Ejemplo n.º 1
0
        protected Timer ProcessRetriesUsingTimer(Func <bool> attempter, Action <OperationResultEventArgs> callback)
        {
            int   tryCount = 0;
            Timer timer    = null;

            TimerCallback timerCallback = (state) => {
                try {
                    OperationResultEventArgs resultArgs = null;
                    try {
                        resultArgs = TryOnce(attempter, ++tryCount, timer);
                    }
                    catch (Exception ex) {
                        resultArgs = new OperationResultEventArgs(ResultEnum.Failure, ex, tryCount);
                    }
                    if (resultArgs != null && callback != null)
                    {
                        callback(resultArgs);
                    }
                }
                // Supressing all exceptions to avoid an unhandled exception from killing the entire windows process
                catch { }
            };

            // Creating a single-time and immediate timer for the first attempt
            timer = new Timer(timerCallback, null, 0, 0);
            return(timer);
        }
Ejemplo n.º 2
0
        protected BackgroundWorker CreateBackgroundRetryWorker(Func <bool> attempter, Action <OperationResultEventArgs> callback)
        {
            var       worker   = new BackgroundWorker();
            bool      success  = false;
            int       tryCount = 0;
            Exception error    = null;

            // Creating the handler delegate, which creates another delegate itself
            worker.DoWork +=
                delegate(object sender, DoWorkEventArgs e) {
                Func <bool> callWrapper =
                    delegate {
                    if (worker.CancellationPending)
                    {
                        e.Cancel = true;     // Indicate that cancellation occured (no exception)
                        return(true);        // Returning without an exception will end the retry cycle
                    }
                    return(attempter());
                };

                success = TryAll(callWrapper, out tryCount, out error);
            };

            if (callback != null)
            {
                worker.RunWorkerCompleted += delegate(object sender, RunWorkerCompletedEventArgs args) {
                    var result =
                        args.Error != null ? ResultEnum.Failure :
                        args.Cancelled ? ResultEnum.Canceled :
                        ResultEnum.Success;
                    var resultArgs = new OperationResultEventArgs(result, args.Error ?? error, tryCount);
                    callback(resultArgs);
                };
            }

            return(worker);
        }
Ejemplo n.º 3
0
 protected abstract void NotifyAsyncCallback(OperationResultEventArgs args);