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.Futures;
  15 import java.util.ArrayList;
  16 import java.util.Collection;
  17 import java.util.Map;
  18 import java.util.concurrent.Future;
  19 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  20 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  21 import org.opendaylight.mdsal.common.api.TransactionCommitFailedException;
  22 import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteTransaction;
  23 import org.opendaylight.mdsal.dom.broker.TransactionCommitFailedExceptionMapper;
  24 import org.opendaylight.mdsal.dom.spi.store.DOMStoreThreePhaseCommitCohort;
  25 import org.opendaylight.mdsal.dom.spi.store.DOMStoreTransactionFactory;
  26 import org.opendaylight.mdsal.dom.spi.store.DOMStoreWriteTransaction;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  28 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  29 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 public abstract class AbstractDOMBrokerWriteTransaction<T extends DOMStoreWriteTransaction>
  34         extends AbstractDOMBrokerTransaction<T> implements DOMDataTreeWriteTransaction {
  35
  36     @SuppressWarnings("rawtypes")
  37     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, AbstractDOMTransactionFactory>
  38             IMPL_UPDATER = AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class,
  39                     AbstractDOMTransactionFactory.class, "commitImpl");
  40     @SuppressWarnings("rawtypes")
  41     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, Future> FUTURE_UPDATER =
  42             AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class, Future.class,
  43                     "commitFuture");
  44     private static final Logger LOG = LoggerFactory.getLogger(AbstractDOMBrokerWriteTransaction.class);
  45     private static final Future<?> CANCELLED_FUTURE = Futures.immediateCancelledFuture();
  46
  47     /**
  48      * Implementation of real commit. It also acts as an indication that
  49      * the transaction is running -- which we flip atomically using
  50      * {@link #IMPL_UPDATER}.
  51      */
  52     private volatile AbstractDOMTransactionFactory<?> commitImpl;
  53
  54     /**
  55      * Future task of transaction commit. It starts off as null, but is
  56      * set appropriately on {@link #submit()} and {@link #cancel()} via
  57      * {@link AtomicReferenceFieldUpdater#lazySet(Object, Object)}.
  58      * <p/>
  59      * Lazy set is safe for use because it is only referenced to in the
  60      * {@link #cancel()} slow path, where we will busy-wait for it. The
  61      * fast path gets the benefit of a store-store barrier instead of the
  62      * usual store-load barrier.
  63      */
  64     private volatile Future<?> commitFuture;
  65
  66     protected AbstractDOMBrokerWriteTransaction(final Object identifier,
  67             final Map<LogicalDatastoreType, ? extends DOMStoreTransactionFactory> storeTxFactories,
  68             final AbstractDOMTransactionFactory<?> commitImpl) {
  69         super(identifier, storeTxFactories);
  70         this.commitImpl = Preconditions.checkNotNull(commitImpl, "commitImpl must not be null.");
  71     }
  72
  73     @Override
  74     public void put(final LogicalDatastoreType store, final YangInstanceIdentifier path,
  75             final NormalizedNode<?, ?> data) {
  76         checkRunning(commitImpl);
  77         checkInstanceIdentifierReferencesData(path,data);
  78         getSubtransaction(store).write(path, data);
  79     }
  80
  81     private static void checkInstanceIdentifierReferencesData(final YangInstanceIdentifier path,
  82             final NormalizedNode<?, ?> data) {
  83         Preconditions.checkArgument(data != null, "Attempted to store null data at %s", path);
  84         final PathArgument lastArg = path.getLastPathArgument();
  85         Preconditions.checkArgument(
  86                 lastArg == data.getIdentifier() || lastArg != null && lastArg.equals(data.getIdentifier()),
  87                 "Instance identifier references %s but data identifier is %s", lastArg, data);
  88     }
  89
  90     @Override
  91     public void delete(final LogicalDatastoreType store, final YangInstanceIdentifier path) {
  92         checkRunning(commitImpl);
  93         getSubtransaction(store).delete(path);
  94     }
  95
  96     @Override
  97     public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path,
  98             final NormalizedNode<?, ?> data) {
  99         checkRunning(commitImpl);
 100         checkInstanceIdentifierReferencesData(path, data);
 101         getSubtransaction(store).merge(path, data);
 102     }
 103
 104     @Override
 105     public boolean cancel() {
 106         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 107         if (impl != null) {
 108             LOG.trace("Transaction {} cancelled before submit", getIdentifier());
 109             FUTURE_UPDATER.lazySet(this, CANCELLED_FUTURE);
 110             closeSubtransactions();
 111             return true;
 112         }
 113
 114         // The transaction is in process of being submitted or cancelled. Busy-wait
 115         // for the corresponding future.
 116         Future<?> future;
 117         do {
 118             future = commitFuture;
 119         }
 120         while (future == null);
 121
 122         return future.cancel(false);
 123     }
 124
 125     @Override
 126     @SuppressWarnings("checkstyle:illegalcatch")
 127     public CheckedFuture<Void, TransactionCommitFailedException> submit() {
 128         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 129         checkRunning(impl);
 130
 131         final Collection<T> txns = getSubtransactions();
 132         final Collection<DOMStoreThreePhaseCommitCohort> cohorts = new ArrayList<>(txns.size());
 133
 134         CheckedFuture<Void, TransactionCommitFailedException> ret;
 135         try {
 136             for (final T txn : txns) {
 137                 cohorts.add(txn.ready());
 138             }
 139
 140             ret = impl.submit(this, cohorts);
 141         } catch (RuntimeException e) {
 142             ret = Futures.immediateFailedCheckedFuture(
 143                     TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER.apply(e));
 144         }
 145         FUTURE_UPDATER.lazySet(this, ret);
 146         return ret;
 147     }
 148
 149     private void checkRunning(final AbstractDOMTransactionFactory<?> impl) {
 150         Preconditions.checkState(impl != null, "Transaction %s is no longer running", getIdentifier());
 151     }
 152
 153     @Override
 154     protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 155         return super.addToStringAttributes(toStringHelper).add("running", commitImpl == null);
 156     }
 157 }