| /* |
| * 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 java.util.concurrent.atomic.AtomicBoolean; |
| |
| import org.apache.cassandra.utils.concurrent.Future; |
| |
| public class SingleThreadExecutorPlus extends ThreadPoolExecutorPlus implements SequentialExecutorPlus |
| { |
| public static class AtLeastOnce extends AtomicBoolean implements AtLeastOnceTrigger, Runnable |
| { |
| protected final SequentialExecutorPlus executor; |
| protected final Runnable run; |
| |
| public AtLeastOnce(SequentialExecutorPlus executor, Runnable run) |
| { |
| this.executor = executor; |
| this.run = run; |
| } |
| |
| public boolean trigger() |
| { |
| boolean success; |
| if (success = compareAndSet(false, true)) |
| executor.execute(this); |
| return success; |
| } |
| |
| public void runAfter(Runnable run) |
| { |
| executor.execute(run); |
| } |
| |
| public void sync() |
| { |
| Future<?> done = executor.submit(() -> {}); |
| done.awaitThrowUncheckedOnInterrupt(); |
| done.rethrowIfFailed(); // executor might get shutdown before we execute; propagate cancellation exception |
| } |
| |
| public void run() |
| { |
| set(false); |
| run.run(); |
| } |
| |
| @Override |
| public String toString() |
| { |
| return run.toString(); |
| } |
| } |
| |
| SingleThreadExecutorPlus(ThreadPoolExecutorBuilder<? extends SingleThreadExecutorPlus> builder) |
| { |
| this(builder, TaskFactory.standard()); |
| } |
| |
| SingleThreadExecutorPlus(ThreadPoolExecutorBuilder<? extends SingleThreadExecutorPlus> builder, TaskFactory taskFactory) |
| { |
| super(builder, taskFactory); |
| } |
| |
| @Override |
| public int getCorePoolSize() |
| { |
| return 1; |
| } |
| @Override |
| public void setCorePoolSize(int number) |
| { |
| throw new UnsupportedOperationException(); |
| } |
| @Override |
| public int getMaximumPoolSize() |
| { |
| return 1; |
| } |
| @Override |
| public void setMaximumPoolSize(int number) |
| { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public AtLeastOnce atLeastOnceTrigger(Runnable run) |
| { |
| return new AtLeastOnce(this, run); |
| } |
| } |