AsyncImageSharp option for load testing

tests/ImageSharp.Benchmarks/LoadResizeSave/LoadResizeSaveStressRunner.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
+using System.Collections.Generic;
 using System.Drawing;
 using System.Drawing.Drawing2D;
 using System.Drawing.Imaging;
@@ -9,6 +10,7 @@ using System.IO;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using System.Threading;
 using System.Threading.Tasks;
 using ImageMagick;
 using PhotoSauce.MagicScaler;
@@ -124,6 +126,32 @@ namespace SixLabors.ImageSharp.Benchmarks.LoadResizeSave
             new ParallelOptions { MaxDegreeOfParallelism = this.MaxDegreeOfParallelism },
             action);
 
+        public Task ForEachImageParallelAsync(Func<string, Task> action)
+        {
+            int maxDegreeOfParallelism = this.MaxDegreeOfParallelism > 0
+                ? this.MaxDegreeOfParallelism
+                : Environment.ProcessorCount;
+            int partitionSize = (int)Math.Ceiling((double)this.Images.Length / maxDegreeOfParallelism);
+
+            List<Task> tasks = new();
+            for (int i = 0; i < this.Images.Length; i += partitionSize)
+            {
+                int end = Math.Min(i + partitionSize, this.Images.Length);
+                Task task = RunPartition(i, end);
+                tasks.Add(task);
+            }
+
+            return Task.WhenAll(tasks);
+
+            Task RunPartition(int start, int end) => Task.Run(async () =>
+                {
+                    for (int i = start; i < end; i++)
+                    {
+                        await action(this.Images[i]);
+                    }
+                });
+        }
+
         private void LogImageProcessed(int width, int height)
         {
             this.LastProcessedImageSize = new Size(width, height);
@@ -197,6 +225,26 @@ namespace SixLabors.ImageSharp.Benchmarks.LoadResizeSave
             image.Save(output, this.imageSharpJpegEncoder);
         }
 
+        public async Task ImageSharpResizeAsync(string input)
+        {
+            using FileStream output = File.Open(this.OutputPath(input), FileMode.Create);
+            // Resize it to fit a 150x150 square
+            using var image = await ImageSharpImage.LoadAsync(input);
+            this.LogImageProcessed(image.Width, image.Height);
+
+            image.Mutate(i => i.Resize(new ResizeOptions
+            {
+                Size = new ImageSharpSize(this.ThumbnailSize, this.ThumbnailSize),
+                Mode = ResizeMode.Max
+            }));
+
+            // Reduce the size of the file
+            image.Metadata.ExifProfile = null;
+
+            // Save the results
+            await image.SaveAsync(output, this.imageSharpJpegEncoder);
+        }
+
         public void MagickResize(string input)
         {
             using var image = new MagickImage(input);

tests/ImageSharp.Tests.ProfilingSandbox/LoadResizeSaveParallelMemoryStress.cs

@@ -51,7 +51,7 @@ namespace SixLabors.ImageSharp.Tests.ProfilingSandbox
             Console.WriteLine($"\nEnvironment.ProcessorCount={Environment.ProcessorCount}");
             Stopwatch timer;
 
-            if (options == null || !options.ImageSharp)
+            if (options == null || !(options.ImageSharp || options.AsyncImageSharp))
             {
                 RunBenchmarkSwitcher(lrs, out timer);
             }
@@ -74,7 +74,16 @@ namespace SixLabors.ImageSharp.Tests.ProfilingSandbox
                 {
                     for (int i = 0; i < options.RepeatCount; i++)
                     {
-                        lrs.ImageSharpBenchmarkParallel();
+                        if (options.AsyncImageSharp)
+                        {
+                            lrs.ImageSharpBenchmarkParallelAsync();
+                        }
+                        else
+                        {
+                            lrs.ImageSharpBenchmarkParallel();
+                        }
+
+                        Console.WriteLine("OK");
                     }
                 }
                 catch (Exception ex)
@@ -221,6 +230,9 @@ namespace SixLabors.ImageSharp.Tests.ProfilingSandbox
 
         private class CommandLineOptions
         {
+            [Option('a', "async-imagesharp", Required = false, Default = false, HelpText = "Async ImageSharp without benchmark switching")]
+            public bool AsyncImageSharp { get; set; }
+
             [Option('i', "imagesharp", Required = false, Default = false, HelpText = "Test ImageSharp without benchmark switching")]
             public bool ImageSharp { get; set; }
 
@@ -277,7 +289,7 @@ namespace SixLabors.ImageSharp.Tests.ProfilingSandbox
             }
 
             public override string ToString() =>
-                $"p({this.MaxDegreeOfParallelism})_i({this.ImageSharp})_d({this.KeepDefaultAllocator})_m({this.MaxContiguousPoolBufferMegaBytes})_s({this.MaxPoolSizeMegaBytes})_u({this.MaxCapacityOfNonPoolBuffersMegaBytes})_r({this.RepeatCount})_g({this.GcFrequency})_e({this.ReleaseRetainedResourcesAtEnd})_l({this.LeakFrequency})";
+                $"p({this.MaxDegreeOfParallelism})_i({this.ImageSharp})_a({this.AsyncImageSharp})_d({this.KeepDefaultAllocator})_m({this.MaxContiguousPoolBufferMegaBytes})_s({this.MaxPoolSizeMegaBytes})_u({this.MaxCapacityOfNonPoolBuffersMegaBytes})_r({this.RepeatCount})_g({this.GcFrequency})_e({this.ReleaseRetainedResourcesAtEnd})_l({this.LeakFrequency})";
 
             public MemoryAllocator CreateMemoryAllocator()
             {
@@ -330,11 +342,17 @@ namespace SixLabors.ImageSharp.Tests.ProfilingSandbox
                 }
             });
 
+        private void ImageSharpBenchmarkParallelAsync() =>
+            this.Benchmarks.ForEachImageParallelAsync(f => this.Benchmarks.ImageSharpResizeAsync(f))
+                .GetAwaiter()
+                .GetResult();
+
         private void MagickBenchmarkParallel() => this.ForEachImage(this.Benchmarks.MagickResize);
 
         private void MagicScalerBenchmarkParallel() => this.ForEachImage(this.Benchmarks.MagicScalerResize);
 
         private void SkiaBitmapBenchmarkParallel() => this.ForEachImage(this.Benchmarks.SkiaBitmapResize);
+
         private void SkiaBitmapDecodeToTargetSizeBenchmarkParallel() => this.ForEachImage(this.Benchmarks.SkiaBitmapDecodeToTargetSize);
 
         private void NetVipsBenchmarkParallel() => this.ForEachImage(this.Benchmarks.NetVipsResize);