The difference between Gingerbread and ICS of AsyncTask's Executor

gb.java

// android.os.AsyncTask 抜粋
// Executor
private static final ThreadPoolExecutor sExecutor = new ThreadPoolExecutor(CORE_POOL_SIZE,
        MAXIMUM_POOL_SIZE, KEEP_ALIVE, TimeUnit.SECONDS, sWorkQueue, sThreadFactory);

// execute
public final AsyncTask<Params, Progress, Result> execute(Params... params) {

    // 抜粋
    sExecutor.execute(mFuture);

    return this;
}

ics.java

// android.os.AsyncTask 抜粋
// Executor
public static final Executor SERIAL_EXECUTOR = new SerialExecutor();
private static volatile Executor sDefaultExecutor = SERIAL_EXECUTOR;
private static class SerialExecutor implements Executor {
    final ArrayDeque<Runnable> mTasks = new ArrayDeque<Runnable>();
    Runnable mActive;

    public synchronized void execute(final Runnable r) {
        mTasks.offer(new Runnable() {
            public void run() {
                try {
                    r.run();
                } finally {
                    scheduleNext();
                }
            }
        });
        if (mActive == null) {
            scheduleNext();
        }
    }

    protected synchronized void scheduleNext() {
        if ((mActive = mTasks.poll()) != null) {
            THREAD_POOL_EXECUTOR.execute(mActive);
        }
    }
}

// execute
public final AsyncTask<Params, Progress, Result> execute(Params... params) {
    return executeOnExecutor(sDefaultExecutor, params);
}