nschlimm

/**
 * Custom file channel that supports the following requirements:<br>
 * - if a write task was submitted successfully, guarantee that the write operation is executed<br>
 * - if the channel is closing then throw {@link NonWritableChannelException} to notify the client, that this channel
 * isn't writable anymore
 * 
 * @author Niklas Schlimm
 * 
 */
public class GracefulAsynchronousFileChannel extends AsynchronousFileChannel {

nschlimm

public class ThreadLocalUtil {

    private final static ThreadLocal<ThreadVariables> THREAD_VARIABLES = new ThreadLocal<ThreadVariables>() {

        /**
         * @see java.lang.ThreadLocal#initialValue()
         */
        @Override
        protected ThreadVariables initialValue() {
            return new ThreadVariables();

nschlimm

ThreadPoolExecutor pool = 
       new ThreadPoolExecutor(6, 6, 
                              0L, TimeUnit.MILLISECONDS, 
                              new LinkedBlockingQueue<Runnable>(2500));
pool.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());

nschlimm

public class MyPoolSizeCalculator extends PoolSizeCalculator {

 public static void main(String[] args) throws InterruptedException, 
                                               InstantiationException, 
                                               IllegalAccessException,
                                               ClassNotFoundException {
  MyThreadSizeCalculator calculator = new MyThreadSizeCalculator();
  calculator.calculateBoundaries(new BigDecimal(1.0), 
                                 new BigDecimal(100000));
 }

nschlimm

ThreadPoolExecutor pool = 
       new ThreadPoolExecutor(0, 50, 
                              60, TimeUnit.SECONDS, 
                              new SynchronousQueue<Runnable>());
pool.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());

ThreadPoolExecutor pool = 
       new ThreadPoolExecutor(50, 50, 
                              0L, TimeUnit.MILLISECONDS, 
                              new LinkedBlockingQueue<Runnable>(100000));

nschlimm

public static ExecutorService newCachedThreadPool() {
   return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
                                 60L, TimeUnit.SECONDS,
                                 new SynchronousQueue<Runnable>());
}

public static ExecutorService newFixedThreadPool(int nThreads) {
   return new ThreadPoolExecutor(nThreads, nThreads,
                                 0L, TimeUnit.MILLISECONDS,
                                 new LinkedBlockingQueue<Runnable>());

nschlimm

public ThreadPoolExecutor(int corePoolSize,
                          int maximumPoolSize,
                          long keepAliveTime,
                          TimeUnit unit,
                          BlockingQueue<Runnable> workQueue,
                          ThreadFactory threadFactory,
                          RejectedExecutionHandler handler) { ... }

nschlimm

public class SimpleChannelClose_CompletionHandler {
...
	public static void main(String[] args) throws InterruptedException, IOException, ExecutionException {
...
			outputfile.write(ByteBuffer.wrap("Hello".getBytes()), fileindex.getAndIncrement() * 5, "", defaultCompletionHandler);
...
	}

	private static CompletionHandler<Integer, String> defaultCompletionHandler = new CompletionHandler<Integer, String>() {
		@Override

nschlimm

public class SimpleChannelClose_AsynchronousCloseException {

	private static final String FILE_NAME = "E:/temp/afile.out";
	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>());

	public static void main(String[] args) throws InterruptedException, IOException, ExecutionException {
		outputfile = AsynchronousFileChannel.open(

nschlimm

/**
 * Graceful shutdown that garantees that submitted tasks will be processed prior shutdown and that denies submission of
 * new tasks during "prepare-shutdown" phase.
 * 
 * @author Niklas Schlimm
 * 
 */
public class SimpleChannelClose_Graceful {

	private static final String FILE_NAME = "E:/temp/afile.out";