package com.sina.util.dnscache.thread; import java.util.concurrent.ExecutorService; import java.util.concurrent.SynchronousQueue; import java.util.concurrent.ThreadFactory; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger; public class RealTimeThreadPool { private static final Object lock = new Object(); private static RealTimeThreadPool mInstance; private static ExecutorService executorService; public static RealTimeThreadPool getInstance() { if (null == mInstance) { synchronized (lock) { if (null == mInstance) { mInstance = new RealTimeThreadPool(); executorService = new ThreadPoolExecutor(1, 100, 120, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), new DefaultThreadFactory(),new ThreadPoolExecutor.DiscardPolicy()); } } } return mInstance; } public void execute(Runnable command) { if (null != executorService && !executorService.isShutdown()) { executorService.execute(command); } else { Thread thread = new Thread(command); thread.start(); } } /** * The default thread factory */ static class DefaultThreadFactory implements ThreadFactory { private static final AtomicInteger poolNumber = new AtomicInteger(1); private final ThreadGroup group; private final AtomicInteger threadNumber = new AtomicInteger(1); private final String namePrefix; DefaultThreadFactory() { SecurityManager s = System.getSecurityManager(); group = (s != null) ? s.getThreadGroup() : Thread.currentThread().getThreadGroup(); namePrefix = "pool-" + poolNumber.getAndIncrement() + "-thread-"; } public Thread newThread(Runnable r) { Thread t = new Thread(group, r, namePrefix + threadNumber.getAndIncrement(), 0); if (t.isDaemon()) t.setDaemon(false); if (t.getPriority() != Thread.NORM_PRIORITY) t.setPriority(Thread.NORM_PRIORITY); return t; } } }