public static async Task ForEach <TElement>(IEnumerable <TElement> elements, Action <TElement> perform, int mdop = -1)
{
if (mdop == -1)
{
mdop = Environment.ProcessorCount * 2;
}
if (mdop < 2)
{
mdop = 2;
}
SynchronizingEnumerator <TElement> enumerator = new SynchronizingEnumerator <TElement>(elements.GetEnumerator());
Task[] waiters = new Task[mdop - 1];
HashSet <Exception> exceptions = new HashSet <Exception>();
TElement current;
while (enumerator.TryTakeNext(out current))
{
TElement localCurrent = current;
int slot = await FindFreeSlotAsync(waiters, exceptions);
waiters[slot] = Task.Run(() => perform(localCurrent));
}
try
{
await Task.WhenAll(waiters.Where(x => x != null));
}
catch (Exception ex)
{
exceptions.Add(ex);
}
if (exceptions.Count > 0)
{
throw new AggregateException(exceptions);
}
}
