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