org.apache.flink.runtime.io.network.TaskEventDispatcher Maven / Gradle / Ivy
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* 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 org.apache.flink.runtime.io.network;
import org.apache.flink.runtime.event.TaskEvent;
import org.apache.flink.runtime.io.network.api.writer.ResultPartitionWriter;
import org.apache.flink.runtime.io.network.partition.ResultPartitionID;
import org.apache.flink.runtime.io.network.partition.consumer.LocalInputChannel;
import org.apache.flink.runtime.io.network.partition.consumer.RemoteInputChannel;
import org.apache.flink.runtime.util.event.EventListener;
import org.apache.flink.shaded.guava18.com.google.common.collect.Maps;
import java.util.Map;
/**
* The task event dispatcher dispatches events flowing backwards from a consuming task to the task
* producing the consumed result.
*
* Backwards events only work for tasks, which produce pipelined results, where both the
* producing and consuming task are running at the same time.
*/
public class TaskEventDispatcher {
private final Map registeredWriters = Maps.newHashMap();
public void registerWriterForIncomingTaskEvents(ResultPartitionID partitionId, ResultPartitionWriter writer) {
synchronized (registeredWriters) {
if (registeredWriters.put(partitionId, writer) != null) {
throw new IllegalStateException("Already registered at task event dispatcher.");
}
}
}
public void unregisterWriter(ResultPartitionWriter writer) {
synchronized (registeredWriters) {
registeredWriters.remove(writer.getPartitionId());
}
}
/**
* Publishes the event to the registered {@link ResultPartitionWriter} instances.
*
* This method is either called directly from a {@link LocalInputChannel} or the network I/O
* thread on behalf of a {@link RemoteInputChannel}.
*/
public boolean publish(ResultPartitionID partitionId, TaskEvent event) {
EventListener listener = registeredWriters.get(partitionId);
if (listener != null) {
listener.onEvent(event);
return true;
}
return false;
}
public void clearAll() {
synchronized (registeredWriters) {
registeredWriters.clear();
}
}
/**
* Returns the number of currently registered writers.
*/
int getNumberOfRegisteredWriters() {
synchronized (registeredWriters) {
return registeredWriters.size();
}
}
}