Bug 2340: Fixed chained Tx not ready prior next create 59/12659/1
authortpantelis <tpanteli@brocade.com>
Sun, 2 Nov 2014 21:44:34 +0000 (16:44 -0500)
committertpantelis <tpanteli@brocade.com>
Mon, 3 Nov 2014 01:32:08 +0000 (20:32 -0500)
On new*Transaction, utilized the new State classes to obtain
the previous Tx's ready Futures and pass then to the new
ChainedTransactionProxy. This makes it deterministic so that
a Tx will always get ready Futures from the previous Tx.

Change-Id: Icc017285bd5ceb118e98d3e38ec9a10a9144155e
Signed-off-by: tpantelis <tpanteli@brocade.com>
opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionChainProxy.java
opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionProxy.java
opendaylight/md-sal/sal-distributed-datastore/src/test/java/org/opendaylight/controller/cluster/datastore/DistributedDataStoreIntegrationTest.java

index 2e671e3ce2f267807837225c95376847c6116eb8..87959efe8ae2def5684e253f2e0840c7177db838 100644 (file)
@@ -11,11 +11,9 @@ package org.opendaylight.controller.cluster.datastore;
 import akka.actor.ActorSelection;
 import akka.dispatch.OnComplete;
 import com.google.common.base.Preconditions;
-import java.util.AbstractMap.SimpleEntry;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
 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;
@@ -38,39 +36,31 @@ public class TransactionChainProxy implements DOMStoreTransactionChain {
     private interface State {
         boolean isReady();
 
-        SimpleEntry<Object, List<Future<ActorSelection>>> getReadyFutures();
-
-        void setReadyFutures(Object txIdentifier, List<Future<ActorSelection>> readyFutures);
+        List<Future<ActorSelection>> getPreviousReadyFutures();
     }
 
     private static class Allocated implements State {
-        private volatile SimpleEntry<Object, List<Future<ActorSelection>>> readyFutures;
+        private final ChainedTransactionProxy transaction;
 
-        @Override
-        public boolean isReady() {
-            return readyFutures != null;
+        Allocated(ChainedTransactionProxy transaction) {
+            this.transaction = transaction;
         }
 
         @Override
-        public SimpleEntry<Object, List<Future<ActorSelection>>> getReadyFutures() {
-            return readyFutures != null ? readyFutures : EMPTY_READY_FUTURES;
+        public boolean isReady() {
+            return transaction.isReady();
         }
 
         @Override
-        public void setReadyFutures(Object txIdentifier, List<Future<ActorSelection>> readyFutures) {
-            this.readyFutures = new SimpleEntry<>(txIdentifier, readyFutures);
+        public List<Future<ActorSelection>> getPreviousReadyFutures() {
+            return transaction.getReadyFutures();
         }
     }
 
     private static abstract class AbstractDefaultState implements State {
         @Override
-        public SimpleEntry<Object, List<Future<ActorSelection>>> getReadyFutures() {
-            return EMPTY_READY_FUTURES;
-        }
-
-        @Override
-        public void setReadyFutures(Object txIdentifier, List<Future<ActorSelection>> readyFutures) {
-            throw new IllegalStateException("No transaction is allocated");
+        public List<Future<ActorSelection>> getPreviousReadyFutures() {
+            return Collections.emptyList();
         }
     }
 
@@ -88,21 +78,15 @@ public class TransactionChainProxy implements DOMStoreTransactionChain {
         }
     };
 
-    private static final SimpleEntry<Object, List<Future<ActorSelection>>> EMPTY_READY_FUTURES =
-            new SimpleEntry<Object, List<Future<ActorSelection>>>("",
-                    Collections.<Future<ActorSelection>>emptyList());
-
-    private static final AtomicReferenceFieldUpdater<TransactionChainProxy, State> STATE_UPDATER =
-            AtomicReferenceFieldUpdater.newUpdater(TransactionChainProxy.class, State.class, "state");
+    private static final AtomicInteger counter = new AtomicInteger(0);
 
     private final ActorContext actorContext;
     private final String transactionChainId;
-    private volatile State state = IDLE_STATE;
-    private static final AtomicInteger counter = new AtomicInteger(0);
+    private volatile State currentState = IDLE_STATE;
 
     public TransactionChainProxy(ActorContext actorContext) {
         this.actorContext = actorContext;
-        transactionChainId = actorContext.getCurrentMemberName() + "-transaction-chain-" + counter.incrementAndGet();
+        transactionChainId = actorContext.getCurrentMemberName() + "-txn-chain-" + counter.incrementAndGet();
     }
 
     public String getTransactionChainId() {
@@ -111,8 +95,11 @@ public class TransactionChainProxy implements DOMStoreTransactionChain {
 
     @Override
     public DOMStoreReadTransaction newReadOnlyTransaction() {
-        checkReadyState();
-        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
@@ -127,36 +114,61 @@ public class TransactionChainProxy implements DOMStoreTransactionChain {
 
     @Override
     public void close() {
-        state = CLOSED_STATE;
+        currentState = CLOSED_STATE;
 
         // Send a close transaction chain request to each and every shard
         actorContext.broadcast(new CloseTransactionChain(transactionChainId));
     }
 
     private ChainedTransactionProxy allocateWriteTransaction(TransactionProxy.TransactionType type) {
-        checkReadyState();
+        State localState = currentState;
+
+        checkReadyState(localState);
 
-        ChainedTransactionProxy txProxy = new ChainedTransactionProxy(actorContext, type);
-        STATE_UPDATER.compareAndSet(this, IDLE_STATE, new Allocated());
+        // Pass the ready Futures from the previous Tx.
+        ChainedTransactionProxy txProxy = new ChainedTransactionProxy(actorContext, type,
+                transactionChainId, localState.getPreviousReadyFutures());
+
+        currentState = new Allocated(txProxy);
 
         return txProxy;
     }
 
-    private void checkReadyState() {
-        Preconditions.checkState(state.isReady(), "Previous transaction %s is not ready yet",
-                state.getReadyFutures().getKey());
+    private void checkReadyState(State state) {
+        Preconditions.checkState(state.isReady(), "Previous transaction is not ready yet");
     }
 
-    private class ChainedTransactionProxy extends TransactionProxy {
+    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;
 
-        ChainedTransactionProxy(ActorContext actorContext, TransactionType transactionType) {
+        private ChainedTransactionProxy(ActorContext actorContext, TransactionType transactionType,
+                String transactionChainId, List<Future<ActorSelection>> previousReadyFutures) {
             super(actorContext, transactionType, transactionChainId);
+            this.previousReadyFutures = previousReadyFutures;
+        }
+
+        List<Future<ActorSelection>> getReadyFutures() {
+            return readyFutures;
+        }
+
+        boolean isReady() {
+            return readyFutures != null;
         }
 
         @Override
         protected void onTransactionReady(List<Future<ActorSelection>> readyFutures) {
-            LOG.debug("onTransactionReady {} pending readyFutures size {} chain {}", getIdentifier(), readyFutures.size(), TransactionChainProxy.this.transactionChainId);
-            state.setReadyFutures(getIdentifier(), readyFutures);
+            LOG.debug("onTransactionReady {} pending readyFutures size {} chain {}", getIdentifier(),
+                    readyFutures.size(), getTransactionChainId());
+            this.readyFutures = readyFutures;
         }
 
         /**
@@ -169,32 +181,13 @@ public class TransactionChainProxy implements DOMStoreTransactionChain {
                 final Object serializedCreateMessage) {
 
             // Check if there are any previous ready Futures, otherwise let the super class handle it.
-            // The second check is done to ensure the the previous ready Futures aren't for this
-            // Tx instance as deadlock would occur if we tried to wait on our own Futures. This can
-            // occur in this scenario:
-            //
-            //     - the TransactionProxy is created and the client does a write.
-            //
-            //     - the TransactionProxy then attempts to create the shard Tx. However it first
-            //       sends a FindPrimaryShard message to the shard manager to find the local shard
-            //       This call is done async.
-            //
-            //     - the client submits the Tx and the TransactionProxy is readied and we cache
-            //       the ready Futures here.
-            //
-            //     - then the FindPrimaryShard call completes and this method is called to create
-            //       the shard Tx. However the cached Futures were from the ready on this Tx. If we
-            //       tried to wait on them, it would cause a form of deadlock as the ready Future
-            //       would be waiting on the Tx create Future and vice versa.
-            SimpleEntry<Object, List<Future<ActorSelection>>> readyFuturesEntry = state.getReadyFutures();
-            List<Future<ActorSelection>> readyFutures = readyFuturesEntry.getValue();
-            if(readyFutures.isEmpty() || getIdentifier().equals(readyFuturesEntry.getKey())) {
+            if(previousReadyFutures.isEmpty()) {
                 return super.sendCreateTransaction(shard, serializedCreateMessage);
             }
 
             // Combine the ready Futures into 1.
             Future<Iterable<ActorSelection>> combinedFutures = akka.dispatch.Futures.sequence(
-                    readyFutures, actorContext.getActorSystem().dispatcher());
+                    previousReadyFutures, getActorContext().getActorSystem().dispatcher());
 
             // Add a callback for completion of the combined Futures.
             final Promise<Object> createTxPromise = akka.dispatch.Futures.promise();
@@ -205,15 +198,18 @@ public class TransactionChainProxy implements DOMStoreTransactionChain {
                         // 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(actorContext.executeOperationAsync(shard,
+                        createTxPromise.completeWith(getActorContext().executeOperationAsync(shard,
                                 serializedCreateMessage));
                     }
                 }
             };
 
-            combinedFutures.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+            combinedFutures.onComplete(onComplete, getActorContext().getActorSystem().dispatcher());
 
             return createTxPromise.future();
         }
index 226ac75467ff17e7066650e72cb875609bf418cd..443e0af9e031392fe1ebb08d03d956b883b91dab 100644 (file)
@@ -534,6 +534,10 @@ public class TransactionProxy implements DOMStoreReadWriteTransaction {
         return transactionChainId;
     }
 
+    protected ActorContext getActorContext() {
+        return actorContext;
+    }
+
     /**
      * Interface for a transaction operation to be invoked later.
      */
index 4f1a02e43557298c11c78f37a35c16078df4d0d7..9f5aded3521b7c72f9b50fff77a988263f1e039d 100644 (file)
@@ -9,6 +9,8 @@ import akka.actor.PoisonPill;
 import com.google.common.base.Optional;
 import com.google.common.util.concurrent.CheckedFuture;
 import com.google.common.util.concurrent.Uninterruptibles;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.concurrent.Callable;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
@@ -633,6 +635,60 @@ public class DistributedDataStoreIntegrationTest extends AbstractActorTest {
         }};
     }
 
+    @Test
+    public void testCreateChainedTransactionsInQuickSuccession() throws Exception{
+        new IntegrationTestKit(getSystem()) {{
+            DistributedDataStore dataStore = setupDistributedDataStore(
+                    "testCreateChainedTransactionsInQuickSuccession", "test-1");
+
+            DOMStoreTransactionChain txChain = dataStore.createTransactionChain();
+
+            NormalizedNode<?, ?> testNode = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+            int nTxs = 20;
+            List<DOMStoreThreePhaseCommitCohort> cohorts = new ArrayList<>(nTxs);
+            for(int i = 0; i < nTxs; i++) {
+                DOMStoreReadWriteTransaction rwTx = txChain.newReadWriteTransaction();
+
+                rwTx.merge(TestModel.TEST_PATH, testNode);
+
+                cohorts.add(rwTx.ready());
+
+            }
+
+            for(DOMStoreThreePhaseCommitCohort cohort: cohorts) {
+                doCommit(cohort);
+            }
+
+            txChain.close();
+
+            cleanup(dataStore);
+        }};
+    }
+
+    @Test
+    public void testCreateChainedTransactionAfterEmptyTxReadied() throws Exception{
+        new IntegrationTestKit(getSystem()) {{
+            DistributedDataStore dataStore = setupDistributedDataStore(
+                    "testCreateChainedTransactionAfterEmptyTxReadied", "test-1");
+
+            DOMStoreTransactionChain txChain = dataStore.createTransactionChain();
+
+            DOMStoreReadWriteTransaction rwTx1 = txChain.newReadWriteTransaction();
+
+            rwTx1.ready();
+
+            DOMStoreReadWriteTransaction rwTx2 = txChain.newReadWriteTransaction();
+
+            Optional<NormalizedNode<?, ?>> optional = rwTx2.read(TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
+            assertEquals("isPresent", false, optional.isPresent());
+
+            txChain.close();
+
+            cleanup(dataStore);
+        }};
+    }
+
     @Test
     public void testCreateChainedTransactionWhenPreviousNotReady() throws Throwable {
         new IntegrationTestKit(getSystem()) {{