| /* |
| * 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.cassandra.concurrent; |
| |
| import org.apache.cassandra.utils.Shared; |
| |
| import static org.apache.cassandra.utils.Shared.Recursive.INTERFACES; |
| import static org.apache.cassandra.utils.Shared.Scope.SIMULATION; |
| |
| /** |
| * An {@link ExecutorPlus} that guarantees the order of execution matches the order of task submission, |
| * and provides a simple mechanism for the recurring pattern of ensuring a job is executed at least once |
| * after some point in time (i.e. ensures that at most one copy of the task is queued, with up to one |
| * copy running as well) |
| */ |
| @Shared(scope = SIMULATION, inner = INTERFACES) |
| public interface SequentialExecutorPlus extends ExecutorPlus |
| { |
| public interface AtLeastOnceTrigger |
| { |
| /** |
| * Ensure the job is run at least once in its entirety after this method is invoked (including any already queued) |
| */ |
| public boolean trigger(); |
| |
| /** |
| * Run the provided task after all queued and executing jobs have completed |
| */ |
| public void runAfter(Runnable run); |
| |
| /** |
| * Wait until all queued and executing jobs have completed |
| */ |
| public void sync(); |
| } |
| |
| /** |
| * Return an object for orchestrating the execution of this task at least once (in its entirety) after |
| * the trigger is invoked, i.e. saturating the number of pending tasks at 1 (2 including any possibly executing |
| * at the time of invocation) |
| */ |
| public AtLeastOnceTrigger atLeastOnceTrigger(Runnable runnable); |
| } |