/*

* Copyright (c) 2013,2014 Scott Oaks. All rights reserved.

*/

package net.sdo;

import java.util.Random;

public class RandomTestJava {

private Random r = new Random();

private static int nTrials;

private static int nValues;

public static void main(String[] args) {

nTrials = Integer.parseInt(args[0]);

nValues = Integer.parseInt(args[1]);

doit(false); // warmup

doit(true);

}

public static void doit(boolean report) {

RandomTestJava rtj = new RandomTestJava();

// Java Only

double error = 0;

long then = System.currentTimeMillis();

for (int i = 0; i < nTrials; i++) {

double average = rtj.calc(nValues);

error += 50 - average;

}

long now = System.currentTimeMillis();

if (report) {

System.out.println("Error: " + error + " calcuated in Java in " + (now - then));

}

// Java Java C

error = 0;

then = System.currentTimeMillis();

for (int i = 0; i < nTrials; i++) {

double average = rtj.calcCRandom(nValues);

error += 50 - average;

}

now = System.currentTimeMillis();

if (report) {

System.out.println("Error: " + error + " calcuated in C random only in " + (now - then));

}

// Java C C

error = 0;

then = System.currentTimeMillis();

for (int i = 0; i < nTrials; i++) {

double average = rtj.calc0(nValues);

error += 50 - average;

}

now = System.currentTimeMillis();

if (report) {

System.out.println("Error: " + error + " calcuated in C in " + (now - then));

}

// C Java Java

then = System.currentTimeMillis();

error = rtj.calcFromC(nTrials, nValues);

now = System.currentTimeMillis();

if (report) {

System.out.println("Error: " + error + " calcuated from C in " + (now - then));

}

}

private native double calc0(int nValues);

private native double calcFromC(int nTrials, int nValues);

private native int getCRandom();

public double calc(int nValues) {

long d = 0;

for (int j = 0; j < nValues; j++) {

int n = r.nextInt(100) + 1;

d += n;

}

double average = d / nValues;

return average;

}

public double calcCRandom(int nValues) {

long d = 0;

for (int j = 0; j < nValues; j++) {

int n = getCRandom();

d += n;

}

double average = d / nValues;

return average;

}

static {

System.load(System.getProperty("LIBPATH") + "/libRandomTestCLibrary.so");

}

}