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         Preconditions.checkArgument(data != null, "Attempted to store null data at %s", path);
  86         final PathArgument lastArg = path.getLastPathArgument();
  87         Preconditions.checkArgument(
  88                 lastArg == data.getIdentifier() || lastArg != null && lastArg.equals(data.getIdentifier()),
  89                 "Instance identifier references %s but data identifier is %s", lastArg, data);
  90     }
  91
  92     @Override
  93     public void delete(final LogicalDatastoreType store, final YangInstanceIdentifier path) {
  94         checkRunning(commitImpl);
  95         getSubtransaction(store).delete(path);
  96     }
  97
  98     @Override
  99     public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path,
 100             final NormalizedNode<?, ?> data) {
 101         checkRunning(commitImpl);
 102         checkInstanceIdentifierReferencesData(path, data);
 103         getSubtransaction(store).merge(path, data);
 104     }
 105
 106     @Override
 107     public boolean cancel() {
 108         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 109         if (impl != null) {
 110             LOG.trace("Transaction {} cancelled before submit", getIdentifier());
 111             FUTURE_UPDATER.lazySet(this, CANCELLED_FUTURE);
 112             closeSubtransactions();
 113             return true;
 114         }
 115
 116         // The transaction is in process of being submitted or cancelled. Busy-wait
 117         // for the corresponding future.
 118         Future<?> future;
 119         do {
 120             future = commitFuture;
 121         }
 122         while (future == null);
 123
 124         return future.cancel(false);
 125     }
 126
 127     @Deprecated
 128     @Override
 129     public ListenableFuture<RpcResult<TransactionStatus>> commit() {
 130         return AbstractDataTransaction.convertToLegacyCommitFuture(submit());
 131     }
 132
 133     @Override
 134     public CheckedFuture<Void, TransactionCommitFailedException> submit() {
 135         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 136         checkRunning(impl);
 137
 138         final Collection<T> txns = getSubtransactions();
 139         final Collection<DOMStoreThreePhaseCommitCohort> cohorts = new ArrayList<>(txns.size());
 140
 141         // FIXME: deal with errors thrown by backed (ready and submit can fail in theory)
 142         for (final T txn : txns) {
 143             cohorts.add(txn.ready());
 144         }
 145
 146         final CheckedFuture<Void, TransactionCommitFailedException> ret = impl.submit(this, cohorts);
 147         FUTURE_UPDATER.lazySet(this, ret);
 148         return ret;
 149     }
 150
 151     private void checkRunning(final AbstractDOMTransactionFactory<?> impl) {
 152         Preconditions.checkState(impl != null, "Transaction %s is no longer running", getIdentifier());
 153     }
 154
 155 }