/*
* 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.concurrent.Future;
import org.apache.flink.runtime.jobmanager.scheduler.ScheduledUnit;
/**
* The slot provider is responsible for preparing slots for ready-to-run tasks.
*
* <p>It supports two allocating modes:
* <ul>
* <li>Immediate allocating: A request for a task slot immediately gets satisfied, we can call
* {@link Future#getNow(Object)} to get the allocated slot.</li>
* <li>Queued allocating: A request for a task slot is queued and returns a future that will be
* fulfilled as soon as a slot becomes available.</li>
* </ul>
*/
public interface SlotProvider {
/**
* Allocating slot with specific requirement.
*
* @param task The task to allocate the slot for
* @param allowQueued Whether allow the task be queued if we do not have enough resource
* @return The future of the allocation
*/
Future<SimpleSlot> allocateSlot(ScheduledUnit task, boolean allowQueued);
}