package edu.brown.utils;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import org.voltdb.utils.Pair;

import junit.framework.TestCase;

public class TestThreadUtil extends TestCase {

    /**
     * testExceptionHandler
     */
    public void testExceptionHandler() throws Exception {
        final CountDownLatch latch = new CountDownLatch(5);
        EventObservableExceptionHandler handler = new EventObservableExceptionHandler();
        EventObserver<Pair<Thread, Throwable>> observer = new EventObserver<Pair<Thread, Throwable>>() {
            @Override
            public void update(EventObservable<Pair<Thread, Throwable>> o, Pair<Thread, Throwable> arg) {
                Thread thread = arg.getFirst();
                assertNotNull(thread);
                Throwable error = arg.getSecond();
                assertNotNull(error);
                System.err.printf("[%02d] Got Error: %s / %s\n",
                                  latch.getCount(), thread.getName(), error);
                latch.countDown();
            }
        };
        handler.addObserver(observer);
        
        Runnable r = new ExceptionHandlingRunnable() {
            @Override
            public void runImpl() {
                System.err.println("Executing failing thread!");
                throw new RuntimeException("Old and busted!");
            }
        };
        
        int poolSize = 1;
        int stackSize = 1024*128;
        ScheduledThreadPoolExecutor executor = ThreadUtil.getScheduledThreadPoolExecutor("TEST", handler, poolSize, stackSize);
        executor.scheduleWithFixedDelay(r, 1, 1, TimeUnit.SECONDS);
        
        boolean ret = latch.await(10, TimeUnit.SECONDS);
        assertTrue(ret);
    }
    
    /**
     * testRun
     */
    public void testRun() {
        final int num_threads = 100;
        final AtomicInteger ctr = new AtomicInteger(0);
        
        List<Runnable> threads = new ArrayList<Runnable>(); 
        for (int i = 0; i < num_threads; i++) {
            threads.add(new Runnable() {
                public void run() {
                    ctr.incrementAndGet();
                };
            });
        } // FOR
        
        ThreadUtil.runNewPool(threads);
        assertEquals(num_threads, ctr.get());
    }
    
}