--- /dev/null
+/*
+ * Copyright (c) 2014 Brocade Communications Systems, Inc. and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.datastore;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Iterables;
+import com.google.common.util.concurrent.AbstractFuture;
+import com.google.common.util.concurrent.AbstractListeningExecutorService;
+import com.google.common.util.concurrent.CheckedFuture;
+import com.google.common.util.concurrent.FutureCallback;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
+import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
+import org.opendaylight.controller.md.sal.dom.broker.impl.AbstractDOMDataBroker;
+import org.opendaylight.controller.md.sal.dom.broker.impl.TransactionCommitFailedExceptionMapper;
+import org.opendaylight.controller.sal.core.spi.data.DOMStore;
+import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
+import org.opendaylight.yangtools.util.DurationStatisticsTracker;
+import org.opendaylight.yangtools.util.concurrent.MappingCheckedFuture;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Implementation of DOMDataCommitExecutor that coordinates transaction commits concurrently. The 3
+ * commit phases (canCommit, preCommit, and commit) are performed serially and non-blocking
+ * (ie async) per transaction but multiple transaction commits can run concurrent.
+ *
+ * @author Thomas Pantelis
+ */
+public class ConcurrentDOMDataBroker extends AbstractDOMDataBroker {
+ private static final Logger LOG = LoggerFactory.getLogger(ConcurrentDOMDataBroker.class);
+ private static final String CAN_COMMIT = "CAN_COMMIT";
+ private static final String PRE_COMMIT = "PRE_COMMIT";
+ private static final String COMMIT = "COMMIT";
+
+ private final DurationStatisticsTracker commitStatsTracker = DurationStatisticsTracker.createConcurrent();
+
+ /**
+ * This executor is used to execute Future listener callback Runnables async.
+ */
+ private final ExecutorService clientFutureCallbackExecutor;
+
+ /**
+ * This executor is re-used internally in calls to Futures#addCallback to avoid the overhead
+ * of Futures#addCallback creating a MoreExecutors#sameThreadExecutor for each call.
+ */
+ private final ExecutorService internalFutureCallbackExecutor = new SimpleSameThreadExecutor();
+
+ public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores, ExecutorService listenableFutureExecutor) {
+ super(datastores);
+ this.clientFutureCallbackExecutor = Preconditions.checkNotNull(listenableFutureExecutor);
+ }
+
+ public DurationStatisticsTracker getCommitStatsTracker() {
+ return commitStatsTracker;
+ }
+
+ @Override
+ public CheckedFuture<Void, TransactionCommitFailedException> submit(DOMDataWriteTransaction transaction,
+ Iterable<DOMStoreThreePhaseCommitCohort> cohorts) {
+
+ Preconditions.checkArgument(transaction != null, "Transaction must not be null.");
+ Preconditions.checkArgument(cohorts != null, "Cohorts must not be null.");
+ LOG.debug("Tx: {} is submitted for execution.", transaction.getIdentifier());
+
+ final int cohortSize = Iterables.size(cohorts);
+ final AsyncNotifyingSettableFuture clientSubmitFuture =
+ new AsyncNotifyingSettableFuture(clientFutureCallbackExecutor);
+
+ doCanCommit(clientSubmitFuture, transaction, cohorts, cohortSize);
+
+ return MappingCheckedFuture.create(clientSubmitFuture,
+ TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER);
+ }
+
+ private void doCanCommit(final AsyncNotifyingSettableFuture clientSubmitFuture,
+ final DOMDataWriteTransaction transaction,
+ final Iterable<DOMStoreThreePhaseCommitCohort> cohorts, final int cohortSize) {
+
+ final long startTime = System.nanoTime();
+
+ // Not using Futures.allAsList here to avoid its internal overhead.
+ final AtomicInteger remaining = new AtomicInteger(cohortSize);
+ FutureCallback<Boolean> futureCallback = new FutureCallback<Boolean>() {
+ @Override
+ public void onSuccess(Boolean result) {
+ if (result == null || !result) {
+ handleException(clientSubmitFuture, transaction, cohorts, cohortSize,
+ CAN_COMMIT, TransactionCommitFailedExceptionMapper.CAN_COMMIT_ERROR_MAPPER,
+ new TransactionCommitFailedException(
+ "Can Commit failed, no detailed cause available."));
+ } else {
+ if(remaining.decrementAndGet() == 0) {
+ // All cohorts completed successfully - we can move on to the preCommit phase
+ doPreCommit(startTime, clientSubmitFuture, transaction, cohorts, cohortSize);
+ }
+ }
+ }
+
+ @Override
+ public void onFailure(Throwable t) {
+ handleException(clientSubmitFuture, transaction, cohorts, cohortSize, CAN_COMMIT,
+ TransactionCommitFailedExceptionMapper.CAN_COMMIT_ERROR_MAPPER, t);
+ }
+ };
+
+ for(DOMStoreThreePhaseCommitCohort cohort: cohorts) {
+ ListenableFuture<Boolean> canCommitFuture = cohort.canCommit();
+ Futures.addCallback(canCommitFuture, futureCallback, internalFutureCallbackExecutor);
+ }
+ }
+
+ private void doPreCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
+ final DOMDataWriteTransaction transaction,
+ final Iterable<DOMStoreThreePhaseCommitCohort> cohorts, final int cohortSize) {
+
+ // Not using Futures.allAsList here to avoid its internal overhead.
+ final AtomicInteger remaining = new AtomicInteger(cohortSize);
+ FutureCallback<Void> futureCallback = new FutureCallback<Void>() {
+ @Override
+ public void onSuccess(Void notUsed) {
+ if(remaining.decrementAndGet() == 0) {
+ // All cohorts completed successfully - we can move on to the commit phase
+ doCommit(startTime, clientSubmitFuture, transaction, cohorts, cohortSize);
+ }
+ }
+
+ @Override
+ public void onFailure(Throwable t) {
+ handleException(clientSubmitFuture, transaction, cohorts, cohortSize, PRE_COMMIT,
+ TransactionCommitFailedExceptionMapper.PRE_COMMIT_MAPPER, t);
+ }
+ };
+
+ for(DOMStoreThreePhaseCommitCohort cohort: cohorts) {
+ ListenableFuture<Void> preCommitFuture = cohort.preCommit();
+ Futures.addCallback(preCommitFuture, futureCallback, internalFutureCallbackExecutor);
+ }
+ }
+
+ private void doCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
+ final DOMDataWriteTransaction transaction,
+ final Iterable<DOMStoreThreePhaseCommitCohort> cohorts, final int cohortSize) {
+
+ // Not using Futures.allAsList here to avoid its internal overhead.
+ final AtomicInteger remaining = new AtomicInteger(cohortSize);
+ FutureCallback<Void> futureCallback = new FutureCallback<Void>() {
+ @Override
+ public void onSuccess(Void notUsed) {
+ if(remaining.decrementAndGet() == 0) {
+ // All cohorts completed successfully - we're done.
+ commitStatsTracker.addDuration(System.nanoTime() - startTime);
+
+ clientSubmitFuture.set();
+ }
+ }
+
+ @Override
+ public void onFailure(Throwable t) {
+ handleException(clientSubmitFuture, transaction, cohorts, cohortSize, COMMIT,
+ TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER, t);
+ }
+ };
+
+ for(DOMStoreThreePhaseCommitCohort cohort: cohorts) {
+ ListenableFuture<Void> commitFuture = cohort.commit();
+ Futures.addCallback(commitFuture, futureCallback, internalFutureCallbackExecutor);
+ }
+ }
+
+ private void handleException(final AsyncNotifyingSettableFuture clientSubmitFuture,
+ final DOMDataWriteTransaction transaction,
+ final Iterable<DOMStoreThreePhaseCommitCohort> cohorts, int cohortSize,
+ final String phase, final TransactionCommitFailedExceptionMapper exMapper,
+ final Throwable t) {
+
+ if(clientSubmitFuture.isDone()) {
+ // We must have had failures from multiple cohorts.
+ return;
+ }
+
+ LOG.warn("Tx: {} Error during phase {}, starting Abort", transaction.getIdentifier(), phase, t);
+ Exception e;
+ if(t instanceof Exception) {
+ e = (Exception)t;
+ } else {
+ e = new RuntimeException("Unexpected error occurred", t);
+ }
+
+ final TransactionCommitFailedException clientException = exMapper.apply(e);
+
+ // Transaction failed - tell all cohorts to abort.
+
+ @SuppressWarnings("unchecked")
+ ListenableFuture<Void>[] canCommitFutures = new ListenableFuture[cohortSize];
+ int i = 0;
+ for(DOMStoreThreePhaseCommitCohort cohort: cohorts) {
+ canCommitFutures[i++] = cohort.abort();
+ }
+
+ ListenableFuture<List<Void>> combinedFuture = Futures.allAsList(canCommitFutures);
+ Futures.addCallback(combinedFuture, new FutureCallback<List<Void>>() {
+ @Override
+ public void onSuccess(List<Void> notUsed) {
+ // Propagate the original exception to the client.
+ clientSubmitFuture.setException(clientException);
+ }
+
+ @Override
+ public void onFailure(Throwable t) {
+ LOG.error("Tx: {} Error during Abort.", transaction.getIdentifier(), t);
+
+ // Propagate the original exception as that is what caused the Tx to fail and is
+ // what's interesting to the client.
+ clientSubmitFuture.setException(clientException);
+ }
+ }, internalFutureCallbackExecutor);
+ }
+
+ /**
+ * A settable future that uses an {@link Executor} to execute listener callback Runnables,
+ * registered via {@link #addListener}, asynchronously when this future completes. This is
+ * done to guarantee listener executions are off-loaded onto another thread to avoid blocking
+ * the thread that completed this future, as a common use case is to pass an executor that runs
+ * tasks in the same thread as the caller (ie MoreExecutors#sameThreadExecutor)
+ * to {@link #addListener}.
+ *
+ * FIXME: This class should probably be moved to yangtools common utils for re-usability and
+ * unified with AsyncNotifyingListenableFutureTask.
+ */
+ private static class AsyncNotifyingSettableFuture extends AbstractFuture<Void> {
+
+ /**
+ * ThreadLocal used to detect if the task completion thread is running the future listener Runnables.
+ */
+ private static final ThreadLocal<Boolean> ON_TASK_COMPLETION_THREAD_TL = new ThreadLocal<Boolean>();
+
+ private final ExecutorService listenerExecutor;
+
+ AsyncNotifyingSettableFuture(ExecutorService listenerExecutor) {
+ this.listenerExecutor = listenerExecutor;
+ }
+
+ @Override
+ public void addListener(final Runnable listener, final Executor executor) {
+ // Wrap the listener Runnable in a DelegatingRunnable. If the specified executor is one
+ // that runs tasks in the same thread as the caller submitting the task
+ // (e.g. {@link com.google.common.util.concurrent.MoreExecutors#sameThreadExecutor}) and
+ // the listener is executed from the #set methods, then the DelegatingRunnable will detect
+ // this via the ThreadLocal and submit the listener Runnable to the listenerExecutor.
+ //
+ // On the other hand, if this task is already complete, the call to ExecutionList#add in
+ // superclass will execute the listener Runnable immediately and, since the ThreadLocal
+ // won't be set, the DelegatingRunnable will run the listener Runnable inline.
+ super.addListener(new DelegatingRunnable(listener, listenerExecutor), executor);
+ }
+
+ boolean set() {
+ ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
+ try {
+ return super.set(null);
+ } finally {
+ ON_TASK_COMPLETION_THREAD_TL.set(null);
+ }
+ }
+
+ @Override
+ protected boolean setException(Throwable throwable) {
+ ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
+ try {
+ return super.setException(throwable);
+ } finally {
+ ON_TASK_COMPLETION_THREAD_TL.set(null);
+ }
+ }
+
+ private static final class DelegatingRunnable implements Runnable {
+ private final Runnable delegate;
+ private final Executor executor;
+
+ DelegatingRunnable(final Runnable delegate, final Executor executor) {
+ this.delegate = Preconditions.checkNotNull(delegate);
+ this.executor = Preconditions.checkNotNull(executor);
+ }
+
+ @Override
+ public void run() {
+ if (ON_TASK_COMPLETION_THREAD_TL.get() != null) {
+ // We're running on the task completion thread so off-load to the executor.
+ LOG.trace("Submitting ListenenableFuture Runnable from thread {} to executor {}",
+ Thread.currentThread().getName(), executor);
+ executor.execute(delegate);
+ } else {
+ // We're not running on the task completion thread so run the delegate inline.
+ LOG.trace("Executing ListenenableFuture Runnable on this thread: {}",
+ Thread.currentThread().getName());
+ delegate.run();
+ }
+ }
+ }
+ }
+
+ /**
+ * A simple same-thread executor without the internal locking overhead that
+ * MoreExecutors#sameThreadExecutor has. The #execute method is the only one of concern - we
+ * don't shutdown the executor so the other methods irrelevant.
+ */
+ private static class SimpleSameThreadExecutor extends AbstractListeningExecutorService {
+
+ @Override
+ public void execute(Runnable command) {
+ command.run();
+ }
+
+ @Override
+ public boolean awaitTermination(long arg0, TimeUnit arg1) throws InterruptedException {
+ return true;
+ }
+
+ @Override
+ public boolean isShutdown() {
+ return false;
+ }
+
+ @Override
+ public boolean isTerminated() {
+ return false;
+ }
+
+ @Override
+ public void shutdown() {
+ }
+
+ @Override
+ public List<Runnable> shutdownNow() {
+ return null;
+ }
+ }
+}
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