Nashorn Thread Safety Test

closure-jstest.js

var cl = (function() {
	var scope = {};
	var x = 0;
	
	var _id = Math.random() * 999999;
	
	scope.plus = function(v) {
		x = x + v;		
		
		return x;
	};
	
	scope.getId = function() {
		return _id;		
	};
	
	return scope;
});

NashornThreadTest.java

package test.com.inpaas.nashorn;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

import jdk.nashorn.api.scripting.ScriptObjectMirror;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

public class NashornThreadTest {

	private ScriptEngine e;
	private ScriptObjectMirror fn;
	
	@Before
	public void prepare() {
		try {
			ScriptEngineManager m = new ScriptEngineManager(); 
			this.e = m.getEngineByName("nashorn");
			
			this.fn = (ScriptObjectMirror) e.eval("load('classpath:test/com/inpaas/nashorn/closure-jstest.js'); cl;");
						
		} catch (Exception e) {
			throw new RuntimeException("Could not prepare test because: " + e.getMessage(), e);
			
		}
	}
	
	@Test
	public void singleThread() throws ScriptException {
		Object v = e.eval("var x = cl(); x.plus(2);");
		
		Assert.assertTrue("number is not Double.", v instanceof Double);		
		Assert.assertEquals("value is not 2.", 2.0, ((Number) v).doubleValue(), 0.0);
		
		v = e.eval("x.plus(2);");
		Assert.assertEquals("value is not 4.", 4.0, ((Number) v).doubleValue(), 0.0);		

	
		ScriptObjectMirror y = (ScriptObjectMirror) e.eval("cl();");
		double v_original = ((Number) v).doubleValue();
		v = y.callMember("plus", v);
		
		Assert.assertEquals("value is not equal to "+ v_original, v_original, ((Number) v).doubleValue(), 0.0);		
		
		v = e.eval("x.plus(2);");
		Assert.assertEquals("value is not 6.", 6.0, ((Number) v).doubleValue(), 0.0);		
	}
	
	@Test
	public void multiThread() throws ScriptException, InterruptedException {
		Thread[] t = new Thread[10];
		ScriptObjectMirror[] y = new ScriptObjectMirror[10];
		double[] d = new double[10];
		double[] id = new double[10];
		
		double v = 0.0;
		for(int j = 0; j < 1000; j++) {
			v+=j;
		}
		
		for (int i = 0; i < t.length; i++) {
			final int fi = i;
			
			t[i] = new Thread(() -> {
				try {
					y[fi] = (ScriptObjectMirror) e.eval("cl();");
					
					for(int j = 0; j < 1000; j++) {
						
						d[fi] = (double) y[fi].callMember("plus", j);						
						Thread.sleep(10);
					}
				} catch(Exception e) {
					d[fi] = fi;
					
				}
			});
			
			t[i].start();
		}	
		
		for (int i = 0; i < t.length; i++) {
			t[i].join();		
		}
		
		for (int i = 1; i < t.length; i++) {
			id[i] = (double) y[i].callMember("getId");
			
			Assert.assertNotEquals("ids should be different from each closure.", id[i], id[i-1], 0.0); 
			Assert.assertEquals("values should be equal to sample from all closures.", v, d[i], 0.0); 
		}
		
		
		
		
		
	}	

	
	
	
}