com.hydraql.adapter.hedgedread.HedgedReadExecutor Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of hydraql-template_1.4 Show documentation
The newest version!
/*
 * 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 com.hydraql.adapter.hedgedread;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author leojie 2023/6/30 18:49
 */
public class HedgedReadExecutor {
  private static final Logger LOG = LoggerFactory.getLogger(HedgedReadExecutor.class);
  private static volatile HedgedReadExecutor executor;
  private static ThreadPoolExecutor HEDGED_READ_THREAD_POOL;

  private HedgedReadExecutor() {
  }

  public static HedgedReadExecutor create() {
    if (executor == null) {
      synchronized (HedgedReadExecutor.class) {
        if (executor == null) {
          executor = new HedgedReadExecutor();
        }
      }
    }
    return executor;
  }

  public synchronized ThreadPoolExecutor getExecutor(int num) {
    if (HEDGED_READ_THREAD_POOL != null) {
      return HEDGED_READ_THREAD_POOL;
    }

    HEDGED_READ_THREAD_POOL = new ThreadPoolExecutor(1, num, 60, TimeUnit.SECONDS,
        new SynchronousQueue<>(), new Daemon.DaemonFactory() {
          private final AtomicInteger threadIndex = new AtomicInteger(0);

          @Override
          public Thread newThread(Runnable r) {
            Thread t = super.newThread(r);
            t.setName("hedgedRead-" + threadIndex.getAndIncrement());
            return t;
          }
        }, new ThreadPoolExecutor.CallerRunsPolicy() {
          @Override
          public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {
            LOG.warn("Execution rejected, Executing in current thread");
            // will run in the current thread
            throw new RejectedExecutionException(
                "Task " + r.toString() + " rejected from " + e.toString());
          }
        });
    HEDGED_READ_THREAD_POOL.allowCoreThreadTimeOut(true);

    return HEDGED_READ_THREAD_POOL;
  }
}