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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* published by the Free Software Foundation. Oracle designates this
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* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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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();
}
}