X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-distributed-datastore%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fdatastore%2FTransactionProxy.java;h=59c9298499c4ed0a58961b57fe40019f15214de1;hp=e8218995809698a29baa9ebbffeaf40c49b497d1;hb=e1a6ed792b504c2978c5259f926eaa09257c694c;hpb=34b9d4875434c2450f2bde07df001cb579872a82

diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionProxy.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionProxy.java
index e821899580..59c9298499 100644
--- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionProxy.java
+++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionProxy.java
@@ -12,8 +12,6 @@ import akka.actor.ActorSelection;
 import akka.dispatch.Mapper;
 import akka.dispatch.OnComplete;
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.FinalizablePhantomReference;
-import com.google.common.base.FinalizableReferenceQueue;
 import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
@@ -21,11 +19,9 @@ import com.google.common.util.concurrent.CheckedFuture;
 import com.google.common.util.concurrent.SettableFuture;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -34,7 +30,6 @@ import javax.annotation.concurrent.GuardedBy;
 import org.opendaylight.controller.cluster.datastore.compat.PreLithiumTransactionContextImpl;
 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
 import org.opendaylight.controller.cluster.datastore.identifiers.TransactionIdentifier;
-import org.opendaylight.controller.cluster.datastore.messages.CloseTransaction;
 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
 import org.opendaylight.controller.cluster.datastore.shardstrategy.ShardStrategyFactory;
@@ -42,7 +37,6 @@ import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
 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.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
 import org.opendaylight.yangtools.util.concurrent.MappingCheckedFuture;
 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
@@ -84,6 +78,12 @@ public class TransactionProxy extends AbstractDOMStoreTransaction<TransactionIde
         }
     }
 
+    private static enum TransactionState {
+        OPEN,
+        READY,
+        CLOSED,
+    }
+
     static final Mapper<Throwable, Throwable> SAME_FAILURE_TRANSFORMER =
                                                               new Mapper<Throwable, Throwable>() {
         @Override
@@ -102,72 +102,6 @@ public class TransactionProxy extends AbstractDOMStoreTransaction<TransactionIde
     private static final FiniteDuration CREATE_TX_TRY_INTERVAL =
             FiniteDuration.create(1, TimeUnit.SECONDS);
 
-    /**
-     * Used to enqueue the PhantomReferences for read-only TransactionProxy instances. The
-     * FinalizableReferenceQueue is safe to use statically in an OSGi environment as it uses some
-     * trickery to clean up its internal thread when the bundle is unloaded.
-     */
-    private static final FinalizableReferenceQueue phantomReferenceQueue =
-                                                                  new FinalizableReferenceQueue();
-
-    /**
-     * This stores the TransactionProxyCleanupPhantomReference instances statically, This is
-     * necessary because PhantomReferences need a hard reference so they're not garbage collected.
-     * Once finalized, the TransactionProxyCleanupPhantomReference removes itself from this map
-     * and thus becomes eligible for garbage collection.
-     */
-    private static final Map<TransactionProxyCleanupPhantomReference,
-                             TransactionProxyCleanupPhantomReference> phantomReferenceCache =
-                                                                        new ConcurrentHashMap<>();
-
-    /**
-     * A PhantomReference that closes remote transactions for a TransactionProxy when it's
-     * garbage collected. This is used for read-only transactions as they're not explicitly closed
-     * by clients. So the only way to detect that a transaction is no longer in use and it's safe
-     * to clean up is when it's garbage collected. It's inexact as to when an instance will be GC'ed
-     * but TransactionProxy instances should generally be short-lived enough to avoid being moved
-     * to the old generation space and thus should be cleaned up in a timely manner as the GC
-     * runs on the young generation (eden, swap1...) space much more frequently.
-     */
-    private static class TransactionProxyCleanupPhantomReference
-                                           extends FinalizablePhantomReference<TransactionProxy> {
-
-        private final List<ActorSelection> remoteTransactionActors;
-        private final AtomicBoolean remoteTransactionActorsMB;
-        private final ActorContext actorContext;
-        private final TransactionIdentifier identifier;
-
-        protected TransactionProxyCleanupPhantomReference(TransactionProxy referent) {
-            super(referent, phantomReferenceQueue);
-
-            // Note we need to cache the relevant fields from the TransactionProxy as we can't
-            // have a hard reference to the TransactionProxy instance itself.
-
-            remoteTransactionActors = referent.remoteTransactionActors;
-            remoteTransactionActorsMB = referent.remoteTransactionActorsMB;
-            actorContext = referent.actorContext;
-            identifier = referent.getIdentifier();
-        }
-
-        @Override
-        public void finalizeReferent() {
-            LOG.trace("Cleaning up {} Tx actors for TransactionProxy {}",
-                    remoteTransactionActors.size(), identifier);
-
-            phantomReferenceCache.remove(this);
-
-            // Access the memory barrier volatile to ensure all previous updates to the
-            // remoteTransactionActors list are visible to this thread.
-
-            if(remoteTransactionActorsMB.get()) {
-                for(ActorSelection actor : remoteTransactionActors) {
-                    LOG.trace("Sending CloseTransaction to {}", actor);
-                    actorContext.sendOperationAsync(actor, CloseTransaction.INSTANCE.toSerializable());
-                }
-            }
-        }
-    }
-
     /**
      * Stores the remote Tx actors for each requested data store path to be used by the
      * PhantomReference to close the remote Tx's. This is only used for read-only Tx's. The
@@ -175,8 +109,8 @@ public class TransactionProxy extends AbstractDOMStoreTransaction<TransactionIde
      * remoteTransactionActors list so they will be visible to the thread accessing the
      * PhantomReference.
      */
-    private List<ActorSelection> remoteTransactionActors;
-    private volatile AtomicBoolean remoteTransactionActorsMB;
+    List<ActorSelection> remoteTransactionActors;
+    volatile AtomicBoolean remoteTransactionActorsMB;
 
     /**
      * Stores the create transaction results per shard.
@@ -184,10 +118,10 @@ public class TransactionProxy extends AbstractDOMStoreTransaction<TransactionIde
     private final Map<String, TransactionFutureCallback> txFutureCallbackMap = new HashMap<>();
 
     private final TransactionType transactionType;
-    private final ActorContext actorContext;
+    final ActorContext actorContext;
     private final String transactionChainId;
     private final SchemaContext schemaContext;
-    private boolean inReadyState;
+    private TransactionState state = TransactionState.OPEN;
 
     private volatile boolean initialized;
     private Semaphore operationLimiter;
@@ -293,7 +227,7 @@ public class TransactionProxy extends AbstractDOMStoreTransaction<TransactionIde
     private void checkModificationState() {
         Preconditions.checkState(transactionType != TransactionType.READ_ONLY,
                 "Modification operation on read-only transaction is not allowed");
-        Preconditions.checkState(!inReadyState,
+        Preconditions.checkState(state == TransactionState.OPEN,
                 "Transaction is sealed - further modifications are not allowed");
     }
 
@@ -326,7 +260,6 @@ public class TransactionProxy extends AbstractDOMStoreTransaction<TransactionIde
         }
     }
 
-
     @Override
     public void write(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
 
@@ -381,26 +314,34 @@ public class TransactionProxy extends AbstractDOMStoreTransaction<TransactionIde
         });
     }
 
-    @Override
-    public DOMStoreThreePhaseCommitCohort ready() {
+    private boolean seal(final TransactionState newState) {
+        if (state == TransactionState.OPEN) {
+            state = newState;
+            return true;
+        } else {
+            return false;
+        }
+    }
 
-        checkModificationState();
+    @Override
+    public AbstractThreePhaseCommitCohort ready() {
+        Preconditions.checkState(transactionType != TransactionType.READ_ONLY,
+                "Read-only transactions cannot be readied");
 
-        inReadyState = true;
+        final boolean success = seal(TransactionState.READY);
+        Preconditions.checkState(success, "Transaction %s is %s, it cannot be readied", getIdentifier(), state);
 
         LOG.debug("Tx {} Readying {} transactions for commit", getIdentifier(),
                     txFutureCallbackMap.size());
 
-        if(txFutureCallbackMap.size() == 0) {
-            onTransactionReady(Collections.<Future<ActorSelection>>emptyList());
+        if (txFutureCallbackMap.isEmpty()) {
             TransactionRateLimitingCallback.adjustRateLimitForUnusedTransaction(actorContext);
             return NoOpDOMStoreThreePhaseCommitCohort.INSTANCE;
         }
 
         throttleOperation(txFutureCallbackMap.size());
 
-        List<Future<ActorSelection>> cohortFutures = Lists.newArrayList();
-
+        List<Future<ActorSelection>> cohortFutures = new ArrayList<>(txFutureCallbackMap.size());
         for(TransactionFutureCallback txFutureCallback : txFutureCallbackMap.values()) {
 
             LOG.debug("Tx {} Readying transaction for shard {} chain {}", getIdentifier(),
@@ -425,22 +366,22 @@ public class TransactionProxy extends AbstractDOMStoreTransaction<TransactionIde
             cohortFutures.add(future);
         }
 
-        onTransactionReady(cohortFutures);
-
         return new ThreePhaseCommitCohortProxy(actorContext, cohortFutures,
             getIdentifier().toString());
     }
 
-    /**
-     * Method for derived classes to be notified when the transaction has been readied.
-     *
-     * @param cohortFutures the cohort Futures for each shard transaction.
-     */
-    protected void onTransactionReady(List<Future<ActorSelection>> cohortFutures) {
-    }
-
     @Override
     public void close() {
+        if (!seal(TransactionState.CLOSED)) {
+            if (state == TransactionState.CLOSED) {
+                // Idempotent no-op as per AutoCloseable recommendation
+                return;
+            }
+
+            throw new IllegalStateException(String.format("Transaction %s is ready, it cannot be closed",
+                getIdentifier()));
+        }
+
         for (TransactionFutureCallback txFutureCallback : txFutureCallbackMap.values()) {
             txFutureCallback.enqueueTransactionOperation(new TransactionOperation() {
                 @Override
@@ -724,9 +665,7 @@ public class TransactionProxy extends AbstractDOMStoreTransaction<TransactionIde
                     remoteTransactionActors = Lists.newArrayList();
                     remoteTransactionActorsMB = new AtomicBoolean();
 
-                    TransactionProxyCleanupPhantomReference cleanup =
-                            new TransactionProxyCleanupPhantomReference(TransactionProxy.this);
-                    phantomReferenceCache.put(cleanup, cleanup);
+                    TransactionProxyCleanupPhantomReference.track(TransactionProxy.this);
                 }
 
                 // Add the actor to the remoteTransactionActors list for access by the