From 7aa064d0e366ed0b5b87e56f59372595fa08b35d Mon Sep 17 00:00:00 2001
From: Jerome Laban <jerome.laban@nventive.com>
Date: Thu, 8 Dec 2022 08:55:51 -0500
Subject: [PATCH] fix(dispatcherqueue): Use proper
 `CheckThreadAccess`/`HasThreadAccess` behavior

---
 .../Core/CoreDispatcher.wasm.cs                 |  2 +-
 src/Uno.UI/UI/Xaml/DragDrop/DragDropManager.cs  |  2 +-
 src/Uno.UWP/System/DispatcherQueue.cs           | 17 +++++------------
 src/Uno.UWP/UI/Core/CoreDispatcher.wasm.cs      |  2 --
 4 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/src/Uno.UI.Dispatching/Core/CoreDispatcher.wasm.cs b/src/Uno.UI.Dispatching/Core/CoreDispatcher.wasm.cs
index 3f64457110d9..3803f4fba383 100644
--- a/src/Uno.UI.Dispatching/Core/CoreDispatcher.wasm.cs
+++ b/src/Uno.UI.Dispatching/Core/CoreDispatcher.wasm.cs
@@ -13,7 +13,7 @@ namespace Uno.UI.Dispatching
 {
 	internal sealed partial class CoreDispatcher
 	{
-		internal bool IsThreadingSupported { get; }
+		internal static bool IsThreadingSupported { get; }
 			= Environment.GetEnvironmentVariable("UNO_BOOTSTRAP_MONO_RUNTIME_FEATURES")
 				?.Split(',').Any(v => v.Equals("threads", StringComparison.OrdinalIgnoreCase)) ?? false;
 
diff --git a/src/Uno.UI/UI/Xaml/DragDrop/DragDropManager.cs b/src/Uno.UI/UI/Xaml/DragDrop/DragDropManager.cs
index f43be0a077fb..d89cf4b9a924 100644
--- a/src/Uno.UI/UI/Xaml/DragDrop/DragDropManager.cs
+++ b/src/Uno.UI/UI/Xaml/DragDrop/DragDropManager.cs
@@ -43,7 +43,7 @@ public void BeginDragAndDrop(CoreDragInfo info, ICoreDropOperationTarget? target
 		{
 			if (
 #if __WASM__
-				_window.Dispatcher.IsThreadingSupported &&
+				Uno.UI.Dispatching.CoreDispatcher.IsThreadingSupported &&
 #endif
 				!_window.Dispatcher.HasThreadAccess)
 			{
diff --git a/src/Uno.UWP/System/DispatcherQueue.cs b/src/Uno.UWP/System/DispatcherQueue.cs
index 9f45322cd4ef..bbc4205b35cc 100644
--- a/src/Uno.UWP/System/DispatcherQueue.cs
+++ b/src/Uno.UWP/System/DispatcherQueue.cs
@@ -23,13 +23,15 @@ public static DispatcherQueue GetForCurrentThread()
 		{
 			if (_current == null) // Do not even check for thread access if we already have a value!
 			{
-#if !__WASM__
 				// This check is disabled on WASM until threading support is enabled, since HasThreadAccess is currently user-configured (and defaults to false).
-				if (!CoreDispatcher.Main.HasThreadAccess)
+				if (
+#if __WASM__
+					CoreDispatcher.IsThreadingSupported &&
+#endif
+					!CoreDispatcher.Main.HasThreadAccess)
 				{
 					return default;
 				}
-#endif
 
 				_current = new DispatcherQueue();
 			}
@@ -42,13 +44,10 @@ public static DispatcherQueue GetForCurrentThread()
 		/// </summary>
 		internal static void CheckThreadAccess()
 		{
-#if !__WASM__
-			// This check is disabled on WASM until threading support is enabled, since HasThreadAccess is currently user-configured (and defaults to false).
 			if (!CoreDispatcher.Main.HasThreadAccess)
 			{
 				throw new InvalidOperationException("The application called an interface that was marshalled for a different thread.");
 			}
-#endif
 		}
 
 		public bool TryEnqueue(DispatcherQueueHandler callback)
@@ -70,12 +69,6 @@ public bool TryEnqueue(DispatcherQueuePriority priority, DispatcherQueueHandler
 		}
 
 		public bool HasThreadAccess
-#if !__WASM__
 			=> CoreDispatcher.Main.HasThreadAccess;
-#else
-			// This check is disabled on WASM until threading support is enabled, since HasThreadAccess is currently user-configured (and defaults to false).
-			=> true;
-#endif
-
 	}
 }
diff --git a/src/Uno.UWP/UI/Core/CoreDispatcher.wasm.cs b/src/Uno.UWP/UI/Core/CoreDispatcher.wasm.cs
index 836d8b103924..f4f2106346b8 100644
--- a/src/Uno.UWP/UI/Core/CoreDispatcher.wasm.cs
+++ b/src/Uno.UWP/UI/Core/CoreDispatcher.wasm.cs
@@ -11,8 +11,6 @@ namespace Windows.UI.Core
 {
 	public sealed partial class CoreDispatcher
 	{
-		internal bool IsThreadingSupported { get; } = Environment.GetEnvironmentVariable("UNO_BOOTSTRAP_MONO_RUNTIME_CONFIGURATION").StartsWith("threads", StringComparison.OrdinalIgnoreCase);
-
 		/// <summary>
 		/// Provide a action that will delegate the dispatch of CoreDispatcher work
 		/// </summary>