/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.core.issue;
  
  /**
   * Short sample code illustrating locking policies in the JDK. See
   * http://jira.qos.ch/browse/LBCORE-97 for a discussion.
   * 
   * @author Joern Huxhorn
   * @author Ceki Gulcu
   */
  public class LockingInJava implements Runnable {
  
      static int THREAD_COUNT = 5;
      static Object LOCK = new Object();
      static LockingInJava[] RUNNABLE_ARRAY = new LockingInJava[THREAD_COUNT];
      static Thread[] THREAD_ARRAY = new Thread[THREAD_COUNT];
  
      private int counter = 0;
      private boolean done = false;
  
      public static void main(String args[]) throws InterruptedException {
          printEnvironmentInfo();
          execute();
          printResults();
      }
  
      public static void printEnvironmentInfo() {
          System.out.println("java.runtime.version = " + System.getProperty("java.runtime.version"));
          System.out.println("java.vendor          = " + System.getProperty("java.vendor"));
          System.out.println("java.version         = " + System.getProperty("java.version"));
          System.out.println("os.name              = " + System.getProperty("os.name"));
          System.out.println("os.version           = " + System.getProperty("os.version"));
      }
  
      public static void execute() throws InterruptedException {
          for (int i = 0; i < THREAD_COUNT; i++) {
              RUNNABLE_ARRAY[i] = new LockingInJava();
              THREAD_ARRAY[i] = new Thread(RUNNABLE_ARRAY[i]);
          }
          for (Thread t : THREAD_ARRAY) {
              t.start();
          }
          // let the threads run for a while
          Thread.sleep(10000);
  
          for (int i = THREAD_COUNT - 1; i <= 0; i--) {
              RUNNABLE_ARRAY[i].done = true;
          }
  
      }
  
      public static void printResults() {
          for (int i = 0; i < RUNNABLE_ARRAY.length; i++) {
              System.out.println("runnable[" + i + "]: " + RUNNABLE_ARRAY[i]);
          }
      }
  
      public void run() {
          for (;;) {
              synchronized (LOCK) {
                  counter++;
                  try {
                      Thread.sleep(10);
                  } catch (InterruptedException ex) {
                  }
                  if (done) {
                      return;
                  }
              }
          }
      }
  
      public String toString() {
          return "counter=" + counter;
      }
  
  }