code: // from gee.cs.oswego.edu/home/jsr166/jsr166
  
  package jsr166tests.jtreg.util.concurrent.ThreadPoolExecutor;
  
  /*
   * Copyright 2007 Sun Microsystems, Inc.  All Rights Reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
   * CA 95054 USA or visit www.sun.com if you need additional information or
   * have any questions.
   */
  
  /*
   * @test
   * @bug 6450200 6450205 6450207 6450211
   * @summary Test proper handling of tasks that terminate abruptly
   * @run main/othervm -XX:-UseVMInterruptibleIO ThrowingTasks
   * @author Martin Buchholz
   */
  
  import java.security.*;
  import java.util.*;
  import java.util.concurrent.*;
  import java.util.concurrent.atomic.*;
  
  public class ThrowingTasks {
      final static Random rnd = new Random();
  
      @SuppressWarnings("serial")
      static class UncaughtExceptions
          extends ConcurrentHashMap<Class<?>, Integer> {
  
          void inc(Class<?> key) {
              for (;;) {
                  Integer i = get(key);
                  if (i == null) {
                      if (putIfAbsent(key, 1) == null)
                          return;
                  } else {
                      if (replace(key, i, i + 1))
                          return;
                  }
              }
          }
      }
  
      @SuppressWarnings("serial")
      static class UncaughtExceptionsTable
          extends Hashtable<Class<?>, Integer> {
  
          synchronized void inc(Class<?> key) {
              Integer i = get(key);
              put(key, (i == null) ? 1 : i + 1);
          }
      }
  
      final static UncaughtExceptions uncaughtExceptions
          = new UncaughtExceptions();
      final static UncaughtExceptionsTable uncaughtExceptionsTable
          = new UncaughtExceptionsTable();
      final static AtomicLong totalUncaughtExceptions
          = new AtomicLong(0);
      final static CountDownLatch uncaughtExceptionsLatch
          = new CountDownLatch(24);
  
      final static Thread.UncaughtExceptionHandler handler
          = new Thread.UncaughtExceptionHandler() {
                  public void uncaughtException(Thread t, Throwable e) {
                      check(! Thread.currentThread().isInterrupted());
                      totalUncaughtExceptions.getAndIncrement();
                      uncaughtExceptions.inc(e.getClass());
                      uncaughtExceptionsTable.inc(e.getClass());
                      uncaughtExceptionsLatch.countDown();
                  }};
  
      final static ThreadGroup tg = new ThreadGroup("Flaky");
  
      final static ThreadFactory tf = new ThreadFactory() {
              public Thread newThread(Runnable r) {
                  Thread t = new Thread(tg, r);
                  t.setUncaughtExceptionHandler(handler);
                  return t;
              }};
  
      final static RuntimeException rte = new RuntimeException();
      final static Error error = new Error();
      final static Throwable weird = new Throwable();
      final static Exception checkedException = new Exception();
  
      static class Thrower implements Runnable {
          Throwable t;
          Thrower(Throwable t) { this.t = t; }
          @SuppressWarnings("deprecation")
          public void run() { if (t != null) Thread.currentThread().stop(t); }
      }
  
      final static Thrower noThrower      = new Thrower(null);
      final static Thrower rteThrower     = new Thrower(rte);
      final static Thrower errorThrower   = new Thrower(error);
      final static Thrower weirdThrower   = new Thrower(weird);
      final static Thrower checkedThrower = new Thrower(checkedException);
  
      final static List<Thrower> throwers = Arrays.asList(
          noThrower, rteThrower, errorThrower, weirdThrower, checkedThrower);
  
      static class Flaky implements Runnable {
          final Runnable beforeExecute;
          final Runnable execute;
          Flaky(Runnable beforeExecute,
                Runnable execute) {
              this.beforeExecute = beforeExecute;
              this.execute = execute;
          }
          public void run() { execute.run(); }
      }
  
      static final List<Flaky> flakes = new ArrayList<Flaky>();
      static {
          for (Thrower x : throwers)
              for (Thrower y : throwers)
                  flakes.add(new Flaky(x, y));
          Collections.shuffle(flakes);
      }
  
      static final CountDownLatch allStarted = new CountDownLatch(flakes.size());
      static final CountDownLatch allContinue = new CountDownLatch(1);
  
      static class PermissiveSecurityManger extends SecurityManager {
          public void checkPermission(Permission p) { /* bien sur, Monsieur */ }
      }
  
      static void checkTerminated(ThreadPoolExecutor tpe) {
          try {
              check(tpe.getQueue().isEmpty());
              check(tpe.isShutdown());
              check(tpe.isTerminated());
              check(! tpe.isTerminating());
              equal(tpe.getActiveCount(), 0);
              equal(tpe.getPoolSize(), 0);
              equal(tpe.getTaskCount(), tpe.getCompletedTaskCount());
              check(tpe.awaitTermination(0, TimeUnit.SECONDS));
          } catch (Throwable t) { unexpected(t); }
      }
  
      static class CheckingExecutor extends ThreadPoolExecutor {
          CheckingExecutor() {
              super(10, 10,
                    1L, TimeUnit.HOURS,
                    new LinkedBlockingQueue<Runnable>(),
                    tf);
          }
          @Override protected void beforeExecute(Thread t, Runnable r) {
              allStarted.countDown();
              if (allStarted.getCount() < getCorePoolSize())
                  try { allContinue.await(); }
                  catch (InterruptedException x) { unexpected(x); }
              beforeExecuteCount.getAndIncrement();
              check(! isTerminated());
              ((Flaky)r).beforeExecute.run();
          }
          @Override protected void afterExecute(Runnable r, Throwable t) {
              //System.out.println(tg.activeCount());
              afterExecuteCount.getAndIncrement();
              check(((Thrower)((Flaky)r).execute).t == t);
              check(! isTerminated());
          }
          @Override protected void terminated() {
              try {
                  terminatedCount.getAndIncrement();
                  if (rnd.nextBoolean()) {
                      check(isShutdown());
                      check(isTerminating());
                      check(! isTerminated());
                      check(! awaitTermination(0L, TimeUnit.MINUTES));
                  }
              } catch (Throwable t) { unexpected(t); }
          }
      }
  
      static final AtomicInteger beforeExecuteCount = new AtomicInteger(0);
      static final AtomicInteger afterExecuteCount  = new AtomicInteger(0);
      static final AtomicInteger terminatedCount    = new AtomicInteger(0);
  
      private static void realMain(String[] args) throws Throwable {
          if (rnd.nextBoolean())
              System.setSecurityManager(new PermissiveSecurityManger());
  
          CheckingExecutor tpe = new CheckingExecutor();
  
          for (Runnable task : flakes)
              tpe.execute(task);
  
          if (rnd.nextBoolean()) {
              allStarted.await();
              equal(tpe.getTaskCount(),
                    (long) flakes.size());
              equal(tpe.getCompletedTaskCount(),
                    (long) flakes.size() - tpe.getCorePoolSize());
          }
          allContinue.countDown();
  
          //System.out.printf("thread count = %d%n", tg.activeCount());
          uncaughtExceptionsLatch.await();
  
          while (tg.activeCount() != tpe.getCorePoolSize() ||
                 tg.activeCount() != tpe.getCorePoolSize())
              Thread.sleep(10);
          equal(tg.activeCount(), tpe.getCorePoolSize());
  
          tpe.shutdown();
  
          check(tpe.awaitTermination(10L, TimeUnit.MINUTES));
          checkTerminated(tpe);
  
          //while (tg.activeCount() > 0) Thread.sleep(10);
          //System.out.println(uncaughtExceptions);
          List<Map<Class<?>, Integer>> maps
              = new ArrayList<Map<Class<?>, Integer>>();
          maps.add(uncaughtExceptions);
          maps.add(uncaughtExceptionsTable);
          for (Map<Class<?>, Integer> map : maps) {
              equal(map.get(Exception.class), throwers.size());
              equal(map.get(weird.getClass()), throwers.size());
              equal(map.get(Error.class), throwers.size() + 1 + 2);
              equal(map.get(RuntimeException.class), throwers.size() + 1);
              equal(map.size(), 4);
          }
          equal(totalUncaughtExceptions.get(), 4L*throwers.size() + 4L);
  
          equal(beforeExecuteCount.get(), flakes.size());
          equal(afterExecuteCount.get(), throwers.size());
          equal(tpe.getCompletedTaskCount(), (long) flakes.size());
          equal(terminatedCount.get(), 1);
  
          // check for termination operation idempotence
          tpe.shutdown();
          tpe.shutdownNow();
          check(tpe.awaitTermination(10L, TimeUnit.MINUTES));
          checkTerminated(tpe);
          equal(terminatedCount.get(), 1);
      }
  
      //--------------------- Infrastructure ---------------------------
      static volatile int passed = 0, failed = 0;
      static void pass() {passed++;}
      static void fail() {failed++; Thread.dumpStack();}
      static void fail(String msg) {System.out.println(msg); fail();}
      static void unexpected(Throwable t) {failed++; t.printStackTrace();}
      static void check(boolean cond) {if (cond) pass(); else fail();}
      static void equal(Object x, Object y) {
          if (x == null ? y == null : x.equals(y)) pass();
          else fail(x + " not equal to " + y);}
      public static void main(String[] args) throws Throwable {
          try {realMain(args);} catch (Throwable t) {unexpected(t);}
          System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
          if (failed > 0) throw new AssertionError("Some tests failed");}
  }
  