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package com.sun.org.apache.xml.internal.utils;

import java.util.concurrent.atomic.AtomicInteger;

Represents a safe thread that does not inherit thread-locals and runs only once.
/** * Represents a safe thread that does not inherit thread-locals and runs only * once. */
public class SafeThread extends Thread { private volatile boolean ran = false; private static final AtomicInteger threadNumber = new AtomicInteger(1); private static String threadName() { return "SafeThread-" + threadNumber.getAndIncrement(); } public SafeThread(Runnable target) { this(null, target, threadName()); } public SafeThread(Runnable target, String name) { this(null, target, name); } public SafeThread(ThreadGroup group, Runnable target, String name) { super(group, target, name, 0, false); } public final void run() { if (Thread.currentThread() != this) { throw new IllegalStateException("The run() method in a" + " SafeThread cannot be called from another thread."); } synchronized (this) { if (!ran) { ran = true; } else { throw new IllegalStateException("The run() method in a" + " SafeThread cannot be called more than once."); } } super.run(); } }