public async Task StartAsync()
{
// ReSharper disable once MethodSupportsCancellation
await runningInstanceSemaphore.WaitAsync();
try
{
if (runningInstance != null)
{
return;
}
runningInstance = new AsyncTimerStartedInstance(cancellationToken);
#pragma warning disable 4014 // Don't await, just schedule in background
// ReSharper disable once MethodSupportsCancellation
Task.Run(() => MainLoopAsync(runningInstance));
#pragma warning restore 4014
}
finally
{
runningInstanceSemaphore.Release();
}
}
private async Task MainLoopAsync([NotNull] AsyncTimerStartedInstance currentInstance)
{
if (currentInstance == null)
{
throw new ArgumentNullException(nameof(currentInstance));
}
try
{
currentInstance.CancellationToken.ThrowIfCancellationRequested();
await Task.Delay(initialDelay, currentInstance.CancellationToken);
do
{
currentInstance.CancellationToken.ThrowIfCancellationRequested();
var actions = Elapsed
?.GetInvocationList()
.ToArray()
.Cast <AsyncTimerActionDelegate>();
if (actions == null)
{
continue;
}
var cancellationTokenCopy = currentInstance.CancellationToken;
await Task.WhenAll(actions.Select(async action =>
{
try
{
await action(cancellationTokenCopy);
}
catch (Exception exception)
{
try
{
var task = ExceptionOccurred?.Invoke(action, exception);
if (task != null)
{
await task;
}
}
catch { /* ignored */ }
}
}));
currentInstance.CancellationToken.ThrowIfCancellationRequested();
await Task.Delay(interval, currentInstance.CancellationToken);
}while (autoReset);
}
catch (TaskCanceledException) { /* expected */ }
finally
{
// ReSharper disable once MethodSupportsCancellation
await runningInstanceSemaphore.WaitAsync();
try
{
if (runningInstance == currentInstance)
{
runningInstance = null;
}
}
finally
{
runningInstanceSemaphore.Release();
}
try { currentInstance.Dispose(); } catch { /* ignored */ }
}
}
