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> IMPL_UPDATER =
  40             AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class, AbstractDOMTransactionFactory.class, "commitImpl");
  41     @SuppressWarnings("rawtypes")
  42     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, Future> FUTURE_UPDATER =
  43             AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class, Future.class, "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      *
  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, final AbstractDOMTransactionFactory<?> commitImpl) {
  68         super(identifier, storeTxFactories);
  69         this.commitImpl = Preconditions.checkNotNull(commitImpl, "commitImpl must not be null.");
  70     }
  71
  72     @Override
  73     public void put(final LogicalDatastoreType store, final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
  74         checkRunning(commitImpl);
  75         checkInstanceIdentifierReferencesData(path,data);
  76         getSubtransaction(store).write(path, data);
  77     }
  78
  79     private static void checkInstanceIdentifierReferencesData(final YangInstanceIdentifier path,
  80             final NormalizedNode<?, ?> data) {
  81         final PathArgument lastArg = path.getLastPathArgument();
  82         Preconditions.checkArgument(
  83                 (lastArg == data.getIdentifier()) || (lastArg != null && lastArg.equals(data.getIdentifier())),
  84                 "Instance identifier references %s but data identifier is %s", lastArg, data);
  85     }
  86
  87     @Override
  88     public void delete(final LogicalDatastoreType store, final YangInstanceIdentifier path) {
  89         checkRunning(commitImpl);
  90         getSubtransaction(store).delete(path);
  91     }
  92
  93     @Override
  94     public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
  95         checkRunning(commitImpl);
  96         checkInstanceIdentifierReferencesData(path, data);
  97         getSubtransaction(store).merge(path, data);
  98     }
  99
 100     @Override
 101     public boolean cancel() {
 102         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 103         if (impl != null) {
 104             LOG.trace("Transaction {} cancelled before submit", getIdentifier());
 105             FUTURE_UPDATER.lazySet(this, CANCELLED_FUTURE);
 106             closeSubtransactions();
 107             return true;
 108         }
 109
 110         // The transaction is in process of being submitted or cancelled. Busy-wait
 111         // for the corresponding future.
 112         Future<?> future;
 113         do {
 114             future = commitFuture;
 115         } while (future == null);
 116
 117         return future.cancel(false);
 118     }
 119
 120     @Deprecated
 121     @Override
 122     public ListenableFuture<RpcResult<TransactionStatus>> commit() {
 123         return AbstractDataTransaction.convertToLegacyCommitFuture(submit());
 124     }
 125
 126     @Override
 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         // FIXME: deal with errors thrown by backed (ready and submit can fail in theory)
 135         for (final T txn : txns) {
 136             cohorts.add(txn.ready());
 137         }
 138
 139         final CheckedFuture<Void, TransactionCommitFailedException> ret = impl.submit(this, cohorts);
 140         FUTURE_UPDATER.lazySet(this, ret);
 141         return ret;
 142     }
 143
 144     private void checkRunning(final AbstractDOMTransactionFactory<?> impl) {
 145         Preconditions.checkState(impl != null, "Transaction %s is no longer running", getIdentifier());
 146     }
 147
 148 }