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.MoreObjects.ToStringHelper;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.util.concurrent.CheckedFuture;
  14 import com.google.common.util.concurrent.Futures;
  15 import com.google.common.util.concurrent.ListenableFuture;
  16 import java.util.ArrayList;
  17 import java.util.Collection;
  18 import java.util.Map;
  19 import java.util.concurrent.Future;
  20 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  21 import org.opendaylight.controller.md.sal.common.api.TransactionStatus;
  22 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  23 import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
  24 import org.opendaylight.controller.md.sal.common.impl.service.AbstractDataTransaction;
  25 import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
  26 import org.opendaylight.controller.md.sal.dom.broker.impl.TransactionCommitFailedExceptionMapper;
  27 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  28 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionFactory;
  29 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  30 import org.opendaylight.yangtools.yang.common.RpcResult;
  31 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  32 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  33 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36
  37 public abstract class AbstractDOMBrokerWriteTransaction<T extends DOMStoreWriteTransaction>
  38         extends AbstractDOMBrokerTransaction<T> implements DOMDataWriteTransaction {
  39
  40     @SuppressWarnings("rawtypes")
  41     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, AbstractDOMTransactionFactory>
  42             IMPL_UPDATER = AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class,
  43                     AbstractDOMTransactionFactory.class, "commitImpl");
  44     @SuppressWarnings("rawtypes")
  45     private static final AtomicReferenceFieldUpdater<AbstractDOMBrokerWriteTransaction, Future> FUTURE_UPDATER =
  46             AtomicReferenceFieldUpdater.newUpdater(AbstractDOMBrokerWriteTransaction.class, Future.class,
  47                     "commitFuture");
  48     private static final Logger LOG = LoggerFactory.getLogger(AbstractDOMBrokerWriteTransaction.class);
  49     private static final Future<?> CANCELLED_FUTURE = Futures.immediateCancelledFuture();
  50
  51     /**
  52      * Implementation of real commit. It also acts as an indication that
  53      * the transaction is running -- which we flip atomically using
  54      * {@link #IMPL_UPDATER}.
  55      */
  56     private volatile AbstractDOMTransactionFactory<?> commitImpl;
  57
  58     /**
  59      * Future task of transaction commit. It starts off as null, but is
  60      * set appropriately on {@link #submit()} and {@link #cancel()} via
  61      * {@link AtomicReferenceFieldUpdater#lazySet(Object, Object)}.
  62      * <p/>
  63      * Lazy set is safe for use because it is only referenced to in the
  64      * {@link #cancel()} slow path, where we will busy-wait for it. The
  65      * fast path gets the benefit of a store-store barrier instead of the
  66      * usual store-load barrier.
  67      */
  68     private volatile Future<?> commitFuture;
  69
  70     protected AbstractDOMBrokerWriteTransaction(final Object identifier,
  71             final Map<LogicalDatastoreType, ? extends DOMStoreTransactionFactory> storeTxFactories,
  72             final AbstractDOMTransactionFactory<?> commitImpl) {
  73         super(identifier, storeTxFactories);
  74         this.commitImpl = Preconditions.checkNotNull(commitImpl, "commitImpl must not be null.");
  75     }
  76
  77     @Override
  78     public void put(final LogicalDatastoreType store, final YangInstanceIdentifier path,
  79             final NormalizedNode<?, ?> data) {
  80         checkRunning(commitImpl);
  81         checkInstanceIdentifierReferencesData(path,data);
  82         getSubtransaction(store).write(path, data);
  83     }
  84
  85     private static void checkInstanceIdentifierReferencesData(final YangInstanceIdentifier path,
  86             final NormalizedNode<?, ?> data) {
  87         Preconditions.checkArgument(data != null, "Attempted to store null data at %s", path);
  88         final PathArgument lastArg = path.getLastPathArgument();
  89         Preconditions.checkArgument(
  90                 lastArg == data.getIdentifier() || lastArg != null && lastArg.equals(data.getIdentifier()),
  91                 "Instance identifier references %s but data identifier is %s", lastArg, data);
  92     }
  93
  94     @Override
  95     public void delete(final LogicalDatastoreType store, final YangInstanceIdentifier path) {
  96         checkRunning(commitImpl);
  97         getSubtransaction(store).delete(path);
  98     }
  99
 100     @Override
 101     public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path,
 102             final NormalizedNode<?, ?> data) {
 103         checkRunning(commitImpl);
 104         checkInstanceIdentifierReferencesData(path, data);
 105         getSubtransaction(store).merge(path, data);
 106     }
 107
 108     @Override
 109     public boolean cancel() {
 110         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 111         if (impl != null) {
 112             LOG.trace("Transaction {} cancelled before submit", getIdentifier());
 113             FUTURE_UPDATER.lazySet(this, CANCELLED_FUTURE);
 114             closeSubtransactions();
 115             return true;
 116         }
 117
 118         // The transaction is in process of being submitted or cancelled. Busy-wait
 119         // for the corresponding future.
 120         Future<?> future;
 121         do {
 122             future = commitFuture;
 123         }
 124         while (future == null);
 125
 126         return future.cancel(false);
 127     }
 128
 129     @Deprecated
 130     @Override
 131     public ListenableFuture<RpcResult<TransactionStatus>> commit() {
 132         return AbstractDataTransaction.convertToLegacyCommitFuture(submit());
 133     }
 134
 135     @Override
 136     @SuppressWarnings("checkstyle:illegalcatch")
 137     public CheckedFuture<Void, TransactionCommitFailedException> submit() {
 138         final AbstractDOMTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 139         checkRunning(impl);
 140
 141         final Collection<T> txns = getSubtransactions();
 142         final Collection<DOMStoreThreePhaseCommitCohort> cohorts = new ArrayList<>(txns.size());
 143
 144         CheckedFuture<Void, TransactionCommitFailedException> ret;
 145         try {
 146             for (final T txn : txns) {
 147                 cohorts.add(txn.ready());
 148             }
 149
 150             ret = impl.submit(this, cohorts);
 151         } catch (RuntimeException e) {
 152             ret = Futures.immediateFailedCheckedFuture(
 153                     TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER.apply(e));
 154         }
 155         FUTURE_UPDATER.lazySet(this, ret);
 156         return ret;
 157     }
 158
 159     private void checkRunning(final AbstractDOMTransactionFactory<?> impl) {
 160         Preconditions.checkState(impl != null, "Transaction %s is no longer running", getIdentifier());
 161     }
 162
 163     @Override
 164     protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 165         return super.addToStringAttributes(toStringHelper).add("running", commitImpl == null);
 166     }
 167 }