opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/AbstractDOMBrokerWriteTransaction.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.cluster.databroker;
  10
  11 import com.google.common.base.MoreObjects.ToStringHelper;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.util.concurrent.CheckedFuture;
  14 import com.google.common.util.concurrent.FluentFuture;
  15 import com.google.common.util.concurrent.Futures;
  16 import com.google.common.util.concurrent.MoreExecutors;
  17 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  18 import java.util.ArrayList;
  19 import java.util.Collection;
  20 import java.util.Map;
  21 import java.util.concurrent.Future;
  22 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  23 import org.opendaylight.mdsal.common.api.CommitInfo;
  24 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  25 import org.opendaylight.mdsal.common.api.MappingCheckedFuture;
  26 import org.opendaylight.mdsal.common.api.TransactionCommitFailedException;
  27 import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteTransaction;
  28 import org.opendaylight.mdsal.dom.broker.TransactionCommitFailedExceptionMapper;
  29 import org.opendaylight.mdsal.dom.spi.store.DOMStoreThreePhaseCommitCohort;
  30 import org.opendaylight.mdsal.dom.spi.store.DOMStoreTransactionFactory;
  31 import org.opendaylight.mdsal.dom.spi.store.DOMStoreWriteTransaction;
  32 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  33 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  34 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37
  38 public abstract class AbstractDOMBrokerWriteTransaction<T extends DOMStoreWriteTransaction>
  39         extends AbstractDOMBrokerTransaction<T> implements DOMDataTreeWriteTransaction {
  40
  41     @SuppressWarnings("rawtypes")
  42     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, AbstractDOMTransactionFactory>
  43             IMPL_UPDATER = AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class,
  44                     AbstractDOMTransactionFactory.class, "commitImpl");
  45     @SuppressWarnings("rawtypes")
  46     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, Future> FUTURE_UPDATER =
  47             AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class, Future.class,
  48                     "commitFuture");
  49     private static final Logger LOG = LoggerFactory.getLogger(AbstractDOMBrokerWriteTransaction.class);
  50     private static final Future<?> CANCELLED_FUTURE = Futures.immediateCancelledFuture();
  51
  52     /**
  53      * Implementation of real commit. It also acts as an indication that
  54      * the transaction is running -- which we flip atomically using
  55      * {@link #IMPL_UPDATER}.
  56      */
  57     private volatile AbstractDOMTransactionFactory<?> commitImpl;
  58
  59     /**
  60      * Future task of transaction commit. It starts off as null, but is
  61      * set appropriately on {@link #submit()} and {@link #cancel()} via
  62      * {@link AtomicReferenceFieldUpdater#lazySet(Object, Object)}.
  63      * <p/>
  64      * Lazy set is safe for use because it is only referenced to in the
  65      * {@link #cancel()} slow path, where we will busy-wait for it. The
  66      * fast path gets the benefit of a store-store barrier instead of the
  67      * usual store-load barrier.
  68      */
  69     private volatile Future<?> commitFuture;
  70
  71     protected AbstractDOMBrokerWriteTransaction(final Object identifier,
  72             final Map<LogicalDatastoreType, ? extends DOMStoreTransactionFactory> storeTxFactories,
  73             final AbstractDOMTransactionFactory<?> commitImpl) {
  74         super(identifier, storeTxFactories);
  75         this.commitImpl = Preconditions.checkNotNull(commitImpl, "commitImpl must not be null.");
  76     }
  77
  78     @Override
  79     public void put(final LogicalDatastoreType store, final YangInstanceIdentifier path,
  80             final NormalizedNode<?, ?> data) {
  81         checkRunning(commitImpl);
  82         checkInstanceIdentifierReferencesData(path,data);
  83         getSubtransaction(store).write(path, data);
  84     }
  85
  86     @SuppressFBWarnings(value = "NP_NULL_PARAM_DEREF", justification = "Unrecognised NullableDecl")
  87     private static void checkInstanceIdentifierReferencesData(final YangInstanceIdentifier path,
  88             final NormalizedNode<?, ?> data) {
  89         Preconditions.checkArgument(data != null, "Attempted to store null data at %s", path);
  90         final PathArgument lastArg = path.getLastPathArgument();
  91         Preconditions.checkArgument(
  92                 lastArg == data.getIdentifier() || lastArg != null && lastArg.equals(data.getIdentifier()),
  93                 "Instance identifier references %s but data identifier is %s", lastArg, data);
  94     }
  95
  96     @Override
  97     public void delete(final LogicalDatastoreType store, final YangInstanceIdentifier path) {
  98         checkRunning(commitImpl);
  99         getSubtransaction(store).delete(path);
 100     }
 101
 102     @Override
 103     public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path,
 104             final NormalizedNode<?, ?> data) {
 105         checkRunning(commitImpl);
 106         checkInstanceIdentifierReferencesData(path, data);
 107         getSubtransaction(store).merge(path, data);
 108     }
 109
 110     @Override
 111     public boolean cancel() {
 112         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 113         if (impl != null) {
 114             LOG.trace("Transaction {} cancelled before submit", getIdentifier());
 115             FUTURE_UPDATER.lazySet(this, CANCELLED_FUTURE);
 116             closeSubtransactions();
 117             return true;
 118         }
 119
 120         // The transaction is in process of being submitted or cancelled. Busy-wait
 121         // for the corresponding future.
 122         Future<?> future;
 123         do {
 124             future = commitFuture;
 125         }
 126         while (future == null);
 127
 128         return future.cancel(false);
 129     }
 130
 131     @Override
 132     public CheckedFuture<Void, TransactionCommitFailedException> submit() {
 133         return MappingCheckedFuture.create(commit().transform(ignored -> null,
 134                 MoreExecutors.directExecutor()), TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER);
 135     }
 136
 137     @Override
 138     @SuppressWarnings("checkstyle:IllegalCatch")
 139     public FluentFuture<? extends CommitInfo> commit() {
 140         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 141         checkRunning(impl);
 142
 143         final Collection<T> txns = getSubtransactions();
 144         final Collection<DOMStoreThreePhaseCommitCohort> cohorts = new ArrayList<>(txns.size());
 145
 146         FluentFuture<? extends CommitInfo> ret;
 147         try {
 148             for (final T txn : txns) {
 149                 cohorts.add(txn.ready());
 150             }
 151
 152             ret = impl.commit(this, cohorts);
 153         } catch (RuntimeException e) {
 154             ret = FluentFuture.from(Futures.immediateFailedFuture(
 155                     TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER.apply(e)));
 156         }
 157         FUTURE_UPDATER.lazySet(this, ret);
 158         return ret;
 159     }
 160
 161     private void checkRunning(final AbstractDOMTransactionFactory<?> impl) {
 162         Preconditions.checkState(impl != null, "Transaction %s is no longer running", getIdentifier());
 163     }
 164
 165     @Override
 166     protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 167         return super.addToStringAttributes(toStringHelper).add("running", commitImpl == null);
 168     }
 169 }