Github user GJL commented on a diff in the pull request:
https://github.com/apache/flink/pull/5087#discussion_r155225733
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/instance/LogicalSlot.java
---
@@ -0,0 +1,115 @@
+/*
+ * 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.instance;
+
+import org.apache.flink.runtime.clusterframework.types.AllocationID;
+import org.apache.flink.runtime.jobmanager.slots.TaskManagerGateway;
+import org.apache.flink.runtime.taskmanager.TaskManagerLocation;
+
+import javax.annotation.Nullable;
+
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * A logical slot represents a resource on a TaskManager into
+ * which a single task can be deployed.
+ */
+public interface LogicalSlot {
+
+ /**
+ * Return the TaskManager location of this slot
+ *
+ * @return TaskManager location of this slot
+ */
+ TaskManagerLocation getTaskManagerLocation();
+
+ /**
+ * Return the TaskManager gateway to talk to the TaskManager.
+ *
+ * @return TaskManager gateway to talk to the TaskManager
+ */
+ TaskManagerGateway getTaskManagerGateway();
+
+ /**
+ * True if the slot is still alive.
+ *
+ * @return True if the slot is still alive, otherwise false
+ */
+ boolean isAlive();
+
+ /**
+ * Tries to assign a payload to this slot. This can only happens
+ * exactly once.
+ *
+ * @param payload to be assigned to this slot.
+ * @return true if the payload could be set, otherwise false
+ */
+ boolean tryAssignPayload(Payload payload);
+
+ /**
+ * Returns the set payload or null if none.
+ *
+ * @return Payload of this slot of null if none
+ */
+ @Nullable
+ Payload getPayload();
+
+ /**
+ * Releases this slot.
+ *
+ * @return Future which is completed once the slot has been released,
+ * in case of a failure it is completed exceptionally
+ */
+ CompletableFuture<?> releaseSlot();
+
+ /**
+ * Gets the slot number on the TaskManager.
+ *
+ * @return slot number
+ */
+ int getPhysicalSlotNumber();
+
+ /**
+ * Gets the allocation id of this slot.
+ *
+ * @return allocation id of this slot
+ */
+ AllocationID getAllocationId();
+
+ /**
+ * Payload for a logical slot.
+ */
+ interface Payload {
+
+ /**
+ * Fail the payload with the given cause.
+ *
+ * @param cause of the failure
+ */
+ void fail(Throwable cause);
--- End diff --
`Execution#fail(Throwable)` is not annotated with `@Override`.
---
