groovy script embedding

Script.java

import groovy.lang.*;
import org.codehaus.groovy.runtime.InvokerHelper;
import org.codehaus.groovy.control.CompilationFailedException;
import java.util.*;

public class Script {
    private static final GroovyClassLoader GCL = new GroovyClassLoader(); // XXX GroovyClassLoader is threadsafe ?

    private final Class scriptClass;

    public Script(String script) throws CompilationFailedException {
        scriptClass = GCL.parseClass(script);
    }

    public Object invoke(Binding binding) {
        groovy.lang.Script gscript = InvokerHelper.createScript(scriptClass, binding); // XXX InvokerHelper.createScript is threadsafe?
        return gscript.run();
    }

    public static void main(String[] args) throws Exception {
        String my_groovy_script_as_string = "(foo, bar) = [bar, foo];";

        final Script script = new Script(my_groovy_script_as_string);

        Runnable task = new Runnable() {
            public void run() {
                Binding binding = new Binding();
                binding.setVariable("foo", UUID.randomUUID().toString());
                binding.setVariable("bar", UUID.randomUUID().toString());
                script.invoke(binding);
            }
        };

        Thread[] pool = new Thread[] {new Thread(task), new Thread(task), new Thread(task)};

        for (Thread t : pool) t.start();
        for (Thread t : pool) t.join();
    }
}