From cb4511c09d9a4896ebf385528979266498ece8fc Mon Sep 17 00:00:00 2001
From: Natalia Portillo <claunia@claunia.com>
Date: Tue, 29 Jul 2025 21:36:36 +0100
Subject: [PATCH] Instruct parallel foreach to not go over the number of
 processor threads, it's counter productive.

And it should not do it by default but apparently, it does.
---
 .../Components/Dialogs/ImportRoms.razor.cs           |  8 ++++++++
 RomRepoMgr.Core/Workers/FileImporter.cs              |  8 ++++++++
 RomRepoMgr/ViewModels/ImportRomFolderViewModel.cs    | 12 ++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/RomRepoMgr.Blazor/Components/Dialogs/ImportRoms.razor.cs b/RomRepoMgr.Blazor/Components/Dialogs/ImportRoms.razor.cs
index 563949d..9e8c760 100644
--- a/RomRepoMgr.Blazor/Components/Dialogs/ImportRoms.razor.cs
+++ b/RomRepoMgr.Blazor/Components/Dialogs/ImportRoms.razor.cs
@@ -202,6 +202,10 @@ public partial class ImportRoms : ComponentBase
         _stopwatch.Restart();
 
         Parallel.ForEach(_rootImporter.Files,
+                         new ParallelOptions
+                         {
+                             MaxDegreeOfParallelism = Environment.ProcessorCount
+                         },
                          file =>
                          {
                              _ = InvokeAsync(() =>
@@ -284,6 +288,10 @@ public partial class ImportRoms : ComponentBase
 
         // For each archive
         Parallel.ForEach(_rootImporter.Archives,
+                         new ParallelOptions
+                         {
+                             MaxDegreeOfParallelism = Environment.ProcessorCount
+                         },
                          archive =>
                          {
                              _ = InvokeAsync(() =>
diff --git a/RomRepoMgr.Core/Workers/FileImporter.cs b/RomRepoMgr.Core/Workers/FileImporter.cs
index 10101b4..e9ab92f 100644
--- a/RomRepoMgr.Core/Workers/FileImporter.cs
+++ b/RomRepoMgr.Core/Workers/FileImporter.cs
@@ -99,6 +99,10 @@ public sealed class FileImporter
         ConcurrentBag<string> archives = [];
 
         Parallel.ForEach(Files,
+                         new ParallelOptions
+                         {
+                             MaxDegreeOfParallelism = Environment.ProcessorCount
+                         },
                          file =>
                          {
                              SetProgress?.Invoke(this,
@@ -170,6 +174,10 @@ public sealed class FileImporter
         ConcurrentBag<string> archives = [];
 
         Parallel.ForEach(Files,
+                         new ParallelOptions
+                         {
+                             MaxDegreeOfParallelism = Environment.ProcessorCount
+                         },
                          file =>
                          {
                              try
diff --git a/RomRepoMgr/ViewModels/ImportRomFolderViewModel.cs b/RomRepoMgr/ViewModels/ImportRomFolderViewModel.cs
index b9ad202..dec0463 100644
--- a/RomRepoMgr/ViewModels/ImportRomFolderViewModel.cs
+++ b/RomRepoMgr/ViewModels/ImportRomFolderViewModel.cs
@@ -213,6 +213,10 @@ public sealed partial class ImportRomFolderViewModel : ViewModelBase
         _stopwatch.Restart();
 
         Parallel.ForEach(_rootImporter.Files,
+                         new ParallelOptions
+                         {
+                             MaxDegreeOfParallelism = Environment.ProcessorCount
+                         },
                          file =>
                          {
                              Dispatcher.UIThread.Post(() =>
@@ -284,6 +288,10 @@ public sealed partial class ImportRomFolderViewModel : ViewModelBase
         _stopwatch.Restart();
 
         Parallel.ForEach(_rootImporter.Archives,
+                         new ParallelOptions
+                         {
+                             MaxDegreeOfParallelism = Environment.ProcessorCount
+                         },
                          archive =>
                          {
                              Dispatcher.UIThread.Post(() =>
@@ -365,6 +373,10 @@ public sealed partial class ImportRomFolderViewModel : ViewModelBase
         _stopwatch.Restart();
 
         Parallel.ForEach(_rootImporter.Archives,
+                         new ParallelOptions
+                         {
+                             MaxDegreeOfParallelism = Environment.ProcessorCount
+                         },
                          archive =>
                          {
                              Dispatcher.UIThread.Post(() =>