/*
- * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
+ * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
-
package org.opendaylight.controller.cluster.datastore;
import akka.actor.ActorSelection;
import akka.dispatch.OnComplete;
-import java.util.AbstractMap.SimpleEntry;
-import java.util.List;
+import com.google.common.base.Preconditions;
+import java.util.Collection;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
+import org.opendaylight.controller.cluster.datastore.identifiers.TransactionChainIdentifier;
+import org.opendaylight.controller.cluster.datastore.identifiers.TransactionIdentifier;
import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
-import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
+import org.opendaylight.controller.cluster.datastore.messages.PrimaryShardInfo;
+import org.opendaylight.controller.md.sal.common.api.data.TransactionChainClosedException;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
import scala.concurrent.Future;
import scala.concurrent.Promise;
/**
- * TransactionChainProxy acts as a proxy for a DOMStoreTransactionChain created on a remote shard
+ * A chain of {@link TransactionProxy}s. It allows a single open transaction to be open
+ * at a time. For remote transactions, it also tracks the outstanding readiness requests
+ * towards the shard and unblocks operations only after all have completed.
*/
-public class TransactionChainProxy implements DOMStoreTransactionChain{
- private final ActorContext actorContext;
- private final String transactionChainId;
- private volatile SimpleEntry<Object, List<Future<ActorSelection>>> previousTxReadyFutures;
+final class TransactionChainProxy extends AbstractTransactionContextFactory<LocalTransactionChain> implements DOMStoreTransactionChain {
+ private static abstract class State {
+ /**
+ * Check if it is okay to allocate a new transaction.
+ * @throws IllegalStateException if a transaction may not be allocated.
+ */
+ abstract void checkReady();
+
+ /**
+ * Return the future which needs to be waited for before shard information
+ * is returned (which unblocks remote transactions).
+ * @return Future to wait for, or null of no wait is necessary
+ */
+ abstract Future<?> previousFuture();
+ }
+
+ private static abstract class Pending extends State {
+ private final TransactionIdentifier transaction;
+ private final Future<?> previousFuture;
+
+ Pending(final TransactionIdentifier transaction, final Future<?> previousFuture) {
+ this.previousFuture = previousFuture;
+ this.transaction = Preconditions.checkNotNull(transaction);
+ }
+
+ @Override
+ final Future<?> previousFuture() {
+ return previousFuture;
+ }
+
+ final TransactionIdentifier getIdentifier() {
+ return transaction;
+ }
+ }
+
+ private static final class Allocated extends Pending {
+ Allocated(final TransactionIdentifier transaction, final Future<?> previousFuture) {
+ super(transaction, previousFuture);
+ }
+
+ @Override
+ void checkReady() {
+ throw new IllegalStateException(String.format("Previous transaction %s is not ready yet", getIdentifier()));
+ }
+ }
+
+ private static final class Submitted extends Pending {
+ Submitted(final TransactionIdentifier transaction, final Future<?> previousFuture) {
+ super(transaction, previousFuture);
+ }
+
+ @Override
+ void checkReady() {
+ // Okay to allocate
+ }
+ }
+
+ private static abstract class DefaultState extends State {
+ @Override
+ final Future<?> previousFuture() {
+ return null;
+ }
+ }
+
+ private static final State IDLE_STATE = new DefaultState() {
+ @Override
+ void checkReady() {
+ // Okay to allocate
+ }
+ };
- public TransactionChainProxy(ActorContext actorContext) {
- this.actorContext = actorContext;
- transactionChainId = actorContext.getCurrentMemberName() + "-" + System.currentTimeMillis();
+ private static final State CLOSED_STATE = new DefaultState() {
+ @Override
+ void checkReady() {
+ throw new TransactionChainClosedException("Transaction chain has been closed");
+ }
+ };
+
+ private static final Logger LOG = LoggerFactory.getLogger(TransactionChainProxy.class);
+ private static final AtomicInteger CHAIN_COUNTER = new AtomicInteger();
+ private static final AtomicReferenceFieldUpdater<TransactionChainProxy, State> STATE_UPDATER =
+ AtomicReferenceFieldUpdater.newUpdater(TransactionChainProxy.class, State.class, "currentState");
+
+ private final TransactionChainIdentifier transactionChainId;
+ private final TransactionContextFactory parent;
+ private volatile State currentState = IDLE_STATE;
+
+ TransactionChainProxy(final TransactionContextFactory parent) {
+ super(parent.getActorContext());
+
+ transactionChainId = new TransactionChainIdentifier(parent.getActorContext().getCurrentMemberName(), CHAIN_COUNTER.incrementAndGet());
+ this.parent = parent;
+ }
+
+ public String getTransactionChainId() {
+ return transactionChainId.toString();
}
@Override
public DOMStoreReadTransaction newReadOnlyTransaction() {
- return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.READ_ONLY);
+ currentState.checkReady();
+ return new TransactionProxy(this, TransactionType.READ_ONLY);
}
@Override
public DOMStoreReadWriteTransaction newReadWriteTransaction() {
- return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.READ_WRITE);
+ getActorContext().acquireTxCreationPermit();
+ return allocateWriteTransaction(TransactionType.READ_WRITE);
}
@Override
public DOMStoreWriteTransaction newWriteOnlyTransaction() {
- return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.WRITE_ONLY);
+ getActorContext().acquireTxCreationPermit();
+ return allocateWriteTransaction(TransactionType.WRITE_ONLY);
}
@Override
public void close() {
+ currentState = CLOSED_STATE;
+
// Send a close transaction chain request to each and every shard
- actorContext.broadcast(new CloseTransactionChain(transactionChainId));
+ getActorContext().broadcast(new CloseTransactionChain(transactionChainId.toString()).toSerializable());
}
- public String getTransactionChainId() {
- return transactionChainId;
+ private TransactionProxy allocateWriteTransaction(final TransactionType type) {
+ State localState = currentState;
+ localState.checkReady();
+
+ final TransactionProxy ret = new TransactionProxy(this, type);
+ currentState = new Allocated(ret.getIdentifier(), localState.previousFuture());
+ return ret;
}
- private class ChainedTransactionProxy extends TransactionProxy {
+ @Override
+ protected LocalTransactionChain factoryForShard(final String shardName, final ActorSelection shardLeader, final DataTree dataTree) {
+ final LocalTransactionChain ret = new LocalTransactionChain(this, shardLeader, dataTree);
+ LOG.debug("Allocated transaction chain {} for shard {} leader {}", ret, shardName, shardLeader);
+ return ret;
+ }
- ChainedTransactionProxy(ActorContext actorContext, TransactionType transactionType) {
- super(actorContext, transactionType, transactionChainId);
+ /**
+ * This method is overridden to ensure the previous Tx's ready operations complete
+ * before we initiate the next Tx in the chain to avoid creation failures if the
+ * previous Tx's ready operations haven't completed yet.
+ */
+ @Override
+ protected Future<PrimaryShardInfo> findPrimaryShard(final String shardName) {
+ // Read current state atomically
+ final State localState = currentState;
+
+ // There are no outstanding futures, shortcut
+ final Future<?> previous = localState.previousFuture();
+ if (previous == null) {
+ return parent.findPrimaryShard(shardName);
}
- @Override
- protected void onTransactionReady(List<Future<ActorSelection>> cohortFutures) {
- if(!cohortFutures.isEmpty()) {
- previousTxReadyFutures = new SimpleEntry<>(getIdentifier(), cohortFutures);
- } else {
- previousTxReadyFutures = null;
- }
+ final String previousTransactionId;
+
+ if(localState instanceof Pending){
+ previousTransactionId = ((Pending) localState).getIdentifier().toString();
+ LOG.debug("Waiting for ready futures with pending Tx {}", previousTransactionId);
+ } else {
+ previousTransactionId = "";
+ LOG.debug("Waiting for ready futures on chain {}", getTransactionChainId());
}
- /**
- * This method is overridden to ensure the previous Tx's ready operations complete
- * before we create the next shard Tx in the chain to avoid creation failures if the
- * previous Tx's ready operations haven't completed yet.
- */
- @Override
- protected Future<Object> sendCreateTransaction(final ActorSelection shard,
- final Object serializedCreateMessage) {
- // Check if there are any previous ready Futures. Also make sure the previous ready
- // Futures aren't for this Tx as deadlock would occur if tried to wait on our own
- // Futures. This may happen b/c the shard Tx creates are done async so it's possible
- // for the client to ready this Tx before we've even attempted to create a shard Tx.
- if(previousTxReadyFutures == null ||
- previousTxReadyFutures.getKey().equals(getIdentifier())) {
- return super.sendCreateTransaction(shard, serializedCreateMessage);
- }
+ // Add a callback for completion of the combined Futures.
+ final Promise<PrimaryShardInfo> returnPromise = akka.dispatch.Futures.promise();
- // Combine the ready Futures into 1.
- Future<Iterable<ActorSelection>> combinedFutures = akka.dispatch.Futures.sequence(
- previousTxReadyFutures.getValue(), actorContext.getActorSystem().dispatcher());
-
- // Add a callback for completion of the combined Futures.
- final Promise<Object> createTxPromise = akka.dispatch.Futures.promise();
- OnComplete<Iterable<ActorSelection>> onComplete = new OnComplete<Iterable<ActorSelection>>() {
- @Override
- public void onComplete(Throwable failure, Iterable<ActorSelection> notUsed) {
- if(failure != null) {
- // A Ready Future failed so fail the returned Promise.
- createTxPromise.failure(failure);
- } else {
- // Send the CreateTx message and use the resulting Future to complete the
- // returned Promise.
- createTxPromise.completeWith(actorContext.executeOperationAsync(shard,
- serializedCreateMessage));
- }
+ final OnComplete onComplete = new OnComplete() {
+ @Override
+ public void onComplete(final Throwable failure, final Object notUsed) {
+ if (failure != null) {
+ // A Ready Future failed so fail the returned Promise.
+ LOG.error("Ready future failed for Tx {}", previousTransactionId);
+ returnPromise.failure(failure);
+ } else {
+ LOG.debug("Previous Tx {} readied - proceeding to FindPrimaryShard",
+ previousTransactionId);
+
+ // Send the FindPrimaryShard message and use the resulting Future to complete the
+ // returned Promise.
+ returnPromise.completeWith(parent.findPrimaryShard(shardName));
}
- };
+ }
+ };
- combinedFutures.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+ previous.onComplete(onComplete, getActorContext().getClientDispatcher());
+ return returnPromise.future();
+ }
- return createTxPromise.future();
+ @Override
+ protected <T> void onTransactionReady(final TransactionIdentifier transaction, final Collection<Future<T>> cohortFutures) {
+ final State localState = currentState;
+ Preconditions.checkState(localState instanceof Allocated, "Readying transaction %s while state is %s", transaction, localState);
+ final TransactionIdentifier currentTx = ((Allocated)localState).getIdentifier();
+ Preconditions.checkState(transaction.equals(currentTx), "Readying transaction %s while %s is allocated", transaction, currentTx);
+
+ // Transaction ready and we are not waiting for futures -- go to idle
+ if (cohortFutures.isEmpty()) {
+ currentState = IDLE_STATE;
+ return;
}
+
+ // Combine the ready Futures into 1
+ final Future<Iterable<T>> combined = akka.dispatch.Futures.sequence(
+ cohortFutures, getActorContext().getClientDispatcher());
+
+ // Record the we have outstanding futures
+ final State newState = new Submitted(transaction, combined);
+ currentState = newState;
+
+ // Attach a completion reset, but only if we do not allocate a transaction
+ // in-between
+ combined.onComplete(new OnComplete<Iterable<T>>() {
+ @Override
+ public void onComplete(final Throwable arg0, final Iterable<T> arg1) {
+ STATE_UPDATER.compareAndSet(TransactionChainProxy.this, newState, IDLE_STATE);
+ }
+ }, getActorContext().getClientDispatcher());
+ }
+
+ @Override
+ protected TransactionIdentifier nextIdentifier() {
+ return transactionChainId.newTransactionIdentifier();
}
}
Code Review / controller.git / blobdiff