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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
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package com.oracle.truffle.js.test.threading;

import static org.junit.Assert.assertEquals;

import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.RecursiveTask;
import java.util.function.Supplier;

import org.graalvm.polyglot.Context;
import org.graalvm.polyglot.Engine;
import org.graalvm.polyglot.HostAccess;
import org.graalvm.polyglot.Value;
import org.junit.Test;

public class ForkJoinTest {

    
Language bindings and Java interop can be used to expose synchronization primitives to
Graal.js.
/**
     * Language bindings and Java interop can be used to expose synchronization primitives to
     * Graal.js.
     */
    @Test
    public void forkJoinPool() {
        final ForkJoinPool pool = new ForkJoinPool();
        int result = pool.invoke(new GraaljsFibTask(13, tl));
        assertEquals(result, 233);
        pool.shutdown();
    }

    private final Engine engine = TestUtil.newEngineBuilder().build();
    private final ThreadLocal<Value> tl = ThreadLocal.withInitial(new Supplier<Value>() {

        @Override
        public Value get() {
            String src = "(function(n) {" +
                            "   if (n <= 1) " +
                            "      return n;" +
                            "   var f1 = fib.task(n - 1);" +
                            "   f1.fork();" +
                            "   var f2 = fib.task(n - 2);" +
                            "   return f2.compute() + f1.join();" +
                            "})";

            Context cx = TestUtil.newContextBuilder().engine(engine).allowHostAccess(HostAccess.ALL).build();
            cx.getBindings("js").putMember("fib", new FibTaskCreator(tl));
            return cx.eval("js", src);
        }
    });

    public static class GraaljsFibTask extends RecursiveTask<Integer> {

        private static final long serialVersionUID = 1L;

        private final int num;
        private final ThreadLocal<Value> fib;

        public GraaljsFibTask(int num, ThreadLocal<Value> tl) {
            this.fib = tl;
            this.num = num;
        }

        @Override
        public Integer compute() {
            return fib.get().execute(num).asInt();
        }
    }

    public static class FibTaskCreator {
        private final ThreadLocal<Value> tl;

        public FibTaskCreator(ThreadLocal<Value> tl) {
            this.tl = tl;
        }

        public GraaljsFibTask task(int num) {
            return new GraaljsFibTask(num, tl);
        }
    }

}