ); } } - private Toaster buildToaster() { - // We don't need to synchronize on currentTask here b/c it's declared volatile and - // we're just doing a read. - boolean isUp = currentTask == null; + private Toaster buildToaster( ToasterStatus status ) { // note - we are simulating a device whose manufacture and model are // fixed (embedded) into the hardware. // This is why the manufacture and model number are hardcoded. - ToasterBuilder tb = new ToasterBuilder(); - tb.setToasterManufacturer(TOASTER_MANUFACTURER).setToasterModelNumber(TOASTER_MODEL_NUMBER) - .setToasterStatus(isUp ? ToasterStatus.Up : ToasterStatus.Down); - return tb.build(); + return new ToasterBuilder().setToasterManufacturer( TOASTER_MANUFACTURER ) + .setToasterModelNumber( TOASTER_MODEL_NUMBER ) + .setToasterStatus( status ) + .build(); } /** @@ -133,57 +151,148 @@ public class OpendaylightToaster implements ToasterService, ToasterProviderRunti } /** - * RestConf RPC call implemented from the ToasterService interface. + * RPC call implemented from the ToasterService interface that cancels the current + * toast, if any. */ @Override public Future> cancelToast() { - synchronized (taskLock) { - if (currentTask != null) { - currentTask.cancel(true); - currentTask = null; - } + + Future current = currentMakeToastTask.getAndSet( null ); + if( current != null ) { + current.cancel( true ); } + // Always return success from the cancel toast call. - return Futures.immediateFuture(Rpcs. getRpcResult(true, Collections. emptySet())); + return Futures.immediateFuture( Rpcs. getRpcResult( true, + Collections.emptyList() ) ); } /** - * RestConf RPC call implemented from the ToasterService interface. + * RPC call implemented from the ToasterService interface that attempts to make toast. */ @Override public Future> makeToast(final MakeToastInput input) { LOG.info("makeToast: " + input); - synchronized (taskLock) { - if (currentTask != null) { - // return an error since we are already toasting some toast. - LOG.info( "Toaster is already making toast" ); + final SettableFuture> futureResult = SettableFuture.create(); - RpcResult result = Rpcs. getRpcResult(false, null, Arrays.asList( - RpcErrors.getRpcError( "", "in-use", null, ErrorSeverity.WARNING, - "Toaster is busy", ErrorType.APPLICATION, null ) ) ); - return Futures.immediateFuture(result); - } - else if( outOfBread() ) { - RpcResult result = Rpcs. getRpcResult(false, null, Arrays.asList( - RpcErrors.getRpcError( "out-of-stock", "resource-denied", null, null, - "Toaster is out of bread", - ErrorType.APPLICATION, null ) ) ); - return Futures.immediateFuture(result); - } - else { - // Notice that we are moving the actual call to another thread, - // allowing this thread to return immediately. - // The MD-SAL design encourages asynchronus programming. If the - // caller needs to block until the call is - // complete then they can leverage the blocking methods on the - // Future interface. - currentTask = executor.submit(new MakeToastTask(input)); + checkStatusAndMakeToast( input, futureResult ); + + return futureResult; + } + + private List makeToasterOutOfBreadError() { + return Arrays.asList( + RpcErrors.getRpcError( "out-of-stock", "resource-denied", null, null, + "Toaster is out of bread", + ErrorType.APPLICATION, null ) ); + } + + private List makeToasterInUseError() { + return Arrays.asList( + RpcErrors.getRpcError( "", "in-use", null, ErrorSeverity.WARNING, + "Toaster is busy", ErrorType.APPLICATION, null ) ); + } + + private void checkStatusAndMakeToast( final MakeToastInput input, + final SettableFuture> futureResult ) { + + // Read the ToasterStatus and, if currently Up, try to write the status to Down. + // If that succeeds, then we essentially have an exclusive lock and can proceed + // to make toast. + + final ReadWriteTransaction tx = dataProvider.newReadWriteTransaction(); + ListenableFuture> readFuture = + tx.read( LogicalDatastoreType.OPERATIONAL, TOASTER_IID ); + + final ListenableFuture> commitFuture = + Futures.transform( readFuture, new AsyncFunction, + RpcResult>() { + + @Override + public ListenableFuture> apply( + Optional toasterData ) throws Exception { + + ToasterStatus toasterStatus = ToasterStatus.Up; + if( toasterData.isPresent() ) { + toasterStatus = ((Toaster)toasterData.get()).getToasterStatus(); + } + + LOG.debug( "Read toaster status: {}", toasterStatus ); + + if( toasterStatus == ToasterStatus.Up ) { + + if( outOfBread() ) { + LOG.debug( "Toaster is out of bread" ); + + return Futures.immediateFuture( Rpcs.getRpcResult( + false, null, makeToasterOutOfBreadError() ) ); + } + + LOG.debug( "Setting Toaster status to Down" ); + + // We're not currently making toast - try to update the status to Down + // to indicate we're going to make toast. This acts as a lock to prevent + // concurrent toasting. + tx.put( LogicalDatastoreType.OPERATIONAL, TOASTER_IID, + buildToaster( ToasterStatus.Down ) ); + return tx.commit(); + } + + LOG.debug( "Oops - already making toast!" ); + + // Return an error since we are already making toast. This will get + // propagated to the commitFuture below which will interpret the null + // TransactionStatus in the RpcResult as an error condition. + return Futures.immediateFuture( Rpcs.getRpcResult( + false, null, makeToasterInUseError() ) ); + } + } ); + + Futures.addCallback( commitFuture, new FutureCallback>() { + @Override + public void onSuccess( RpcResult result ) { + if( result.getResult() == TransactionStatus.COMMITED ) { + + // OK to make toast + currentMakeToastTask.set( executor.submit( + new MakeToastTask( input, futureResult ) ) ); + } else { + + LOG.debug( "Setting error result" ); + + // Either the transaction failed to commit for some reason or, more likely, + // the read above returned ToasterStatus.Down. Either way, fail the + // futureResult and copy the errors. + + futureResult.set( Rpcs.getRpcResult( false, null, result.getErrors() ) ); + } } - } - updateStatus(); - return currentTask; + @Override + public void onFailure( Throwable ex ) { + if( ex instanceof OptimisticLockFailedException ) { + + // Another thread is likely trying to make toast simultaneously and updated the + // status before us. Try reading the status again - if another make toast is + // now in progress, we should get ToasterStatus.Down and fail. + + LOG.debug( "Got OptimisticLockFailedException - trying again" ); + + checkStatusAndMakeToast( input, futureResult ); + + } else { + + LOG.error( "Failed to commit Toaster status", ex ); + + // Got some unexpected error so fail. + futureResult.set( Rpcs. getRpcResult( false, null, Arrays.asList( + RpcErrors.getRpcError( null, null, null, ErrorSeverity.ERROR, + ex.getMessage(), + ErrorType.APPLICATION, ex ) ) ) ); + } + } + } ); } /** @@ -195,17 +304,15 @@ public class OpendaylightToaster implements ToasterService, ToasterProviderRunti public Future> restockToaster(final RestockToasterInput input) { LOG.info( "restockToaster: " + input ); - synchronized( taskLock ) { - amountOfBreadInStock.set( input.getAmountOfBreadToStock() ); + amountOfBreadInStock.set( input.getAmountOfBreadToStock() ); - if( amountOfBreadInStock.get() > 0 ) { - ToasterRestocked reStockedNotification = - new ToasterRestockedBuilder().setAmountOfBread( input.getAmountOfBreadToStock() ).build(); - notificationProvider.publish( reStockedNotification ); - } + if( amountOfBreadInStock.get() > 0 ) { + ToasterRestocked reStockedNotification = new ToasterRestockedBuilder() + .setAmountOfBread( input.getAmountOfBreadToStock() ).build(); + notificationProvider.publish( reStockedNotification ); } - return Futures.immediateFuture(Rpcs. getRpcResult(true, Collections. emptySet())); + return Futures.immediateFuture(Rpcs. getRpcResult(true, Collections.emptyList())); } /** @@ -225,19 +332,38 @@ public class OpendaylightToaster implements ToasterService, ToasterProviderRunti return toastsMade.get(); } - private void updateStatus() { - if (dataProvider != null) { - WriteTransaction tx = dataProvider.newWriteOnlyTransaction(); - tx.put(LogicalDatastoreType.OPERATIONAL,TOASTER_IID, buildToaster()); + private void setToasterStatusUp( final Function resultCallback ) { - try { - tx.commit().get(); - } catch (InterruptedException | ExecutionException e) { - LOG.warn("Failed to update toaster status, operational otherwise", e); + WriteTransaction tx = dataProvider.newWriteOnlyTransaction(); + tx.put( LogicalDatastoreType.OPERATIONAL,TOASTER_IID, buildToaster( ToasterStatus.Up ) ); + + ListenableFuture> commitFuture = tx.commit(); + + Futures.addCallback( commitFuture, new FutureCallback>() { + @Override + public void onSuccess( RpcResult result ) { + if( result.getResult() != TransactionStatus.COMMITED ) { + LOG.error( "Failed to update toaster status: " + result.getErrors() ); + } + + notifyCallback( result.getResult() == TransactionStatus.COMMITED ); } - } else { - LOG.trace("No data provider configured, not updating status"); - } + + @Override + public void onFailure( Throwable t ) { + // We shouldn't get an OptimisticLockFailedException (or any ex) as no + // other component should be updating the operational state. + LOG.error( "Failed to update toaster status", t ); + + notifyCallback( false ); + } + + void notifyCallback( boolean result ) { + if( resultCallback != null ) { + resultCallback.apply( result ); + } + } + } ); } private boolean outOfBread() @@ -245,19 +371,22 @@ public class OpendaylightToaster implements ToasterService, ToasterProviderRunti return amountOfBreadInStock.get() == 0; } - private class MakeToastTask implements Callable> { + private class MakeToastTask implements Callable { final MakeToastInput toastRequest; + final SettableFuture> futureResult; - public MakeToastTask(final MakeToastInput toast) { - toastRequest = toast; + public MakeToastTask( final MakeToastInput toastRequest, + final SettableFuture> futureResult ) { + this.toastRequest = toastRequest; + this.futureResult = futureResult; } @Override - public RpcResult call() { + public Void call() { try { - // make toast just sleeps for n secondn per doneness level. + // make toast just sleeps for n seconds per doneness level. long darknessFactor = OpendaylightToaster.this.darknessFactor.get(); Thread.sleep(darknessFactor * toastRequest.getToasterDoneness()); @@ -275,15 +404,26 @@ public class OpendaylightToaster implements ToasterService, ToasterProviderRunti notificationProvider.publish( new ToasterOutOfBreadBuilder().build() ); } - synchronized (taskLock) { - currentTask = null; - } + // Set the Toaster status back to up - this essentially releases the toasting lock. + // We can't clear the current toast task nor set the Future result until the + // update has been committed so we pass a callback to be notified on completion. + + setToasterStatusUp( new Function() { + @Override + public Void apply( Boolean result ) { + + currentMakeToastTask.set( null ); + + LOG.debug("Toast done"); - updateStatus(); + futureResult.set( Rpcs.getRpcResult( true, null, + Collections.emptyList() ) ); - LOG.debug("Toast done"); + return null; + } + } ); - return Rpcs. getRpcResult(true, null, Collections. emptySet()); + return null; } } }