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 package org.opendaylight.controller.cluster.databroker;
   9
  10 import static com.google.common.base.Preconditions.checkArgument;
  11 import static com.google.common.base.Preconditions.checkState;
  12 import static java.util.Objects.requireNonNull;
  13 import static org.opendaylight.yangtools.util.concurrent.FluentFutures.immediateFailedFluentFuture;
  14
  15 import com.google.common.base.MoreObjects.ToStringHelper;
  16 import com.google.common.util.concurrent.FluentFuture;
  17 import com.google.common.util.concurrent.Futures;
  18 import java.util.Map;
  19 import java.util.concurrent.Future;
  20 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  21 import org.opendaylight.mdsal.common.api.CommitInfo;
  22 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteTransaction;
  24 import org.opendaylight.mdsal.dom.broker.TransactionCommitFailedExceptionMapper;
  25 import org.opendaylight.mdsal.dom.spi.store.DOMStoreTransactionFactory;
  26 import org.opendaylight.mdsal.dom.spi.store.DOMStoreWriteTransaction;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  28 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  29 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 public abstract class AbstractDOMBrokerWriteTransaction<T extends DOMStoreWriteTransaction>
  34         extends AbstractDOMBrokerTransaction<T> implements DOMDataTreeWriteTransaction {
  35
  36     @SuppressWarnings("rawtypes")
  37     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, AbstractDOMTransactionFactory>
  38             IMPL_UPDATER = AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class,
  39                     AbstractDOMTransactionFactory.class, "commitImpl");
  40     @SuppressWarnings("rawtypes")
  41     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, Future> FUTURE_UPDATER =
  42             AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class, Future.class,
  43                     "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      * <p/>
  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,
  68             final AbstractDOMTransactionFactory<?> commitImpl) {
  69         super(identifier, storeTxFactories);
  70         this.commitImpl = requireNonNull(commitImpl, "commitImpl must not be null.");
  71     }
  72
  73     @Override
  74     public void put(final LogicalDatastoreType store, final YangInstanceIdentifier path, final NormalizedNode data) {
  75         checkRunning(commitImpl);
  76         checkInstanceIdentifierReferencesData(path,data);
  77         getSubtransaction(store).write(path, data);
  78     }
  79
  80     private static void checkInstanceIdentifierReferencesData(final YangInstanceIdentifier path,
  81             final NormalizedNode data) {
  82         checkArgument(data != null, "Attempted to store null data at %s", path);
  83         final PathArgument lastArg = path.getLastPathArgument();
  84         if (lastArg != null) {
  85             checkArgument(lastArg.equals(data.getIdentifier()),
  86                 "Instance identifier references %s but data identifier is %s", lastArg, data);
  87         }
  88     }
  89
  90     @Override
  91     public void delete(final LogicalDatastoreType store, final YangInstanceIdentifier path) {
  92         checkRunning(commitImpl);
  93         getSubtransaction(store).delete(path);
  94     }
  95
  96     @Override
  97     public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path, final NormalizedNode data) {
  98         checkRunning(commitImpl);
  99         checkInstanceIdentifierReferencesData(path, data);
 100         getSubtransaction(store).merge(path, data);
 101     }
 102
 103     @Override
 104     public boolean cancel() {
 105         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 106         if (impl != null) {
 107             LOG.trace("Transaction {} cancelled before submit", getIdentifier());
 108             FUTURE_UPDATER.lazySet(this, CANCELLED_FUTURE);
 109             closeSubtransaction();
 110             return true;
 111         }
 112
 113         // The transaction is in process of being submitted or cancelled. Busy-wait
 114         // for the corresponding future.
 115         Future<?> future;
 116         do {
 117             future = commitFuture;
 118         }
 119         while (future == null);
 120
 121         return future.cancel(false);
 122     }
 123
 124     @Override
 125     @SuppressWarnings("checkstyle:IllegalCatch")
 126     public FluentFuture<? extends CommitInfo> commit() {
 127         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 128         checkRunning(impl);
 129
 130         FluentFuture<? extends CommitInfo> ret;
 131         final var tx = getSubtransaction();
 132         if (tx == null) {
 133             ret = CommitInfo.emptyFluentFuture();
 134         } else {
 135             try {
 136                 ret = impl.commit(this, tx.ready());
 137             } catch (RuntimeException e) {
 138                 ret = immediateFailedFluentFuture(TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER.apply(e));
 139             }
 140         }
 141
 142         FUTURE_UPDATER.lazySet(this, ret);
 143         return ret;
 144     }
 145
 146     private void checkRunning(final AbstractDOMTransactionFactory<?> impl) {
 147         checkState(impl != null, "Transaction %s is no longer running", getIdentifier());
 148     }
 149
 150     @Override
 151     protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 152         return super.addToStringAttributes(toStringHelper).add("running", commitImpl == null);
 153     }
 154 }