package com.opensource;

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

/**
 * 描述：執行緒的Factory類，以便自定義執行緒名
 *
 * @author Cache John
 *
 */
public class NamedThreadFactory implements ThreadFactory
{
    static final AtomicInteger poolNumber = new AtomicInteger(1);
   
    final ThreadGroup group;
   
    final AtomicInteger threadNumber = new AtomicInteger(1);
   
    final String namePrefix;
   
    public NamedThreadFactory()
    {
        final SecurityManager s = System.getSecurityManager();
        this.group = s != null ? s.getThreadGroup() : Thread.currentThread().getThreadGroup();
        this.namePrefix = "pool-" + poolNumber.getAndIncrement() + "-thread-";
    }
   
    public NamedThreadFactory(final String name)
    {
        final SecurityManager s = System.getSecurityManager();
        this.group = s != null ? s.getThreadGroup() : Thread.currentThread().getThreadGroup();
        this.namePrefix = generateNamePrefix(name);
    }
   
    public static String generateNamePrefix(final String name)
    {
        return name + "-" + poolNumber.getAndIncrement() + "-thread-";
    }
   
    /*
     * (non-Javadoc)
     *
     * @see java.util.concurrent.ThreadFactory#newThread(java.lang.Runnable)
     */
    @Override
    public Thread newThread(final Runnable r)
    {
        // ? 潛在的問題是最後建立的這個執行緒的計數會不會超過integer的最大值
        final Thread t = new Thread(this.group, r, this.namePrefix + this.threadNumber.getAndIncrement(), 0);
        if (t.isDaemon())
        {
            t.setDaemon(false);
        }
        if (t.getPriority() != Thread.NORM_PRIORITY)
        {
            t.setPriority(Thread.NORM_PRIORITY);
        }
        return t;
    }
}