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    ExecutorService's type parameters changed between JDK5 and JDK6 in a way that makes it impossible for our invokeAll/invokeAny methods to match both at compile time. This project builds a JDK6-like copy of ExecutorService (but with JDK5 compiler settings to ensure that it will work with JRE5 at runtime). It also builds a version of AbstractExecutorService that is equivalent to a JDK5 version but using the JDK6 type parameters for the invokeAll/invokeAny methods just as with ExecutorService. This project's is then used in the bootstrap class path of Guava proper.

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    /*
 * This file is a modified version of
 * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/main/java/util/concurrent/AbstractExecutorService.java?revision=1.20
 * which contained the following notice:
 *
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/licenses/publicdomain
 */

package java.util.concurrent;

import java.util.*;

public abstract class AbstractExecutorService implements ExecutorService {

    public Future submit(Runnable task) {
        if (task == null) throw new NullPointerException();
        FutureTask ftask = new FutureTask(task, null);
        execute(ftask);
        return ftask;
    }

    public  Future submit(Runnable task, T result) {
        if (task == null) throw new NullPointerException();
        FutureTask ftask = new FutureTask(task, result);
        execute(ftask);
        return ftask;
    }

    public  Future submit(Callable task) {
        if (task == null) throw new NullPointerException();
        FutureTask ftask = new FutureTask(task);
        execute(ftask);
        return ftask;
    }

    private  T doInvokeAny(Collection> tasks,
                            boolean timed, long nanos)
        throws InterruptedException, ExecutionException, TimeoutException {
        if (tasks == null)
            throw new NullPointerException();
        int ntasks = tasks.size();
        if (ntasks == 0)
            throw new IllegalArgumentException();
        List> futures= new ArrayList>(ntasks);
        ExecutorCompletionService ecs =
            new ExecutorCompletionService(this);

        try {
            ExecutionException ee = null;
            long lastTime = (timed)? System.nanoTime() : 0;
            Iterator> it = tasks.iterator();

            futures.add(ecs.submit(it.next()));
            --ntasks;
            int active = 1;

            for (;;) {
                Future f = ecs.poll();
                if (f == null) {
                    if (ntasks > 0) {
                        --ntasks;
                        futures.add(ecs.submit(it.next()));
                        ++active;
                    }
                    else if (active == 0)
                        break;
                    else if (timed) {
                        f = ecs.poll(nanos, TimeUnit.NANOSECONDS);
                        if (f == null)
                            throw new TimeoutException();
                        long now = System.nanoTime();
                        nanos -= now - lastTime;
                        lastTime = now;
                    }
                    else
                        f = ecs.take();
                }
                if (f != null) {
                    --active;
                    try {
                        return f.get();
                    } catch (InterruptedException ie) {
                        throw ie;
                    } catch (ExecutionException eex) {
                        ee = eex;
                    } catch (RuntimeException rex) {
                        ee = new ExecutionException(rex);
                    }
                }
            }

            if (ee == null)
                ee = new ExecutionException();
            throw ee;

        } finally {
            for (Future f : futures)
                f.cancel(true);
        }
    }

    public  T invokeAny(Collection> tasks)
        throws InterruptedException, ExecutionException {
        try {
            return doInvokeAny(tasks, false, 0);
        } catch (TimeoutException cannotHappen) {
            assert false;
            return null;
        }
    }

    public  T invokeAny(Collection> tasks,
                           long timeout, TimeUnit unit)
        throws InterruptedException, ExecutionException, TimeoutException {
        return doInvokeAny(tasks, true, unit.toNanos(timeout));
    }

    public  List> invokeAll(Collection> tasks)
        throws InterruptedException {
        if (tasks == null)
            throw new NullPointerException();
        List> futures = new ArrayList>(tasks.size());
        boolean done = false;
        try {
            for (Callable t : tasks) {
                FutureTask f = new FutureTask(t);
                futures.add(f);
                execute(f);
            }
            for (Future f : futures) {
                if (!f.isDone()) {
                    try {
                        f.get();
                    } catch (CancellationException ignore) {
                    } catch (ExecutionException ignore) {
                    }
                }
            }
            done = true;
            return futures;
        } finally {
            if (!done)
                for (Future f : futures)
                    f.cancel(true);
        }
    }

    public  List> invokeAll(Collection> tasks,
                                         long timeout, TimeUnit unit)
        throws InterruptedException {
        if (tasks == null || unit == null)
            throw new NullPointerException();
        long nanos = unit.toNanos(timeout);
        List> futures = new ArrayList>(tasks.size());
        boolean done = false;
        try {
            for (Callable t : tasks)
                futures.add(new FutureTask(t));

            long lastTime = System.nanoTime();

            Iterator> it = futures.iterator();
            while (it.hasNext()) {
                execute((Runnable)(it.next()));
                long now = System.nanoTime();
                nanos -= now - lastTime;
                lastTime = now;
                if (nanos <= 0)
                    return futures;
            }

            for (Future f : futures) {
                if (!f.isDone()) {
                    if (nanos <= 0)
                        return futures;
                    try {
                        f.get(nanos, TimeUnit.NANOSECONDS);
                    } catch (CancellationException ignore) {
                    } catch (ExecutionException ignore) {
                    } catch (TimeoutException toe) {
                        return futures;
                    }
                    long now = System.nanoTime();
                    nanos -= now - lastTime;
                    lastTime = now;
                }
            }
            done = true;
            return futures;
        } finally {
            if (!done)
                for (Future f : futures)
                    f.cancel(true);
        }
    }

}
    
    
    
    

    




    
    
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