import akka.dispatch.OnComplete;
import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.FinalizablePhantomReference;
+import com.google.common.base.FinalizableReferenceQueue;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
/**
LOG = LoggerFactory.getLogger(TransactionProxy.class);
+ /**
+ * Used to enqueue the PhantomReferences for read-only TransactionProxy instances. The
+ * FinalizableReferenceQueue is safe to use statically in an OSGi environment as it uses some
+ * trickery to clean up its internal thread when the bundle is unloaded.
+ */
+ private static final FinalizableReferenceQueue phantomReferenceQueue =
+ new FinalizableReferenceQueue();
+
+ /**
+ * This stores the TransactionProxyCleanupPhantomReference instances statically, This is
+ * necessary because PhantomReferences need a hard reference so they're not garbage collected.
+ * Once finalized, the TransactionProxyCleanupPhantomReference removes itself from this map
+ * and thus becomes eligible for garbage collection.
+ */
+ private static final Map<TransactionProxyCleanupPhantomReference,
+ TransactionProxyCleanupPhantomReference> phantomReferenceCache =
+ new ConcurrentHashMap<>();
+
+ /**
+ * A PhantomReference that closes remote transactions for a TransactionProxy when it's
+ * garbage collected. This is used for read-only transactions as they're not explicitly closed
+ * by clients. So the only way to detect that a transaction is no longer in use and it's safe
+ * to clean up is when it's garbage collected. It's inexact as to when an instance will be GC'ed
+ * but TransactionProxy instances should generally be short-lived enough to avoid being moved
+ * to the old generation space and thus should be cleaned up in a timely manner as the GC
+ * runs on the young generation (eden, swap1...) space much more frequently.
+ */
+ private static class TransactionProxyCleanupPhantomReference
+ extends FinalizablePhantomReference<TransactionProxy> {
+
+ private final List<ActorSelection> remoteTransactionActors;
+ private final AtomicBoolean remoteTransactionActorsMB;
+ private final ActorContext actorContext;
+ private final TransactionIdentifier identifier;
+
+ protected TransactionProxyCleanupPhantomReference(TransactionProxy referent) {
+ super(referent, phantomReferenceQueue);
+
+ // Note we need to cache the relevant fields from the TransactionProxy as we can't
+ // have a hard reference to the TransactionProxy instance itself.
+
+ remoteTransactionActors = referent.remoteTransactionActors;
+ remoteTransactionActorsMB = referent.remoteTransactionActorsMB;
+ actorContext = referent.actorContext;
+ identifier = referent.identifier;
+ }
+
+ @Override
+ public void finalizeReferent() {
+ LOG.trace("Cleaning up {} Tx actors for TransactionProxy {}",
+ remoteTransactionActors.size(), identifier);
+
+ phantomReferenceCache.remove(this);
+
+ // Access the memory barrier volatile to ensure all previous updates to the
+ // remoteTransactionActors list are visible to this thread.
+
+ if(remoteTransactionActorsMB.get()) {
+ for(ActorSelection actor : remoteTransactionActors) {
+ LOG.trace("Sending CloseTransaction to {}", actor);
+ actorContext.sendRemoteOperationAsync(actor,
+ new CloseTransaction().toSerializable());
+ }
+ }
+ }
+ }
+
+ /**
+ * Stores the remote Tx actors for each requested data store path to be used by the
+ * PhantomReference to close the remote Tx's. This is only used for read-only Tx's. The
+ * remoteTransactionActorsMB volatile serves as a memory barrier to publish updates to the
+ * remoteTransactionActors list so they will be visible to the thread accessing the
+ * PhantomReference.
+ */
+ private List<ActorSelection> remoteTransactionActors;
+ private AtomicBoolean remoteTransactionActorsMB;
+
+ private final Map<String, TransactionContext> remoteTransactionPaths = new HashMap<>();
+
private final TransactionType transactionType;
private final ActorContext actorContext;
- private final Map<String, TransactionContext> remoteTransactionPaths = new HashMap<>();
private final TransactionIdentifier identifier;
private final SchemaContext schemaContext;
private boolean inReadyState;
- public TransactionProxy(ActorContext actorContext, TransactionType transactionType,
- SchemaContext schemaContext) {
- this.actorContext = Preconditions.checkNotNull(actorContext, "actorContext should not be null");
- this.transactionType = Preconditions.checkNotNull(transactionType, "transactionType should not be null");
- this.schemaContext = Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
+ public TransactionProxy(ActorContext actorContext, TransactionType transactionType) {
+ this.actorContext = Preconditions.checkNotNull(actorContext,
+ "actorContext should not be null");
+ this.transactionType = Preconditions.checkNotNull(transactionType,
+ "transactionType should not be null");
+ this.schemaContext = Preconditions.checkNotNull(actorContext.getSchemaContext(),
+ "schemaContext should not be null");
String memberName = actorContext.getCurrentMemberName();
if(memberName == null){
this.identifier = TransactionIdentifier.builder().memberName(memberName).counter(
counter.getAndIncrement()).build();
- LOG.debug("Created txn {} of type {}", identifier, transactionType);
+ if(transactionType == TransactionType.READ_ONLY) {
+ // Read-only Tx's aren't explicitly closed by the client so we create a PhantomReference
+ // to close the remote Tx's when this instance is no longer in use and is garbage
+ // collected.
+ remoteTransactionActors = Lists.newArrayList();
+ remoteTransactionActorsMB = new AtomicBoolean();
+
+ TransactionProxyCleanupPhantomReference cleanup =
+ new TransactionProxyCleanupPhantomReference(this);
+ phantomReferenceCache.put(cleanup, cleanup);
+ }
+
+ LOG.debug("Created txn {} of type {}", identifier, transactionType);
}
@VisibleForTesting
Preconditions.checkState(transactionType != TransactionType.READ_ONLY,
"Modification operation on read-only transaction is not allowed");
Preconditions.checkState(!inReadyState,
- "Transaction is sealed - further modifications are allowed");
+ "Transaction is sealed - further modifications are not allowed");
}
@Override
for(TransactionContext transactionContext : remoteTransactionPaths.values()) {
transactionContext.closeTransaction();
}
+
+ remoteTransactionPaths.clear();
+
+ if(transactionType == TransactionType.READ_ONLY) {
+ remoteTransactionActors.clear();
+ remoteTransactionActorsMB.set(true);
+ }
}
private TransactionContext transactionContext(YangInstanceIdentifier path){
try {
Object response = actorContext.executeShardOperation(shardName,
- new CreateTransaction(identifier.toString(),this.transactionType.ordinal() ).toSerializable(),
- ActorContext.ASK_DURATION);
+ new CreateTransaction(identifier.toString(),this.transactionType.ordinal() ).toSerializable());
if (response.getClass().equals(CreateTransactionReply.SERIALIZABLE_CLASS)) {
CreateTransactionReply reply =
CreateTransactionReply.fromSerializable(response);
LOG.debug("Tx {} Received transaction path = {}", identifier, transactionPath);
- ActorSelection transactionActor =
- actorContext.actorSelection(transactionPath);
- transactionContext =
- new TransactionContextImpl(shardName, transactionPath,
- transactionActor);
+ ActorSelection transactionActor = actorContext.actorSelection(transactionPath);
+
+ if(transactionType == TransactionType.READ_ONLY) {
+ // Add the actor to the remoteTransactionActors list for access by the
+ // cleanup PhantonReference.
+ remoteTransactionActors.add(transactionActor);
+
+ // Write to the memory barrier volatile to publish the above update to the
+ // remoteTransactionActors list for thread visibility.
+ remoteTransactionActorsMB.set(true);
+ }
+
+ transactionContext = new TransactionContextImpl(shardName, transactionPath,
+ transactionActor, identifier, actorContext, schemaContext);
remoteTransactionPaths.put(shardName, transactionContext);
} else {
}
} catch(Exception e){
LOG.debug("Tx {} Creating NoOpTransaction because of : {}", identifier, e.getMessage());
- remoteTransactionPaths.put(shardName, new NoOpTransactionContext(shardName, e));
+ remoteTransactionPaths.put(shardName, new NoOpTransactionContext(shardName, e, identifier));
}
}
List<Future<Object>> getRecordedOperationFutures();
}
- private abstract class AbstractTransactionContext implements TransactionContext {
+ private static abstract class AbstractTransactionContext implements TransactionContext {
+ protected final TransactionIdentifier identifier;
protected final String shardName;
protected final List<Future<Object>> recordedOperationFutures = Lists.newArrayList();
- AbstractTransactionContext(String shardName) {
+ AbstractTransactionContext(String shardName, TransactionIdentifier identifier) {
this.shardName = shardName;
+ this.identifier = identifier;
}
@Override
}
}
- private class TransactionContextImpl extends AbstractTransactionContext {
+ private static class TransactionContextImpl extends AbstractTransactionContext {
private final Logger LOG = LoggerFactory.getLogger(TransactionContextImpl.class);
+ private final ActorContext actorContext;
+ private final SchemaContext schemaContext;
private final String actorPath;
private final ActorSelection actor;
private TransactionContextImpl(String shardName, String actorPath,
- ActorSelection actor) {
- super(shardName);
+ ActorSelection actor, TransactionIdentifier identifier, ActorContext actorContext,
+ SchemaContext schemaContext) {
+ super(shardName, identifier);
this.actorPath = actorPath;
this.actor = actor;
+ this.actorContext = actorContext;
+ this.schemaContext = schemaContext;
}
private ActorSelection getActor() {
// Send the ReadyTransaction message to the Tx actor.
final Future<Object> replyFuture = actorContext.executeRemoteOperationAsync(getActor(),
- new ReadyTransaction().toSerializable(), ActorContext.ASK_DURATION);
+ new ReadyTransaction().toSerializable());
// Combine all the previously recorded put/merge/delete operation reply Futures and the
// ReadyTransactionReply Future into one Future. If any one fails then the combined
public void deleteData(YangInstanceIdentifier path) {
LOG.debug("Tx {} deleteData called path = {}", identifier, path);
recordedOperationFutures.add(actorContext.executeRemoteOperationAsync(getActor(),
- new DeleteData(path).toSerializable(), ActorContext.ASK_DURATION ));
+ new DeleteData(path).toSerializable() ));
}
@Override
public void mergeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
LOG.debug("Tx {} mergeData called path = {}", identifier, path);
recordedOperationFutures.add(actorContext.executeRemoteOperationAsync(getActor(),
- new MergeData(path, data, schemaContext).toSerializable(),
- ActorContext.ASK_DURATION));
+ new MergeData(path, data, schemaContext).toSerializable()));
}
@Override
public void writeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
LOG.debug("Tx {} writeData called path = {}", identifier, path);
recordedOperationFutures.add(actorContext.executeRemoteOperationAsync(getActor(),
- new WriteData(path, data, schemaContext).toSerializable(),
- ActorContext.ASK_DURATION));
+ new WriteData(path, data, schemaContext).toSerializable()));
}
@Override
returnFuture.setException(new ReadFailedException(
"Error reading data for path " + path, failure));
+
} else {
LOG.debug("Tx {} read operation succeeded", identifier, failure);
};
Future<Object> readFuture = actorContext.executeRemoteOperationAsync(getActor(),
- new ReadData(path).toSerializable(), ActorContext.ASK_DURATION);
+ new ReadData(path).toSerializable());
readFuture.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
}
};
Future<Object> future = actorContext.executeRemoteOperationAsync(getActor(),
- new DataExists(path).toSerializable(), ActorContext.ASK_DURATION);
+ new DataExists(path).toSerializable());
future.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
}
}
- private class NoOpTransactionContext extends AbstractTransactionContext {
+ private static class NoOpTransactionContext extends AbstractTransactionContext {
private final Logger LOG = LoggerFactory.getLogger(NoOpTransactionContext.class);
private final Exception failure;
- public NoOpTransactionContext(String shardName, Exception failure){
- super(shardName);
+ public NoOpTransactionContext(String shardName, Exception failure,
+ TransactionIdentifier identifier){
+ super(shardName, identifier);
this.failure = failure;
}
Code Review / controller.git / blobdiff