private IScheduledTask ScheduleInternal(TimeSpan initialDelay, TimeSpan period,
Func <CancellationToken, Task> action, Func <IFailureContext, CancellationToken, Task> onException,
TimeSpan maxBackoffPeriod)
{
SchedulerAssertions.Assert(initialDelay, period, action, onException, maxBackoffPeriod);
var cancellationTokenSource = new CancellationTokenSource();
var cancellationToken = cancellationTokenSource.Token;
var task = Task.Run(async() =>
{
using (cancellationTokenSource)
{
var failureContext = new FailureContext(period, maxBackoffPeriod, () => Now);
if (initialDelay > TimeSpan.Zero)
{
await Task.Delay(initialDelay, cancellationToken);
await CallAction(action, onException, cancellationToken, failureContext);
}
while (!cancellationToken.IsCancellationRequested)
{
await Task.Delay(failureContext.CurrentPeriod, cancellationToken);
await CallAction(action, onException, cancellationToken, failureContext);
}
}
}, cancellationToken);
return(new ScheduledTask(task, cancellationTokenSource));
}
public TestScheduledTask(DateTimeOffset dueTime, TimeSpan period, Func <CancellationToken, Task> action,
Func <IFailureContext, CancellationToken, Task> onException, TimeSpan maxBackoffPeriod,
Func <DateTimeOffset> currentDateTime)
{
OnException = onException;
Action = action;
DueTime = dueTime;
FailureContext = new FailureContext(period, maxBackoffPeriod, currentDateTime);
}
private static async Task CallAction(Func <CancellationToken, Task> action,
Func <IFailureContext, CancellationToken, Task> onException, CancellationToken cancellationToken,
FailureContext failureContext)
{
try
{
await action(cancellationToken);
failureContext.Reset();
}
catch (Exception e)
{
try
{
failureContext.SetException(e);
await onException(failureContext, cancellationToken);
}
catch
{
// dont do anything if we failed to log
}
}
}