content: /*
   * 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.kafka.common.utils;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.ThreadFactory;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicLong;
  
  import static java.lang.Thread.UncaughtExceptionHandler;
  
  /**
   * Utilities for working with threads.
   */
  public class ThreadUtils {
  
      private static final Logger log = LoggerFactory.getLogger(ThreadUtils.class);
  
      /**
       * Create a new ThreadFactory.
       *
       * @param pattern       The pattern to use.  If this contains %d, it will be
       *                      replaced with a thread number.  It should not contain more
       *                      than one %d.
       * @param daemon        True if we want daemon threads.
       * @return              The new ThreadFactory.
       */
      public static ThreadFactory createThreadFactory(final String pattern,
                                                      final boolean daemon) {
          return createThreadFactory(pattern, daemon, null);
      }
  
      /**
       * Create a new ThreadFactory.
       *
       * @param pattern       The pattern to use.  If this contains %d, it will be
       *                      replaced with a thread number.  It should not contain more
       *                      than one %d.
       * @param daemon        True if we want daemon threads.
       * @param ueh           thread's uncaught exception handler.
       * @return              The new ThreadFactory.
       */
      public static ThreadFactory createThreadFactory(final String pattern,
                                                      final boolean daemon,
                                                      final UncaughtExceptionHandler ueh) {
          return new ThreadFactory() {
              private final AtomicLong threadEpoch = new AtomicLong(0);
  
              @Override
              public Thread newThread(Runnable r) {
                  String threadName;
                  if (pattern.contains("%d")) {
                      threadName = String.format(pattern, threadEpoch.addAndGet(1));
                  } else {
                      threadName = pattern;
                  }
                  Thread thread = new Thread(r, threadName);
                  thread.setDaemon(daemon);
                  if (ueh != null) {
                      thread.setUncaughtExceptionHandler(ueh);
                  }
                  return thread;
              }
          };
      }
  
      /**
       * Shuts down an executor service in two phases, first by calling shutdown to reject incoming tasks,
       * and then calling shutdownNow, if necessary, to cancel any lingering tasks.
       * After the timeout/on interrupt, the service is forcefully closed.
       * This pattern of shutting down thread pool is adopted from here:
       * <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/concurrent/ExecutorService.html">ExecutorService</a>
       * @param executorService The service to shut down.
       * @param timeout         The timeout of the shutdown.
       * @param timeUnit        The time unit of the shutdown timeout.
       */
      public static void shutdownExecutorServiceQuietly(ExecutorService executorService,
                                                        long timeout,
                                                        TimeUnit timeUnit) {
          if (executorService == null) {
              return;
          }
          executorService.shutdown(); // Disable new tasks from being submitted
          try {
              // Wait a while for existing tasks to terminate
              if (!executorService.awaitTermination(timeout, timeUnit)) {
                  executorService.shutdownNow(); // Cancel currently executing tasks
                  // Wait a while for tasks to respond to being cancelled
                  if (!executorService.awaitTermination(timeout, timeUnit)) {
                      log.error("Executor {} did not terminate in time", executorService);
                  }
              }
          } catch (InterruptedException e) {
              // (Re-)Cancel if current thread also interrupted
              executorService.shutdownNow();
              // Preserve interrupt status
              Thread.currentThread().interrupt();
          }
      }
  }
  