Supporting a CancellationToken

[Heiko65456465]

Hi,

I had not used CancellationTokenSource yet. Now I have written a general method to support the cancellation via a CancellationToken which is passed as parameter. Unfortunately, I don't know how the caller of my method would like to handle the cancellation. Would he like my method to return only a default value in case of cancellation, e.g. null, or would he like an OperationCancelledException that I have to call CancellationToken.ThrowIfCancellationRequested().

I don't understand that you can't get this information from the CancellationToken whether to throw an exception or not. Perhaps the caller could store this information in the CancellationTokenSource. Then the following would also be conceivable in my method, if there would be such a method:

public void DoSmth(CancellationToken cancellationToken)
{
for (;
{
// ...
if (cancellationToken.CanBeCanceled && cancellationToken.IsCancellationRequested)
{
// Maybe the caller doesn't want an exception?
// cancellationToken.ThrowIfCancellationRequested();

// If the caller had the possibility to set what he wants, here would happen what he wants.
cancellationToken.TryThrowIfCancellationRequested();

// He doesn't want an exception, just null.
return null;
}
// ...
}
}


Instead, I have to support some weird things like this?

public void DoSmth(CancellationToken cancellationToken, bool throwIfCancellationRequested)
{
for (;
{
// ...
if (cancellationToken.CanBeCanceled && cancellationToken.IsCancellationRequested)
{
if (throwIfCancellationRequested)
cancellationToken.ThrowIfCancellationRequested();
else
return null;
}
// ...
}
}


Do I misunderstand something?

Best Regards,

Heiko

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