org.apache.flink.streaming.api.operators.StoppableStreamSource 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.streaming.api.operators;
import org.apache.flink.api.common.functions.StoppableFunction;
import org.apache.flink.streaming.api.functions.source.SourceFunction;
/**
* {@link StoppableStreamSource} takes a {@link SourceFunction} that implements {@link StoppableFunction}.
*
* @param Type of the output elements
* @param Type of the source function which has to be stoppable
*/
public class StoppableStreamSource & StoppableFunction>
extends StreamSource {
private static final long serialVersionUID = -4365670858793587337L;
/**
* Takes a {@link SourceFunction} that implements {@link StoppableFunction}.
*
* @param sourceFunction
* A {@link SourceFunction} that implements {@link StoppableFunction}.
*/
public StoppableStreamSource(SRC sourceFunction) {
super(sourceFunction);
}
/**
* Marks the source a stopped and calls {@link StoppableFunction#stop()} on the user function.
*/
public void stop() {
// important: marking the source as stopped has to happen before the function is stopped.
// the flag that tracks this status is volatile, so the memory model also guarantees
// the happens-before relationship
markCanceledOrStopped();
userFunction.stop();
}
}