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