org.nightcode.milter.util.ExecutorUtils Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jmilter Show documentation

Java implementation of the Sendmail Milter protocol.

There is a newer version: 0.8

package org.nightcode.milter.util;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Executor's utility methods.
 */
public final class ExecutorUtils {

  private static final class NamedThreadFactory implements ThreadFactory {
    private final ThreadGroup group;
    private final String namePrefix;
    private final AtomicInteger threadNumber = new AtomicInteger(1);

    private NamedThreadFactory(String prefix) {
      SecurityManager securityManager = System.getSecurityManager();
      group = (securityManager != null) ? securityManager.getThreadGroup() : Thread.currentThread().getThreadGroup();
      namePrefix = prefix + "-thread-";
    }

    @Override public Thread newThread(Runnable r) {
      Thread thread = new Thread(group, r, namePrefix + threadNumber.getAndIncrement(), 0);
      if (thread.isDaemon()) {
        thread.setDaemon(false);
      }
      if (thread.getPriority() != Thread.NORM_PRIORITY) {
        thread.setPriority(Thread.NORM_PRIORITY);
      }
      return thread;
    }
  }

  /**
   * Creates named ThreadFactory.
   *
   * @param prefix ThreadFactory's name prefix
   * @return named ThreadFactory
   */
  public static ThreadFactory namedThreadFactory(String prefix) {
    return new NamedThreadFactory(prefix);
  }

  /**
   * Trying gracefully shutdown Executor service.
   *
   * @param executorService ExecutorService
   */
  public static boolean shutdown(ExecutorService executorService) {
    executorService.shutdown();
    try {
      if (!executorService.awaitTermination(60, TimeUnit.SECONDS)) {
        executorService.shutdownNow();
        executorService.awaitTermination(30, TimeUnit.SECONDS);
      }
    } catch (InterruptedException ex) {
      executorService.shutdownNow();
      Thread.currentThread().interrupt();
    }
    return executorService.isTerminated();
  }

  private ExecutorUtils() {
    throw new AssertionError();
  }
}