aweisberg commented on code in PR #7: URL: https://github.com/apache/cassandra-accord/pull/7#discussion_r1014466261
########## accord-core/src/main/java/accord/coordinate/CheckOn.java: ########## @@ -0,0 +1,236 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package accord.coordinate; + +import java.util.function.BiConsumer; + +import accord.local.*; +import accord.primitives.*; +import accord.utils.MapReduceConsume; +import com.google.common.base.Preconditions; + +import accord.api.RoutingKey; +import accord.local.Command.ApplyOutcome; +import accord.local.Command.CommitOutcome; +import accord.local.Node.Id; +import accord.messages.CheckStatus.CheckStatusOk; +import accord.messages.CheckStatus.CheckStatusOkFull; +import accord.messages.CheckStatus.IncludeInfo; +import com.google.common.collect.Iterables; + +import java.util.Collections; + +import static accord.local.PreLoadContext.contextFor; +import static accord.local.Status.*; +import static accord.local.Status.ReplicationPhase.*; + +/** + * Check on the status of a transaction. Returns early once enough information has been achieved to meet the requested + * status for the requested {@code route}. + * + * If a command is durable (i.e. executed on a majority on all shards) this is sufficient to replicate the command locally. + */ +public class CheckOn extends CheckShards +{ + final BiConsumer<? super CheckStatusOkFull, Throwable> callback; + /** + * The epoch until which we want to persist any response for locally + */ + final ReplicationPhase sufficient; + final long untilLocalEpoch; + final AbstractRoute route; + + CheckOn(Node node, ReplicationPhase sufficient, TxnId txnId, AbstractRoute route, long srcEpoch, long untilLocalEpoch, BiConsumer<? super CheckStatusOkFull, Throwable> callback) + { + this(node, sufficient, txnId, route, route.with(route.homeKey), srcEpoch, untilLocalEpoch, callback); + } + + CheckOn(Node node, ReplicationPhase sufficient, TxnId txnId, AbstractRoute route, RoutingKeys routeWithHomeKey, long srcEpoch, long untilLocalEpoch, BiConsumer<? super CheckStatusOkFull, Throwable> callback) + { + // TODO (soon): restore behaviour of only collecting info if e.g. Committed or Executed + super(node, txnId, routeWithHomeKey, srcEpoch, IncludeInfo.All); + Preconditions.checkArgument(routeWithHomeKey.contains(route.homeKey)); + this.sufficient = sufficient; + this.route = route; + this.callback = callback; + this.untilLocalEpoch = untilLocalEpoch; + } + + // TODO: many callers only need to consult precisely executeAt.epoch remotely + public static CheckOn checkOn(ReplicationPhase sufficientStatus, Node node, TxnId txnId, AbstractRoute route, long srcEpoch, long untilLocalEpoch, BiConsumer<? super CheckStatusOkFull, Throwable> callback) + { + CheckOn checkOnCommitted = new CheckOn(node, sufficientStatus, txnId, route, srcEpoch, untilLocalEpoch, callback); + checkOnCommitted.start(); + return checkOnCommitted; + } + + public static CheckOn checkOnUncommitted(Node node, TxnId txnId, AbstractRoute route, long untilLocalEpoch, BiConsumer<? super CheckStatusOkFull, Throwable> callback) + { + return checkOn(Commit, node, txnId, route, txnId.epoch, untilLocalEpoch, callback); + } + + protected AbstractRoute route() + { + return route; + } + + @Override + protected boolean isSufficient(Id from, CheckStatusOk ok) + { + return ((CheckStatusOkFull)ok).sufficientFor(route()).compareTo(sufficient) >= 0; + } + + @Override + protected void onDone(Done done, Throwable failure) + { + if (failure != null) + { + callback.accept(null, failure); + } + else if (merged == null || merged.status == NotWitnessed) + { + callback.accept(CheckStatusOkFull.NOT_WITNESSED, null); + } + else + { + new OnDone(); + } + } + + class OnDone implements MapReduceConsume<SafeCommandStore, Void> + { + final AbstractRoute maxRoute; + final RoutingKey progressKey; + final CheckStatusOkFull full; + final ReplicationPhase sufficientTo; + final PartialTxn partialTxn; + final PartialDeps partialDeps; + + public OnDone() Review Comment: I forgot why this is a bad idea and had to read up, but basically leaking this from a constructor in a multi-threaded context is something you aren't supposed to do since you are publishing a reference to a partially constructed object. Since publication is the last line of the constructor and there is probably something in publishing this to another thread that adds the necessary barriers it might be safe. It also might be the JMM says it is unsafe. Generally I don't attempt to publish an object to other threads from the constructor. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
