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.ArrayList;
import java.util.Collection;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
+import java.util.function.Function;
+import javax.annotation.Nonnull;
+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.messages.PrimaryShardInfo;
private static final AtomicReferenceFieldUpdater<TransactionChainProxy, State> STATE_UPDATER =
AtomicReferenceFieldUpdater.newUpdater(TransactionChainProxy.class, State.class, "currentState");
- private final String transactionChainId;
+ private final TransactionChainIdentifier transactionChainId;
private final TransactionContextFactory parent;
private volatile State currentState = IDLE_STATE;
+ /**
+ * 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) {
super(parent.getActorContext());
- transactionChainId = parent.getActorContext().getCurrentMemberName() + "-txn-chain-" + CHAIN_COUNTER.incrementAndGet();
+
+ transactionChainId = new TransactionChainIdentifier(parent.getActorContext().getCurrentMemberName(), CHAIN_COUNTER.incrementAndGet());
this.parent = parent;
}
public String getTransactionChainId() {
- return transactionChainId;
+ return transactionChainId.toString();
}
@Override
public DOMStoreReadTransaction newReadOnlyTransaction() {
currentState.checkReady();
- return new TransactionProxy(this, TransactionType.READ_ONLY);
+ TransactionProxy transactionProxy = new TransactionProxy(this, TransactionType.READ_ONLY);
+ priorReadOnlyTxPromises.put(transactionProxy.getIdentifier(), Futures.<Object>promise());
+ return transactionProxy;
}
@Override
currentState = CLOSED_STATE;
// Send a close transaction chain request to each and every shard
- getActorContext().broadcast(new CloseTransactionChain(transactionChainId).toSerializable());
- parent.removeTransactionChain(this);
+
+ getActorContext().broadcast(new Function<Short, Object>() {
+ @Override
+ public Object apply(Short version) {
+ return new CloseTransactionChain(transactionChainId.toString(), version).toSerializable();
+ }
+ });
}
private TransactionProxy allocateWriteTransaction(final TransactionType type) {
return ret;
}
- @Override
- protected DataTree dataTreeForFactory(final LocalTransactionChain factory) {
- return factory.getDataTree();
- }
-
/**
* 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) {
+ protected Future<PrimaryShardInfo> findPrimaryShard(final String shardName, final TransactionIdentifier txId) {
// Read current state atomically
final State localState = currentState;
// There are no outstanding futures, shortcut
- final Future<?> previous = localState.previousFuture();
+ Future<?> previous = localState.previousFuture();
if (previous == null) {
- return parent.findPrimaryShard(shardName);
+ return combineFutureWithPossiblePriorReadOnlyTxFutures(parent.findPrimaryShard(shardName, txId), txId);
}
- LOG.debug("Waiting for ready futures for on chain {}", getTransactionChainId());
+ final String previousTransactionId;
+
+ 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());
+ }
+
+ previous = combineFutureWithPossiblePriorReadOnlyTxFutures(previous, txId);
// Add a callback for completion of the combined Futures.
- final Promise<PrimaryShardInfo> returnPromise = akka.dispatch.Futures.promise();
+ 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("Previous Tx readied - proceeding to FindPrimaryShard on chain {}",
- getTransactionChainId());
+ 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));
+ returnPromise.completeWith(parent.findPrimaryShard(shardName, txId));
}
}
};
return returnPromise.future();
}
+ 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;
+ }
+
+ 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());
+
+ final Promise<T> returnPromise = Futures.promise();
+ final OnComplete<Iterable<Object>> onComplete = new OnComplete<Iterable<Object>>() {
+ @Override
+ 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().getClientDispatcher());
+ return returnPromise.future();
+ } else {
+ return future;
+ }
+ }
+
@Override
protected <T> void onTransactionReady(final TransactionIdentifier transaction, final Collection<Future<T>> cohortFutures) {
final State localState = currentState;
}
// Combine the ready Futures into 1
- final Future<Iterable<T>> combined = akka.dispatch.Futures.sequence(
- cohortFutures, getActorContext().getClientDispatcher());
+ final Future<Iterable<T>> combined = Futures.sequence(cohortFutures, getActorContext().getClientDispatcher());
// Record the we have outstanding futures
final State newState = new Submitted(transaction, combined);
}, getActorContext().getClientDispatcher());
}
+ @Override
+ protected void onTransactionContextCreated(@Nonnull TransactionIdentifier transactionId) {
+ Promise<Object> promise = priorReadOnlyTxPromises.remove(transactionId);
+ if(promise != null) {
+ promise.success(null);
+ }
+ }
+
@Override
protected TransactionIdentifier nextIdentifier() {
- return TransactionIdentifier.create(getMemberName(), TX_COUNTER.getAndIncrement(), transactionChainId);
+ return transactionChainId.newTransactionIdentifier();
}
}