/*
- * 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.Futures;
import akka.dispatch.OnComplete;
import com.google.common.base.Preconditions;
-import java.util.Collections;
+import java.util.ArrayList;
+import java.util.Collection;
import java.util.List;
-import java.util.concurrent.atomic.AtomicInteger;
+import java.util.Map.Entry;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
+import java.util.function.Function;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
+import org.opendaylight.controller.cluster.access.concepts.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 {
+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();
- private static final Logger LOG = LoggerFactory.getLogger(TransactionChainProxy.class);
+ /**
+ * 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 interface State {
- boolean isReady();
+ private static abstract class Pending extends State {
+ private final TransactionIdentifier transaction;
+ private final Future<?> previousFuture;
- List<Future<ActorSelection>> getPreviousReadyFutures();
- }
+ Pending(final TransactionIdentifier transaction, final Future<?> previousFuture) {
+ this.previousFuture = previousFuture;
+ this.transaction = Preconditions.checkNotNull(transaction);
+ }
- private static class Allocated implements State {
- private final ChainedTransactionProxy transaction;
+ @Override
+ final Future<?> previousFuture() {
+ return previousFuture;
+ }
- Allocated(ChainedTransactionProxy transaction) {
- this.transaction = transaction;
+ final TransactionIdentifier getIdentifier() {
+ return transaction;
+ }
+ }
+
+ private static final class Allocated extends Pending {
+ Allocated(final TransactionIdentifier transaction, final Future<?> previousFuture) {
+ super(transaction, previousFuture);
}
@Override
- public boolean isReady() {
- return transaction.isReady();
+ 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
- public List<Future<ActorSelection>> getPreviousReadyFutures() {
- return transaction.getReadyFutures();
+ void checkReady() {
+ // Okay to allocate
}
}
- private static abstract class AbstractDefaultState implements State {
+ private static abstract class DefaultState extends State {
@Override
- public List<Future<ActorSelection>> getPreviousReadyFutures() {
- return Collections.emptyList();
+ final Future<?> previousFuture() {
+ return null;
}
}
- private static final State IDLE_STATE = new AbstractDefaultState() {
+ private static final State IDLE_STATE = new DefaultState() {
@Override
- public boolean isReady() {
- return true;
+ void checkReady() {
+ // Okay to allocate
}
};
- private static final State CLOSED_STATE = new AbstractDefaultState() {
+ private static final State CLOSED_STATE = new DefaultState() {
@Override
- public boolean isReady() {
+ void checkReady() {
throw new TransactionChainClosedException("Transaction chain has been closed");
}
};
- private static final AtomicInteger counter = new AtomicInteger(0);
+ private static final Logger LOG = LoggerFactory.getLogger(TransactionChainProxy.class);
+ private static final AtomicReferenceFieldUpdater<TransactionChainProxy, State> STATE_UPDATER =
+ AtomicReferenceFieldUpdater.newUpdater(TransactionChainProxy.class, State.class, "currentState");
- private final ActorContext actorContext;
- private final String transactionChainId;
+ private final TransactionContextFactory parent;
private volatile State currentState = IDLE_STATE;
- public TransactionChainProxy(ActorContext actorContext) {
- this.actorContext = actorContext;
- transactionChainId = actorContext.getCurrentMemberName() + "-txn-chain-" + counter.incrementAndGet();
+ /**
+ * This map holds Promise instances for each read-only tx. It is used to maintain ordering of tx creates
+ * wrt to read-only tx's between this class and a LocalTransactionChain since they're bridged by
+ * asynchronous futures. Otherwise, in the following scenario, eg:
+ *
+ * 1) Create write tx1 on chain
+ * 2) do write and submit
+ * 3) Create read-only tx2 on chain and issue read
+ * 4) Create write tx3 on chain, do write but do not submit
+ *
+ * if the sequence/timing is right, tx3 may create its local tx on the LocalTransactionChain before tx2,
+ * which results in tx2 failing b/c tx3 isn't ready yet. So maintaining ordering prevents this issue
+ * (see Bug 4774).
+ * <p>
+ * A Promise is added via newReadOnlyTransaction. When the parent class completes the primary shard
+ * lookup and creates the TransactionContext (either success or failure), onTransactionContextCreated is
+ * called which completes the Promise. A write tx that is created prior to completion will wait on the
+ * Promise's Future via findPrimaryShard.
+ */
+ private final ConcurrentMap<TransactionIdentifier, Promise<Object>> priorReadOnlyTxPromises = new ConcurrentHashMap<>();
+
+ TransactionChainProxy(final TransactionContextFactory parent, final LocalHistoryIdentifier historyId) {
+ super(parent.getActorContext(), historyId);
+ this.parent = parent;
}
public String getTransactionChainId() {
- return transactionChainId;
+ return getHistoryId().toString();
}
@Override
public DOMStoreReadTransaction newReadOnlyTransaction() {
- State localState = currentState;
- checkReadyState(localState);
-
- return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.READ_ONLY,
- transactionChainId, localState.getPreviousReadyFutures());
+ currentState.checkReady();
+ TransactionProxy transactionProxy = new TransactionProxy(this, TransactionType.READ_ONLY);
+ priorReadOnlyTxPromises.put(transactionProxy.getIdentifier(), Futures.<Object>promise());
+ return transactionProxy;
}
@Override
public DOMStoreReadWriteTransaction newReadWriteTransaction() {
- return allocateWriteTransaction(TransactionProxy.TransactionType.READ_WRITE);
+ getActorContext().acquireTxCreationPermit();
+ return allocateWriteTransaction(TransactionType.READ_WRITE);
}
@Override
public DOMStoreWriteTransaction newWriteOnlyTransaction() {
- return allocateWriteTransaction(TransactionProxy.TransactionType.WRITE_ONLY);
+ getActorContext().acquireTxCreationPermit();
+ return allocateWriteTransaction(TransactionType.WRITE_ONLY);
}
@Override
currentState = CLOSED_STATE;
// Send a close transaction chain request to each and every shard
- actorContext.broadcast(new CloseTransactionChain(transactionChainId));
+
+ getActorContext().broadcast(new Function<Short, Object>() {
+ @Override
+ public Object apply(Short version) {
+ return new CloseTransactionChain(getHistoryId().toString(), version).toSerializable();
+ }
+ });
}
- private ChainedTransactionProxy allocateWriteTransaction(TransactionProxy.TransactionType type) {
+ private TransactionProxy allocateWriteTransaction(final TransactionType type) {
State localState = currentState;
+ localState.checkReady();
- checkReadyState(localState);
-
- // Pass the ready Futures from the previous Tx.
- ChainedTransactionProxy txProxy = new ChainedTransactionProxy(actorContext, type,
- transactionChainId, localState.getPreviousReadyFutures());
-
- currentState = new Allocated(txProxy);
-
- return txProxy;
+ final TransactionProxy ret = new TransactionProxy(this, type);
+ currentState = new Allocated(ret.getIdentifier(), localState.previousFuture());
+ return ret;
}
- private void checkReadyState(State state) {
- Preconditions.checkState(state.isReady(), "Previous transaction is not ready yet");
+ @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;
}
- private static class ChainedTransactionProxy extends TransactionProxy {
-
- /**
- * Stores the ready Futures from the previous Tx in the chain.
- */
- private final List<Future<ActorSelection>> previousReadyFutures;
-
- /**
- * Stores the ready Futures from this transaction when it is readied.
- */
- private volatile List<Future<ActorSelection>> readyFutures;
-
- private ChainedTransactionProxy(ActorContext actorContext, TransactionType transactionType,
- String transactionChainId, List<Future<ActorSelection>> previousReadyFutures) {
- super(actorContext, transactionType, transactionChainId);
- this.previousReadyFutures = previousReadyFutures;
+ /**
+ * 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.
+ */
+ @SuppressWarnings({ "unchecked", "rawtypes" })
+ @Override
+ protected Future<PrimaryShardInfo> findPrimaryShard(final String shardName, final TransactionIdentifier txId) {
+ // Read current state atomically
+ final State localState = currentState;
+
+ // There are no outstanding futures, shortcut
+ Future<?> previous = localState.previousFuture();
+ if (previous == null) {
+ return combineFutureWithPossiblePriorReadOnlyTxFutures(parent.findPrimaryShard(shardName, txId), txId);
}
- List<Future<ActorSelection>> getReadyFutures() {
- return readyFutures;
- }
+ final String previousTransactionId;
- boolean isReady() {
- return readyFutures != null;
+ if(localState instanceof Pending){
+ previousTransactionId = ((Pending) localState).getIdentifier().toString();
+ LOG.debug("Tx: {} - waiting for ready futures with pending Tx {}", txId, previousTransactionId);
+ } else {
+ previousTransactionId = "";
+ LOG.debug("Waiting for ready futures on chain {}", getTransactionChainId());
}
- @Override
- protected void onTransactionReady(List<Future<ActorSelection>> readyFutures) {
- LOG.debug("onTransactionReady {} pending readyFutures size {} chain {}", getIdentifier(),
- readyFutures.size(), getTransactionChainId());
- this.readyFutures = readyFutures;
- }
+ previous = combineFutureWithPossiblePriorReadOnlyTxFutures(previous, txId);
+
+ // Add a callback for completion of the combined Futures.
+ final Promise<PrimaryShardInfo> returnPromise = Futures.promise();
+
+ 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("Tx: {} - ready future failed for previous Tx {}", txId, previousTransactionId);
+ returnPromise.failure(failure);
+ } else {
+ LOG.debug("Tx: {} - previous Tx {} readied - proceeding to FindPrimaryShard",
+ txId, previousTransactionId);
+
+ // Send the FindPrimaryShard message and use the resulting Future to complete the
+ // returned Promise.
+ returnPromise.completeWith(parent.findPrimaryShard(shardName, txId));
+ }
+ }
+ };
- /**
- * 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) {
+ previous.onComplete(onComplete, getActorContext().getClientDispatcher());
+ return returnPromise.future();
+ }
- // Check if there are any previous ready Futures, otherwise let the super class handle it.
- if(previousReadyFutures.isEmpty()) {
- return super.sendCreateTransaction(shard, serializedCreateMessage);
+ private <T> Future<T> combineFutureWithPossiblePriorReadOnlyTxFutures(final Future<T> future,
+ final TransactionIdentifier txId) {
+ if(!priorReadOnlyTxPromises.containsKey(txId) && !priorReadOnlyTxPromises.isEmpty()) {
+ Collection<Entry<TransactionIdentifier, Promise<Object>>> priorReadOnlyTxPromiseEntries =
+ new ArrayList<>(priorReadOnlyTxPromises.entrySet());
+ if(priorReadOnlyTxPromiseEntries.isEmpty()) {
+ return future;
}
- // Combine the ready Futures into 1.
- Future<Iterable<ActorSelection>> combinedFutures = akka.dispatch.Futures.sequence(
- previousReadyFutures, getActorContext().getActorSystem().dispatcher());
+ List<Future<Object>> priorReadOnlyTxFutures = new ArrayList<>(priorReadOnlyTxPromiseEntries.size());
+ for(Entry<TransactionIdentifier, Promise<Object>> entry: priorReadOnlyTxPromiseEntries) {
+ LOG.debug("Tx: {} - waiting on future for prior read-only Tx {}", txId, entry.getKey());
+ priorReadOnlyTxFutures.add(entry.getValue().future());
+ }
+
+ Future<Iterable<Object>> combinedFutures = Futures.sequence(priorReadOnlyTxFutures,
+ getActorContext().getClientDispatcher());
- // 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>>() {
+ final Promise<T> returnPromise = Futures.promise();
+ final OnComplete<Iterable<Object>> onComplete = new OnComplete<Iterable<Object>>() {
@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 {
- LOG.debug("Previous Tx readied - sending CreateTransaction for {} on chain {}",
- getIdentifier(), getTransactionChainId());
-
- // Send the CreateTx message and use the resulting Future to complete the
- // returned Promise.
- createTxPromise.completeWith(getActorContext().executeOperationAsync(shard,
- serializedCreateMessage));
- }
+ public void onComplete(final Throwable failure, final Iterable<Object> notUsed) {
+ LOG.debug("Tx: {} - prior read-only Tx futures complete", txId);
+
+ // Complete the returned Promise with the original Future.
+ returnPromise.completeWith(future);
}
};
- combinedFutures.onComplete(onComplete, getActorContext().getActorSystem().dispatcher());
+ combinedFutures.onComplete(onComplete, getActorContext().getClientDispatcher());
+ return returnPromise.future();
+ } else {
+ return 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 = Futures.sequence(cohortFutures, getActorContext().getClientDispatcher());
- return createTxPromise.future();
+ // 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 void onTransactionContextCreated(@Nonnull TransactionIdentifier transactionId) {
+ Promise<Object> promise = priorReadOnlyTxPromises.remove(transactionId);
+ if(promise != null) {
+ promise.success(null);
}
}
}
Code Review / controller.git / blobdiff