nschlimm

ThreadPoolExecutor pool = new ThreadPoolExecutor(5, 5, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>(2500));
pool.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
AsynchronousFileChannel outputfile = 
      AsynchronousFileChannel.open(Paths.get(FILE_NAME), 
                                   new HashSet<StandardOpenOption>(Arrays.asList(StandardOpenOption.WRITE, 
                                                                                 StandardOpenOption.CREATE)), pool);

nschlimm

/**
 * A class that calculates the optimal thread pool boundaries. It takes the desired target utilization and the desired
 * work queue memory consumption as input and retuns thread count and work queue capacity.
 * 
 * @author Niklas Schlimm
 * 
 */
public abstract class PoolSizeCalculator {

	/**

nschlimm

public class Performance_Benchmark_AsynchronousFileChannel_2 implements Runnable {

	private static AsynchronousFileChannel outputfile;
	private static AtomicInteger fileindex = new AtomicInteger(0);
	private static ThreadPoolExecutor pool = new ThreadPoolExecutor(1, 1, 0L, TimeUnit.MILLISECONDS,
			new LinkedBlockingQueue<Runnable>(), new ThreadFactory() {
				@Override
				public Thread newThread(Runnable r) {
					Thread t = new Thread(r);
					t.setDaemon(true);

nschlimm

Exception in thread "main" java.lang.OutOfMemoryError: unable to create new native thread
	at java.lang.Thread.start0(Native Method)
	at java.lang.Thread.start(Thread.java:691)
	at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:943)
	at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1336)
	at sun.nio.ch.AsynchronousChannelGroupImpl.executeOnPooledThread(AsynchronousChannelGroupImpl.java:188)
	at sun.nio.ch.PendingIoCache.clearPendingIoMap(PendingIoCache.java:158)
	at sun.nio.ch.PendingIoCache.close(PendingIoCache.java:115)
	at sun.nio.ch.WindowsAsynchronousFileChannelImpl.close(WindowsAsynchronousFileChannelImpl.java:147)
	at com.schlimm.java7.nio.Performance_OOM_AsynchronousFileChannel_1.main(Performance_OOM_AsynchronousFileChannel_1.java:36)

nschlimm

public class Performance_Benchmark_AsynchronousFileChannel_2 implements Runnable {

	private static AsynchronousFileChannel outputfile;
	private static AtomicInteger fileindex = new AtomicInteger(0);
	private static ExecutorService pool = Executors.newFixedThreadPool(1, new ThreadFactory() {
		@Override
		public Thread newThread(Runnable r) {
			Thread t = new Thread(r);
			t.setDaemon(true);
			return t;

nschlimm

public class ThreadPool {
...
    private static final ThreadFactory defaultThreadFactory = new ThreadFactory() {
         @Override
         public Thread newThread(Runnable r) {
             Thread t = new Thread(r);
             t.setDaemon(true);
             return t;
        }
     };

nschlimm

public class Performance_Benchmark_ConventionalFileAccessExample_1 implements Runnable {

	private static FileOutputStream outputfile;
	private static byte[] content = "Hello".getBytes();

	public static void main(String[] args) throws InterruptedException, IOException {
		try {
			System.out.println("Test: " + Performance_Benchmark_ConventionalFileAccessExample_1.class.getSimpleName());
			outputfile = new FileOutputStream(new File("E:/temp/afile.out"), true);
			Average average = new PerformanceHarness().calculatePerf(new PerformanceChecker(1000, new Performance_Benchmark_ConventionalFileAccessExample_1()), 5);

nschlimm

public class Performance_Benchmark_AsynchronousFileChannel_1 implements Runnable {

	private static AsynchronousFileChannel outputfile;
	private static int fileindex = 0;

	public static void main(String[] args) throws InterruptedException, IOException {
		try {
			System.out.println("Test: " + Performance_Benchmark_AsynchronousFileChannel_1.class.getSimpleName());
			outputfile = AsynchronousFileChannel.open(Paths.get("E:/temp/afile.out"), StandardOpenOption.WRITE,
					StandardOpenOption.CREATE, StandardOpenOption.DELETE_ON_CLOSE);

nschlimm

public class CallGraph_Default_AsynchronousFileChannel {

	private static AsynchronousFileChannel fileChannel;

	public static void main(String[] args) throws InterruptedException, IOException, ExecutionException {
		try {
			fileChannel = AsynchronousFileChannel.open(Paths.get("E:/temp/afile.out"), StandardOpenOption.READ,
					StandardOpenOption.WRITE, StandardOpenOption.CREATE, StandardOpenOption.DELETE_ON_CLOSE);
			Future<Integer> future = fileChannel.write(ByteBuffer.wrap("Hello".getBytes()), 0L);
			future.get();

nschlimm

Constant pool:
  #1 = Class              #2             //  com/schlimm/bytecode/examples/BytecodeExamples
  ...
  #42 = Class              #43            //  java/lang/String
  ...
  #65 = Methodref          #42.#66        //  java/lang/String.length:()I
  #66 = NameAndType        #67:#68        //  length:()I
  #67 = Utf8               length
  #68 = Utf8               ()I
  ...