import com.google.common.util.concurrent.CheckedFuture;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.MoreExecutors;
import com.google.common.util.concurrent.SettableFuture;
import java.util.ArrayList;
import java.util.Collection;
-import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
+import java.util.TreeMap;
import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
import org.opendaylight.controller.cluster.datastore.messages.AbstractRead;
import org.opendaylight.controller.cluster.datastore.messages.DataExists;
import org.opendaylight.controller.cluster.datastore.modification.WriteModification;
import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
import org.opendaylight.controller.cluster.datastore.utils.NormalizedNodeAggregator;
-import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
-import org.opendaylight.controller.sal.core.spi.data.AbstractDOMStoreTransaction;
-import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
-import org.opendaylight.yangtools.util.concurrent.MappingCheckedFuture;
+import org.opendaylight.mdsal.common.api.MappingCheckedFuture;
+import org.opendaylight.mdsal.common.api.ReadFailedException;
+import org.opendaylight.mdsal.dom.spi.store.AbstractDOMStoreTransaction;
+import org.opendaylight.mdsal.dom.spi.store.DOMStoreReadWriteTransaction;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
private static final Logger LOG = LoggerFactory.getLogger(TransactionProxy.class);
- private final Map<String, TransactionContextWrapper> txContextWrappers = new HashMap<>();
+ // Global lock used for transactions spanning multiple shards - synchronizes sending of the ready messages
+ // for atomicity to avoid potential deadlock with concurrent transactions spanning the same shards as outlined
+ // in the following scenario:
+ //
+ // - Tx1 sends ready message to shard A
+ // - Tx2 sends ready message to shard A
+ // - Tx2 sends ready message to shard B
+ // - Tx1 sends ready message to shard B
+ //
+ // This scenario results in deadlock: after Tx1 canCommits to shard A, it can't proceed with shard B until Tx2
+ // completes as Tx2 was readied first on shard B. However Tx2 cannot make progress because it's waiting to canCommit
+ // on shard A which is blocked by Tx1.
+ //
+ // The global lock avoids this as it forces the ready messages to be sent in a predictable order:
+ //
+ // - Tx1 sends ready message to shard A
+ // - Tx1 sends ready message to shard B
+ // - Tx2 sends ready message to shard A
+ // - Tx2 sends ready message to shard B
+ //
+ private static final Object GLOBAL_TX_READY_LOCK = new Object();
+
+ private final Map<String, TransactionContextWrapper> txContextWrappers = new TreeMap<>();
private final AbstractTransactionContextFactory<?> txContextFactory;
private final TransactionType type;
private TransactionState state = TransactionState.OPEN;
return executeRead(shardNameFromIdentifier(path), new DataExists(path, DataStoreVersions.CURRENT_VERSION));
}
- private <T> CheckedFuture<T, ReadFailedException> executeRead(String shardName, final AbstractRead<T> readCmd) {
+ private <T> CheckedFuture<T, ReadFailedException> executeRead(final String shardName,
+ final AbstractRead<T> readCmd) {
Preconditions.checkState(type != TransactionType.WRITE_ONLY,
"Reads from write-only transactions are not allowed");
- LOG.debug("Tx {} {} {}", getIdentifier(), readCmd.getClass().getSimpleName(), readCmd.getPath());
+ LOG.trace("Tx {} {} {}", getIdentifier(), readCmd.getClass().getSimpleName(), readCmd.getPath());
final SettableFuture<T> proxyFuture = SettableFuture.create();
TransactionContextWrapper contextWrapper = getContextWrapper(shardName);
contextWrapper.maybeExecuteTransactionOperation(new TransactionOperation() {
@Override
- public void invoke(TransactionContext transactionContext) {
- transactionContext.executeRead(readCmd, proxyFuture);
+ public void invoke(final TransactionContext transactionContext, final Boolean havePermit) {
+ transactionContext.executeRead(readCmd, proxyFuture, havePermit);
}
});
public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(final YangInstanceIdentifier path) {
Preconditions.checkState(type != TransactionType.WRITE_ONLY,
"Reads from write-only transactions are not allowed");
+ Preconditions.checkNotNull(path, "path should not be null");
- LOG.debug("Tx {} read {}", getIdentifier(), path);
-
- if (YangInstanceIdentifier.EMPTY.equals(path)) {
- return readAllData();
- } else {
- return singleShardRead(shardNameFromIdentifier(path), path);
- }
+ LOG.trace("Tx {} read {}", getIdentifier(), path);
+ return path.isEmpty() ? readAllData() : singleShardRead(shardNameFromIdentifier(path), path);
}
private CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> singleShardRead(
} catch (DataValidationFailedException e) {
throw new IllegalArgumentException("Failed to aggregate", e);
}
- });
+ }, MoreExecutors.directExecutor());
return MappingCheckedFuture.create(aggregateFuture, ReadFailedException.MAPPER);
}
private void executeModification(final AbstractModification modification) {
checkModificationState();
- LOG.debug("Tx {} executeModification {} {}", getIdentifier(), modification.getClass().getSimpleName(),
+ LOG.trace("Tx {} executeModification {} {}", getIdentifier(), modification.getClass().getSimpleName(),
modification.getPath());
TransactionContextWrapper contextWrapper = getContextWrapper(modification.getPath());
contextWrapper.maybeExecuteTransactionOperation(new TransactionOperation() {
@Override
- protected void invoke(TransactionContext transactionContext) {
- transactionContext.executeModification(modification);
+ protected void invoke(final TransactionContext transactionContext, final Boolean havePermit) {
+ transactionContext.executeModification(modification, havePermit);
}
});
}
for (TransactionContextWrapper contextWrapper : txContextWrappers.values()) {
contextWrapper.maybeExecuteTransactionOperation(new TransactionOperation() {
@Override
- public void invoke(TransactionContext transactionContext) {
+ public void invoke(final TransactionContext transactionContext, final Boolean havePermit) {
transactionContext.closeTransaction();
}
});
final Promise promise = akka.dispatch.Futures.promise();
contextWrapper.maybeExecuteTransactionOperation(new TransactionOperation() {
@Override
- public void invoke(TransactionContext newTransactionContext) {
- promise.completeWith(getDirectCommitFuture(newTransactionContext, operationCallbackRef));
+ public void invoke(final TransactionContext newTransactionContext, final Boolean havePermit) {
+ promise.completeWith(getDirectCommitFuture(newTransactionContext, operationCallbackRef,
+ havePermit));
}
});
future = promise.future();
} else {
// avoid the creation of a promise and a TransactionOperation
- future = getDirectCommitFuture(transactionContext, operationCallbackRef);
+ future = getDirectCommitFuture(transactionContext, operationCallbackRef, null);
}
return new SingleCommitCohortProxy(txContextFactory.getActorContext(), future, getIdentifier(),
operationCallbackRef);
}
- private Future<?> getDirectCommitFuture(TransactionContext transactionContext,
- OperationCallback.Reference operationCallbackRef) {
+ private Future<?> getDirectCommitFuture(final TransactionContext transactionContext,
+ final OperationCallback.Reference operationCallbackRef, final Boolean havePermit) {
TransactionRateLimitingCallback rateLimitingCallback = new TransactionRateLimitingCallback(
txContextFactory.getActorContext());
operationCallbackRef.set(rateLimitingCallback);
rateLimitingCallback.run();
- return transactionContext.directCommit();
+ return transactionContext.directCommit(havePermit);
}
private AbstractThreePhaseCommitCohort<ActorSelection> createMultiCommitCohort(
final Set<Entry<String, TransactionContextWrapper>> txContextWrapperEntries) {
final List<ThreePhaseCommitCohortProxy.CohortInfo> cohorts = new ArrayList<>(txContextWrapperEntries.size());
- for (Entry<String, TransactionContextWrapper> e : txContextWrapperEntries) {
- LOG.debug("Tx {} Readying transaction for shard {}", getIdentifier(), e.getKey());
- final TransactionContextWrapper wrapper = e.getValue();
+ synchronized (GLOBAL_TX_READY_LOCK) {
+ for (Entry<String, TransactionContextWrapper> e : txContextWrapperEntries) {
+ LOG.debug("Tx {} Readying transaction for shard {}", getIdentifier(), e.getKey());
+
+ final TransactionContextWrapper wrapper = e.getValue();
- // The remote tx version is obtained the via TransactionContext which may not be available yet so
- // we pass a Supplier to dynamically obtain it. Once the ready Future is resolved the
- // TransactionContext is available.
- Supplier<Short> txVersionSupplier = () -> wrapper.getTransactionContext().getTransactionVersion();
+ // The remote tx version is obtained the via TransactionContext which may not be available yet so
+ // we pass a Supplier to dynamically obtain it. Once the ready Future is resolved the
+ // TransactionContext is available.
+ Supplier<Short> txVersionSupplier = () -> wrapper.getTransactionContext().getTransactionVersion();
- cohorts.add(new ThreePhaseCommitCohortProxy.CohortInfo(wrapper.readyTransaction(), txVersionSupplier));
+ cohorts.add(new ThreePhaseCommitCohortProxy.CohortInfo(wrapper.readyTransaction(), txVersionSupplier));
+ }
}
return new ThreePhaseCommitCohortProxy(txContextFactory.getActorContext(), cohorts, getIdentifier());
Code Review / controller.git / blobdiff