Как я открываю Google Maps для направлений с помощью координат на iPhone

Вот то, что я придумал ... также см. Ответ Сэма Шафрана. Этот ответ - вики сообщества, если есть какие-то проблемы, которые люди видят в коде и хотят обновить.

/// <summary>
/// A singleton queue that manages writing log entries to the different logging sources (Enterprise Library Logging) off the executing thread.
/// This queue ensures that log entries are written in the order that they were executed and that logging is only utilizing one thread (backgroundworker) at any given time.
/// </summary>
public class AsyncLoggerQueue
{
    //create singleton instance of logger queue
    public static AsyncLoggerQueue Current = new AsyncLoggerQueue();

    private static readonly object logEntryQueueLock = new object();

    private Queue<LogEntry> _LogEntryQueue = new Queue<LogEntry>();
    private BackgroundWorker _Logger = new BackgroundWorker();

    private AsyncLoggerQueue()
    {
        //configure background worker
        _Logger.WorkerSupportsCancellation = false;
        _Logger.DoWork += new DoWorkEventHandler(_Logger_DoWork);
    }

    public void Enqueue(LogEntry le)
    {
        //lock during write
        lock (logEntryQueueLock)
        {
            _LogEntryQueue.Enqueue(le);

            //while locked check to see if the BW is running, if not start it
            if (!_Logger.IsBusy)
                _Logger.RunWorkerAsync();
        }
    }

    private void _Logger_DoWork(object sender, DoWorkEventArgs e)
    {
        while (true)
        {
            LogEntry le = null;

            bool skipEmptyCheck = false;
            lock (logEntryQueueLock)
            {
                if (_LogEntryQueue.Count <= 0) //if queue is empty than BW is done
                    return;
                else if (_LogEntryQueue.Count > 1) //if greater than 1 we can skip checking to see if anything has been enqueued during the logging operation
                    skipEmptyCheck = true;

                //dequeue the LogEntry that will be written to the log
                le = _LogEntryQueue.Dequeue();
            }

            //pass LogEntry to Enterprise Library
            Logger.Write(le);

            if (skipEmptyCheck) //if LogEntryQueue.Count was > 1 before we wrote the last LogEntry we know to continue without double checking
            {
                lock (logEntryQueueLock)
                {
                    if (_LogEntryQueue.Count <= 0) //if queue is still empty than BW is done
                        return;
                }
            }
        }
    }
}