Github user pnowojski commented on a diff in the pull request:
https://github.com/apache/flink/pull/5983#discussion_r190553816
--- Diff:
flink-streaming-java/src/main/java/org/apache/flink/streaming/api/functions/async/TimeoutAwareAsyncFunction.java
---
@@ -0,0 +1,41 @@
+/*
+ * 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.functions.async;
+
+import org.apache.flink.annotation.PublicEvolving;
+
+/**
+ * An enhanced {@link AsyncFunction} which can handle timeouts.
+ */
+@PublicEvolving
+public interface TimeoutAwareAsyncFunction<IN, OUT> extends
AsyncFunction<IN, OUT> {
+
+ /**
+ * asyncInvoke timeout occurred.
+ * Here you can complete the result future exceptionally with timeout
exception,
+ * or complete with empty result. You can also retry to complete with
the right results.
+ *
+ * @param input element coming from an upstream task
+ * @param resultFuture to be completed with the result data
+ * @exception Exception in case of a user code error. An exception will
make the task fail and
+ * trigger fail-over process.
+ */
+ void timeout(IN input, ResultFuture<OUT> resultFuture) throws Exception;
--- End diff --
Can not we add default method here (Java 8 feature)?
---
