opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/DOMForwardedWriteTransaction.java

   1 /*
   2  * Copyright (c) 2014 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.md.sal.dom.broker.impl;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.base.Supplier;
  12 import com.google.common.util.concurrent.FluentFuture;
  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.data.LogicalDatastoreType;
  21 import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
  22 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  23 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  24 import org.opendaylight.mdsal.common.api.CommitInfo;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  26 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29
  30 /**
  31  * Read-Write Transaction, which is composed of several
  32  * {@link DOMStoreWriteTransaction} transactions. A sub-transaction is selected by
  33  * {@link LogicalDatastoreType} type parameter in:
  34  *
  35  * <p>
  36  * <ul>
  37  * <li>{@link #put(LogicalDatastoreType, YangInstanceIdentifier, NormalizedNode)}
  38  * <li>{@link #delete(LogicalDatastoreType, YangInstanceIdentifier)}
  39  * <li>{@link #merge(LogicalDatastoreType, YangInstanceIdentifier, NormalizedNode)}
  40  * </ul>
  41  *
  42  * <p>
  43  * {@link #commit()} will result in invocation of
  44  * {@link DOMDataCommitImplementation#submit(org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction,
  45  * Iterable)} invocation with all {@link org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort}
  46  * for underlying transactions.
  47  *
  48  * @param <T> Subtype of {@link DOMStoreWriteTransaction} which is used as
  49  *            subtransaction.
  50  */
  51 @Deprecated
  52 class DOMForwardedWriteTransaction<T extends DOMStoreWriteTransaction> extends
  53         AbstractDOMForwardedCompositeTransaction<LogicalDatastoreType, T> implements DOMDataWriteTransaction {
  54     @SuppressWarnings("rawtypes")
  55     private static final AtomicReferenceFieldUpdater<DOMForwardedWriteTransaction,
  56             AbstractDOMForwardedTransactionFactory>
  57             IMPL_UPDATER = AtomicReferenceFieldUpdater
  58             .newUpdater(DOMForwardedWriteTransaction.class, AbstractDOMForwardedTransactionFactory.class, "commitImpl");
  59     @SuppressWarnings("rawtypes")
  60     private static final AtomicReferenceFieldUpdater<DOMForwardedWriteTransaction, Future> FUTURE_UPDATER
  61             = AtomicReferenceFieldUpdater.newUpdater(DOMForwardedWriteTransaction.class, Future.class, "commitFuture");
  62     private static final Logger LOG = LoggerFactory.getLogger(DOMForwardedWriteTransaction.class);
  63     private static final Future<?> CANCELLED_FUTURE = Futures.immediateCancelledFuture();
  64
  65     /**
  66      * Implementation of real commit. It also acts as an indication that
  67      * the transaction is running -- which we flip atomically using
  68      * {@link #IMPL_UPDATER}.
  69      */
  70     private volatile AbstractDOMForwardedTransactionFactory<?> commitImpl;
  71
  72     /**
  73      * Future task of transaction commit. It starts off as null, but is
  74      * set appropriately on {@link #commit()} and {@link #cancel()} via
  75      * {@link AtomicReferenceFieldUpdater#lazySet(Object, Object)}.
  76      *
  77      * <p>
  78      * Lazy set is safe for use because it is only referenced to in the
  79      * {@link #cancel()} slow path, where we will busy-wait for it. The
  80      * fast path gets the benefit of a store-store barrier instead of the
  81      * usual store-load barrier.
  82      */
  83     private volatile Future<?> commitFuture;
  84
  85     protected DOMForwardedWriteTransaction(final Object identifier, final Map<LogicalDatastoreType, T> backingTxs,
  86                                            final AbstractDOMForwardedTransactionFactory<?> commitImpl) {
  87         super(identifier, backingTxs);
  88         this.commitImpl = Preconditions.checkNotNull(commitImpl, "commitImpl must not be null.");
  89     }
  90
  91     @Override
  92     public void put(final LogicalDatastoreType store, final YangInstanceIdentifier path,
  93                     final NormalizedNode<?, ?> data) {
  94         checkRunning(commitImpl);
  95         getSubtransaction(store).write(path, data);
  96     }
  97
  98     @Override
  99     public void delete(final LogicalDatastoreType store, final YangInstanceIdentifier path) {
 100         checkRunning(commitImpl);
 101         getSubtransaction(store).delete(path);
 102     }
 103
 104     @Override
 105     public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path,
 106                       final NormalizedNode<?, ?> data) {
 107         checkRunning(commitImpl);
 108         getSubtransaction(store).merge(path, data);
 109     }
 110
 111     @Override
 112     public boolean cancel() {
 113         final AbstractDOMForwardedTransactionFactory<?> impl = IMPL_UPDATER.getAndSet(this, null);
 114         if (impl != null) {
 115             LOG.trace("Transaction {} cancelled before submit", getIdentifier());
 116             FUTURE_UPDATER.lazySet(this, CANCELLED_FUTURE);
 117             closeSubtransactions();
 118             return true;
 119         }
 120
 121         // The transaction is in process of being submitted or cancelled. Busy-wait
 122         // for the corresponding future.
 123         Future<?> future;
 124         do {
 125             future = commitFuture;
 126         } while (future == null);
 127
 128         return future.cancel(false);
 129     }
 130
 131     @Override
 132     public FluentFuture<? extends CommitInfo> commit() {
 133         return FluentFuture.from(doCommit(CommitInfo::empty));
 134     }
 135
 136     @SuppressWarnings("checkstyle:IllegalCatch")
 137     private <V> ListenableFuture<V> doCommit(Supplier<V> futureValueSupplier) {
 138         final AbstractDOMForwardedTransactionFactory<?> 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         ListenableFuture<V> ret;
 145         try {
 146             for (DOMStoreWriteTransaction txn : txns) {
 147                 cohorts.add(txn.ready());
 148             }
 149
 150             ret = impl.commit(this, cohorts, futureValueSupplier);
 151         } catch (RuntimeException e) {
 152             ret = FluentFuture.from(Futures.immediateFailedFuture(
 153                     TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER.apply(e)));
 154         }
 155         FUTURE_UPDATER.lazySet(this, ret);
 156         return ret;
 157     }
 158
 159     private void checkRunning(final AbstractDOMForwardedTransactionFactory<?> impl) {
 160         Preconditions.checkState(impl != null, "Transaction %s is no longer running", getIdentifier());
 161     }
 162 }