package org.opendaylight.controller.cluster.datastore;
-import akka.actor.ActorSelection;
-import akka.dispatch.OnComplete;
-import java.util.AbstractMap.SimpleEntry;
+import com.google.common.base.Preconditions;
+import java.util.Collections;
import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
+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 scala.concurrent.Future;
-import scala.concurrent.Promise;
/**
* TransactionChainProxy acts as a proxy for a DOMStoreTransactionChain created on a remote shard
*/
-public class TransactionChainProxy implements DOMStoreTransactionChain{
+public class TransactionChainProxy implements DOMStoreTransactionChain {
+
+ private interface State {
+ boolean isReady();
+
+ List<Future<Object>> getPreviousReadyFutures();
+ }
+
+ private static class Allocated implements State {
+ private final ChainedTransactionProxy transaction;
+
+ Allocated(ChainedTransactionProxy transaction) {
+ this.transaction = transaction;
+ }
+
+ @Override
+ public boolean isReady() {
+ return transaction.isReady();
+ }
+
+ @Override
+ public List<Future<Object>> getPreviousReadyFutures() {
+ return transaction.getReadyFutures();
+ }
+ }
+
+ private static abstract class AbstractDefaultState implements State {
+ @Override
+ public List<Future<Object>> getPreviousReadyFutures() {
+ return Collections.emptyList();
+ }
+ }
+
+ private static final State IDLE_STATE = new AbstractDefaultState() {
+ @Override
+ public boolean isReady() {
+ return true;
+ }
+ };
+
+ private static final State CLOSED_STATE = new AbstractDefaultState() {
+ @Override
+ public boolean isReady() {
+ throw new TransactionChainClosedException("Transaction chain has been closed");
+ }
+ };
+
+ private static final AtomicInteger counter = new AtomicInteger(0);
+
private final ActorContext actorContext;
private final String transactionChainId;
- private volatile SimpleEntry<Object, List<Future<ActorSelection>>> previousTxReadyFutures;
+ private volatile State currentState = IDLE_STATE;
public TransactionChainProxy(ActorContext actorContext) {
this.actorContext = actorContext;
- transactionChainId = actorContext.getCurrentMemberName() + "-" + System.currentTimeMillis();
+ transactionChainId = actorContext.getCurrentMemberName() + "-txn-chain-" + counter.incrementAndGet();
+ }
+
+ public String getTransactionChainId() {
+ return transactionChainId;
}
@Override
public DOMStoreReadTransaction newReadOnlyTransaction() {
- return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.READ_ONLY);
+ State localState = currentState;
+ checkReadyState(localState);
+
+ return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.READ_ONLY,
+ transactionChainId, localState.getPreviousReadyFutures());
}
@Override
public DOMStoreReadWriteTransaction newReadWriteTransaction() {
- return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.READ_WRITE);
+ actorContext.acquireTxCreationPermit();
+ return allocateWriteTransaction(TransactionProxy.TransactionType.READ_WRITE);
}
@Override
public DOMStoreWriteTransaction newWriteOnlyTransaction() {
- return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.WRITE_ONLY);
+ actorContext.acquireTxCreationPermit();
+ return allocateWriteTransaction(TransactionProxy.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));
+ actorContext.broadcast(new CloseTransactionChain(transactionChainId).toSerializable());
}
- public String getTransactionChainId() {
- return transactionChainId;
- }
+ private ChainedTransactionProxy allocateWriteTransaction(TransactionProxy.TransactionType type) {
+ State localState = currentState;
- private class ChainedTransactionProxy extends TransactionProxy {
+ checkReadyState(localState);
- ChainedTransactionProxy(ActorContext actorContext, TransactionType transactionType) {
- super(actorContext, transactionType, transactionChainId);
- }
+ // Pass the ready Futures from the previous Tx.
+ ChainedTransactionProxy txProxy = new ChainedTransactionProxy(actorContext, type,
+ transactionChainId, localState.getPreviousReadyFutures());
- @Override
- protected void onTransactionReady(List<Future<ActorSelection>> cohortFutures) {
- if(!cohortFutures.isEmpty()) {
- previousTxReadyFutures = new SimpleEntry<>(getIdentifier(), cohortFutures);
- } else {
- previousTxReadyFutures = null;
- }
- }
+ currentState = new Allocated(txProxy);
- /**
- * 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);
- }
-
- // 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));
- }
- }
- };
-
- combinedFutures.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
-
- return createTxPromise.future();
- }
+ return txProxy;
+ }
+
+ private void checkReadyState(State state) {
+ Preconditions.checkState(state.isReady(), "Previous transaction is not ready yet");
}
}
Code Review / controller.git / blobdiff