/*******************************************************************************
 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.db.tests.performance.java;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Semaphore;
import java.util.concurrent.atomic.AtomicInteger;

import org.simantics.db.testing.base.TestCommonPerf;


/**
 *
 */
public class ThreadLocalTest extends TestCommonPerf {

	public void test() throws Exception {

		final ThreadLocal<AtomicInteger> local = new ThreadLocal<AtomicInteger>();
		
		class CounterThread extends Thread {

			final private Semaphore start;
			final private AtomicInteger counter;
			final private CountDownLatch latch;
			
			public CounterThread(Semaphore start, CountDownLatch latch, AtomicInteger counter) {
				this.start = start;
				this.counter = counter;
				this.latch = latch;
			}
			
			@Override
			public void run() {
				
				local.set(new AtomicInteger());
				
				try {
					start.acquire();
				} catch (InterruptedException e) {
					e.printStackTrace();
				}

				int work = 0;
				for(int i=0;i<1000000;i++) {
					for(int j=0;j<100;j++) local.get().incrementAndGet();
				}
				
				latch.countDown();
				
				System.out.println("work=" + work);
				
			}
			
		}
		
		CountDownLatch latch = new CountDownLatch(8);
		AtomicInteger counter = new AtomicInteger(0);
		Semaphore starter = new Semaphore(0);
		
		for(int i=0;i<8;i++) new CounterThread(starter, latch, counter).start();
		
		Thread.sleep(500);

		starter.release(8);
		long start = System.nanoTime();
		latch.await();
		long duration = System.nanoTime() - start;

		System.out.println("counter=" + counter.get());
		
		System.out.println("Finished in " + 1e-9*duration + "s.");
		
	}
	
	public void test2() throws Exception {

		class CounterThread extends Thread {

			final private Semaphore start;
			final private AtomicInteger counter;
			final private CountDownLatch latch;
			
			public CounterThread(Semaphore start, CountDownLatch latch, AtomicInteger counter) {
				this.start = start;
				this.counter = counter;
				this.latch = latch;
			}
			
			@Override
			public void run() {
				
				AtomicInteger ai = new AtomicInteger();
				
				try {
					start.acquire();
				} catch (InterruptedException e) {
					e.printStackTrace();
				}

				int work = 0;
				for(int i=0;i<1000000;i++) {
					for(int j=0;j<100;j++) ai.incrementAndGet();
				}
				
				latch.countDown();
				
				System.out.println("work=" + work);
				
			}
			
		}
		
		CountDownLatch latch = new CountDownLatch(8);
		AtomicInteger counter = new AtomicInteger(0);
		Semaphore starter = new Semaphore(0);
		
		for(int i=0;i<8;i++) new CounterThread(starter, latch, counter).start();
		
		Thread.sleep(500);

		starter.release(8);
		long start = System.nanoTime();
		latch.await();
		long duration = System.nanoTime() - start;

		System.out.println("counter=" + counter.get());
		
		System.out.println("Finished in " + 1e-9*duration + "s.");
		
	}

}