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.md.sal.dom.broker.impl.TransactionCommitFailedExceptionMapper;
  26 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  27 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionFactory;
  28 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  29 import org.opendaylight.yangtools.yang.common.RpcResult;
  30 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  31 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  32 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  33 import org.slf4j.Logger;
  34 import org.slf4j.LoggerFactory;
  35
  36 public abstract class AbstractDOMBrokerWriteTransaction<T extends DOMStoreWriteTransaction>
  37         extends AbstractDOMBrokerTransaction<T> implements DOMDataWriteTransaction {
  38
  39     @SuppressWarnings("rawtypes")
  40     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, AbstractDOMTransactionFactory>
  41             IMPL_UPDATER = AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class,
  42                     AbstractDOMTransactionFactory.class, "commitImpl");
  43     @SuppressWarnings("rawtypes")
  44     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, Future> FUTURE_UPDATER =
  45             AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class, Future.class,
  46                     "commitFuture");
  47     private static final Logger LOG = LoggerFactory.getLogger(AbstractDOMBrokerWriteTransaction.class);
  48     private static final Future<?> CANCELLED_FUTURE = Futures.immediateCancelledFuture();
  49
  50     /**
  51      * Implementation of real commit. It also acts as an indication that
  52      * the transaction is running -- which we flip atomically using
  53      * {@link #IMPL_UPDATER}.
  54      */
  55     private volatile AbstractDOMTransactionFactory<?> commitImpl;
  56
  57     /**
  58      * Future task of transaction commit. It starts off as null, but is
  59      * set appropriately on {@link #submit()} and {@link #cancel()} via
  60      * {@link AtomicReferenceFieldUpdater#lazySet(Object, Object)}.
  61      * <p/>
  62      * Lazy set is safe for use because it is only referenced to in the
  63      * {@link #cancel()} slow path, where we will busy-wait for it. The
  64      * fast path gets the benefit of a store-store barrier instead of the
  65      * usual store-load barrier.
  66      */
  67     private volatile Future<?> commitFuture;
  68
  69     protected AbstractDOMBrokerWriteTransaction(final Object identifier,
  70             final Map<LogicalDatastoreType, ? extends DOMStoreTransactionFactory> storeTxFactories,
  71             final AbstractDOMTransactionFactory<?> commitImpl) {
  72         super(identifier, storeTxFactories);
  73         this.commitImpl = Preconditions.checkNotNull(commitImpl, "commitImpl must not be null.");
  74     }
  75
  76     @Override
  77     public void put(final LogicalDatastoreType store, final YangInstanceIdentifier path,
  78             final NormalizedNode<?, ?> data) {
  79         checkRunning(commitImpl);
  80         checkInstanceIdentifierReferencesData(path,data);
  81         getSubtransaction(store).write(path, data);
  82     }
  83
  84     private static void checkInstanceIdentifierReferencesData(final YangInstanceIdentifier path,
  85             final NormalizedNode<?, ?> data) {
  86         Preconditions.checkArgument(data != null, "Attempted to store null data at %s", path);
  87         final PathArgument lastArg = path.getLastPathArgument();
  88         Preconditions.checkArgument(
  89                 lastArg == data.getIdentifier() || lastArg != null && lastArg.equals(data.getIdentifier()),
  90                 "Instance identifier references %s but data identifier is %s", lastArg, data);
  91     }
  92
  93     @Override
  94     public void delete(final LogicalDatastoreType store, final YangInstanceIdentifier path) {
  95         checkRunning(commitImpl);
  96         getSubtransaction(store).delete(path);
  97     }
  98
  99     @Override
 100     public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path,
 101             final NormalizedNode<?, ?> data) {
 102         checkRunning(commitImpl);
 103         checkInstanceIdentifierReferencesData(path, data);
 104         getSubtransaction(store).merge(path, data);
 105     }
 106
 107     @Override
 108     public boolean cancel() {
 109         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 110         if (impl != null) {
 111             LOG.trace("Transaction {} cancelled before submit", getIdentifier());
 112             FUTURE_UPDATER.lazySet(this, CANCELLED_FUTURE);
 113             closeSubtransactions();
 114             return true;
 115         }
 116
 117         // The transaction is in process of being submitted or cancelled. Busy-wait
 118         // for the corresponding future.
 119         Future<?> future;
 120         do {
 121             future = commitFuture;
 122         }
 123         while (future == null);
 124
 125         return future.cancel(false);
 126     }
 127
 128     @Deprecated
 129     @Override
 130     public ListenableFuture<RpcResult<TransactionStatus>> commit() {
 131         return AbstractDataTransaction.convertToLegacyCommitFuture(submit());
 132     }
 133
 134     @Override
 135     @SuppressWarnings("checkstyle:illegalcatch")
 136     public CheckedFuture<Void, TransactionCommitFailedException> submit() {
 137         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 138         checkRunning(impl);
 139
 140         final Collection<T> txns = getSubtransactions();
 141         final Collection<DOMStoreThreePhaseCommitCohort> cohorts = new ArrayList<>(txns.size());
 142
 143         CheckedFuture<Void, TransactionCommitFailedException> ret;
 144         try {
 145             for (final T txn : txns) {
 146                 cohorts.add(txn.ready());
 147             }
 148
 149             ret = impl.submit(this, cohorts);
 150         } catch (RuntimeException e) {
 151             ret = Futures.immediateFailedCheckedFuture(
 152                     TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER.apply(e));
 153         }
 154         FUTURE_UPDATER.lazySet(this, ret);
 155         return ret;
 156     }
 157
 158     private void checkRunning(final AbstractDOMTransactionFactory<?> impl) {
 159         Preconditions.checkState(impl != null, "Transaction %s is no longer running", getIdentifier());
 160     }
 161
 162 }