The Power of Task.WhenEach in .NET 9

Asynchronous programming in .NET has always been a powerful tool for building efficient and responsive applications. With the introduction of .NET 9, a new method called Task.WhenEach has been added to the arsenal of asynchronous programming tools. This method addresses the limitations of existing methods like Task.WhenAll and Task.WhenAny, providing immediate processing of completed tasks and enhancing performance and scalability.

Let’s take a look at how Task.WhenEach can be used in your code:

using var tokenSource = new CancellationTokenSource(10_000);
var token = tokenSource.Token;
await foreach (var data in Task.WhenEach(tasks).WithCancellation(token))
{
    if (!tokenSource.TryReset()) 
        token.ThrowIfCancellationRequested();
    Console.WriteLine(await data);
    tokenSource.CancelAfter(10_000);
}

In the code snippet above, CancellationTokenSource is used to create instances of a CancellationToken, allowing for easy cancellation of tasks. The ThrowIfCancellationRequested method throws an OperationCanceledException when cancellation is requested, while the CancelAfter method schedules a cancellation operation after a specified delay.

Key takeaways

Here are some key points to remember about Task.WhenEach:

• The Task.WhenEach method in .NET 9 offers immediate processing of completed tasks, improving the performance and scalability of your applications.
• Calling ThrowIfCancellationRequested within a task allows for easy cancellation handling without the need to explicitly catch exceptions.
• When ThrowIfCancellationRequested is called within a task, the execution leaves the current task and sets the Task.IsCancelled property to True.

Overall, Task.WhenEach is a valuable addition to the asynchronous programming capabilities of .NET 9, providing developers with more flexibility and efficiency in handling asynchronous tasks. Make sure to leverage this powerful method in your next project to unlock its full potential.