NaiveProgress

Provides a non-threaded implementation of IProgress.

The canonical implementation of IProgress is Progress, which uses a SynchronizationContext if you have one, and the thread pool if you don't. ASP.NET Core, Console and Test applications don't. The result is your progress reports might end up coming in out-of-order.

NaiveProgress doesn't do anything fancy. No SynchronizationContext, no thread pool. All reports are passed along to an event in the order they are received.

Nuget Packages

Package Name	Target Framework	Version
NaiveProgress	.NET Standard 2.0

Usage

Whenever you need an IProgress, make a NaiveProgress<T> instead of a Progress<T>; it was designed to be a drop in replacement.

Proof of Concept

Consider this function which delays for a period of time, and frequently reports progress.

private static void Delay(TimeSpan t, IProgress<TimeSpan> progress)
{
	var sw = new System.Diagnostics.Stopwatch();
	sw.Start();

	while (sw.Elapsed < t)
	{
		System.Threading.Thread.Sleep(1);
		progress.Report(sw.Elapsed);
	}
}

Using the normal Progress implementation is as follows

var progress = new Progress<TimeSpan>((e) =>
{
	Console.WriteLine(e.Ticks);
});

Delay(TimeSpan.FromMilliseconds(20), progress);

The following is the entire real output from running the above in a console application.

12618
468586
69860
117134

Ouch. As you can see, the console writes are out-of-order. Otherwise you'd expect Ticks to always increase.

To get in-order reports, simply change Progress to NaiveProgress

var progress = new NaiveProgress<TimeSpan>((e) =>
{
	Console.WriteLine(e.Ticks);
});

Delay(TimeSpan.FromMilliseconds(20), progress);

The result:

12986
62947
78007
93076
108074
123171
138230
153266
168358
183371
198416
213470

Every event is handled, and they're handled in-order.