//fancy select
public static async Task <long> BigSumIenumerable(IEnumerable <int> delays)
{
var tasks = delays.Select(i =>
{
Task.Delay(i);
return(CompletedTask.Get().CalcSomething());
});
Task <long>[] calculations = tasks.ToArray(); //start work
long[] ret = await Task.WhenAll(calculations); //async wait for results
return(ret.Sum());
}
public static async Task <long> BigSum()
{
List <Task <long> > tasks = new List <Task <long> >();
foreach (var unused in Enumerable.Range(0, 5))
{
tasks.Add(CompletedTask.Get().CalcSomething());
}
try
{
var ret = await Task.WhenAll(tasks);
return(ret.Sum());
}
catch (Exception e)
{
//If any task throws, WhenAll faults with the Exception here
//There is no need to check exceptions from other tasks; first is enough
Console.WriteLine(e);
throw;
}
}