public static IReadOnlyCollection <Exception> ForEach <T>(
IEnumerable <T> items,
Action <T> handleItem,
DegreeOfParallelism?degreeOfParallelism = default,
CancellationToken cancellationToken = default)
{
var threadCount = (degreeOfParallelism ?? DegreeOfParallelism.Default).Value;
var exceptions = new ConcurrentBag <Exception>();
using var blockingItems = new BlockingCollection <T>(new ConcurrentQueue <T>());
var threads = Enumerable
.Range(0, threadCount)
.Select(index => new Thread(() =>
{
ForEachThreadLoop(
blockingItems,
handleItem,
exceptions,
cancellationToken);
})
{
Name = $"{nameof(ParallelExecution)} [{index}]",
})
.ToList();
threads.ForEach(t => t.Start());
blockingItems.AddRangeSafe(items, cancellationToken);
blockingItems.CompleteAdding();
threads.ForEach(t => t.Join());
if (cancellationToken.IsCancellationRequested)
{
exceptions.Add(new OperationCanceledException(cancellationToken));
}
return(exceptions);
}