public static async Task <T> PollAsync <T>(
Func <Task <T> > valueProvider,
Func <T, bool> shouldAcceptValue,
TimeSpan timeout,
PollingIntervalOptions interval,
CancellationToken cancellationToken)
{
T value;
var stopwatch = Stopwatch.StartNew();
var count = 0;
do
{
cancellationToken.ThrowIfCancellationRequested();
value = await valueProvider();
if (shouldAcceptValue(value) ||
stopwatch.Elapsed >= timeout)
{
break;
}
await Task.Delay(CalculateDelay(interval, count++));
} while (stopwatch.Elapsed < timeout);
return(value);
}
private static int CalculateDelay(PollingIntervalOptions interval, int count)
{
return((int)Math.Min(interval.Initial * Math.Pow(interval.Factor, count), interval.Max));
}