[browser][MT] - CancellationToken for JSWebWorker

src/libraries/System.Runtime.InteropServices.JavaScript/src/System/Runtime/InteropServices/JavaScript/Interop/JavaScriptExports.cs

@@ -279,7 +279,7 @@ public static void GetManagedStackTrace(JSMarshalerArgument* arguments_buffer)
         // void InstallMainSynchronizationContext()
         public static void InstallMainSynchronizationContext()
         {
-            InstallWebWorkerInterop(true);
+            InstallWebWorkerInterop(true, CancellationToken.None);
         }
 
 #endif

src/libraries/System.Runtime.InteropServices.JavaScript/src/System/Runtime/InteropServices/JavaScript/JSHostImplementation.cs

@@ -209,9 +209,9 @@ public static void LoadSatelliteAssembly(byte[] dllBytes)
         }
 
 #if FEATURE_WASM_THREADS
-        public static void InstallWebWorkerInterop(bool isMainThread)
+        public static JSSynchronizationContext InstallWebWorkerInterop(bool isMainThread, CancellationToken cancellationToken)
         {
-            var ctx = new JSSynchronizationContext(isMainThread);
+            var ctx = new JSSynchronizationContext(isMainThread, cancellationToken);
             ctx.previousSynchronizationContext = SynchronizationContext.Current;
             SynchronizationContext.SetSynchronizationContext(ctx);
 
@@ -226,6 +226,8 @@ public static void InstallWebWorkerInterop(bool isMainThread)
             ctx.AwaitNewData();
 
             Interop.Runtime.InstallWebWorkerInterop(proxyContext.ContextHandle);
+
+            return ctx;
         }
 
         public static void UninstallWebWorkerInterop()

src/libraries/System.Runtime.InteropServices.JavaScript/src/System/Runtime/InteropServices/JavaScript/JSProxyContext.cs

@@ -354,6 +354,7 @@ public unsafe void ReleasePromiseHolder(nint holderGCHandle)
                     {
                         throw new InvalidOperationException("ReleasePromiseHolder expected PromiseHolder " + holderGCHandle);
                     }
+                    holder.IsDisposed = true;
                 }
                 else
                 {
@@ -367,9 +368,9 @@ public unsafe void ReleasePromiseHolder(nint holderGCHandle)
                     {
                         throw new InvalidOperationException("ReleasePromiseHolder expected PromiseHolder" + holderGCHandle);
                     }
+                    holder.IsDisposed = true;
                     handle.Free();
                 }
-                holder.IsDisposed = true;
             }
         }
 

src/libraries/System.Runtime.InteropServices.JavaScript/src/System/Runtime/InteropServices/JavaScript/JSSynchronizationContext.cs

@@ -6,7 +6,6 @@
 using System.Threading;
 using System.Threading.Channels;
 using System.Runtime.CompilerServices;
-using System.Collections.Generic;
 using WorkItemQueueType = System.Threading.Channels.Channel<System.Runtime.InteropServices.JavaScript.JSSynchronizationContext.WorkItem>;
 
 namespace System.Runtime.InteropServices.JavaScript
@@ -26,6 +25,8 @@ internal sealed class JSSynchronizationContext : SynchronizationContext
 
         internal SynchronizationContext? previousSynchronizationContext;
         internal bool _isDisposed;
+        internal bool _isCancellationRequested;
+        private CancellationTokenRegistration _cancellationTokenRegistration;
 
         internal readonly struct WorkItem
         {
@@ -41,11 +42,16 @@ public WorkItem(SendOrPostCallback callback, object? data, ManualResetEventSlim?
             }
         }
 
-        public JSSynchronizationContext(bool isMainThread)
+        public JSSynchronizationContext(bool isMainThread, CancellationToken cancellationToken)
         {
             ProxyContext = new JSProxyContext(isMainThread, this);
             Queue = Channel.CreateUnbounded<WorkItem>(new UnboundedChannelOptions { SingleWriter = false, SingleReader = true, AllowSynchronousContinuations = true });
             _DataIsAvailable = DataIsAvailable;
+            _cancellationTokenRegistration = cancellationToken.Register(() =>
+            {
+                _isCancellationRequested=true;
+                Queue.Writer.TryComplete();
+            });
         }
 
         internal JSSynchronizationContext(JSProxyContext proxyContext, WorkItemQueueType queue, Action dataIsAvailable)
@@ -62,14 +68,19 @@ public override SynchronizationContext CreateCopy()
 
         internal void AwaitNewData()
         {
-            if (_isDisposed)
+            if (_isDisposed || _isCancellationRequested)
             {
                 // FIXME: there could be abandoned work, but here we have no way how to propagate the failure
                 // ObjectDisposedException.ThrowIf(_isDisposed, this);
                 return;
             }
 
             var vt = Queue.Reader.WaitToReadAsync();
+            if (_isCancellationRequested)
+            {
+                return;
+            }
+
             if (vt.IsCompleted)
             {
                 DataIsAvailable();
@@ -138,7 +149,7 @@ private static void BackgroundJobHandler()
 
         private void Pump()
         {
-            if (_isDisposed)
+            if (_isDisposed || _isCancellationRequested)
             {
                 // FIXME: there could be abandoned work, but here we have no way how to propagate the failure
                 // ObjectDisposedException.ThrowIf(_isDisposed, this);
@@ -168,7 +179,7 @@ private void Pump()
             finally
             {
                 // If an item throws, we want to ensure that the next pump gets scheduled appropriately regardless.
-                if (!_isDisposed) AwaitNewData();
+                if (!_isDisposed && !_isCancellationRequested) AwaitNewData();
             }
         }
 

src/libraries/System.Runtime.InteropServices.JavaScript/src/System/Runtime/InteropServices/JavaScript/JSWebWorker.cs

@@ -54,8 +54,9 @@ private static Task<T> RunAsyncImpl<T>(Func<Task<T>> body, CancellationToken can
             // continuation should not be running synchronously in the JSWebWorker thread because we are about to kill it after we resolve/reject the Task.
             var tcs = new TaskCompletionSource<T>(TaskCreationOptions.RunContinuationsAsynchronously);
             var capturedContext = SynchronizationContext.Current;
-            var t = new Thread(() =>
+            var thread = new Thread(() =>
             {
+                CancellationTokenRegistration? reg = null;
                 try
                 {
                     if (cancellationToken.IsCancellationRequested)
@@ -64,7 +65,17 @@ private static Task<T> RunAsyncImpl<T>(Func<Task<T>> body, CancellationToken can
                         return;
                     }
 
-                    JSHostImplementation.InstallWebWorkerInterop(false);
+                    var synchronizationContext = JSHostImplementation.InstallWebWorkerInterop(false, cancellationToken);
+
+                    reg = cancellationToken.Register(() =>
+                    {
+                        synchronizationContext.Send(static o =>
+                        {
+                            JSHostImplementation.UninstallWebWorkerInterop();
+                        }, synchronizationContext);
+                        SendWhenException(parentContext, tcs, new OperationCanceledException(cancellationToken));
+                    });
+
                     var childScheduler = TaskScheduler.FromCurrentSynchronizationContext();
                     Task<T> res = body();
                     // This code is exiting thread main() before all promises are resolved.
@@ -73,16 +84,18 @@ private static Task<T> RunAsyncImpl<T>(Func<Task<T>> body, CancellationToken can
                     {
                         SendWhenDone(parentContext, tcs, res);
                         JSHostImplementation.UninstallWebWorkerInterop();
+                        reg?.Dispose();
                     }, childScheduler);
                 }
                 catch (Exception ex)
                 {
                     SendWhenException(parentContext, tcs, ex);
+                    JSHostImplementation.UninstallWebWorkerInterop();
+                    reg?.Dispose();
                 }
-
             });
-            JSHostImplementation.SetHasExternalEventLoop(t);
-            t.Start();
+            JSHostImplementation.SetHasExternalEventLoop(thread);
+            thread.Start();
             return tcs.Task;
         }
 
@@ -92,8 +105,9 @@ private static Task RunAsyncImpl(Func<Task> body, CancellationToken cancellation
             // continuation should not be running synchronously in the JSWebWorker thread because we are about to kill it after we resolve/reject the Task.
             var tcs = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
             var capturedContext = SynchronizationContext.Current;
-            var t = new Thread(() =>
+            var thread = new Thread(() =>
             {
+                CancellationTokenRegistration? reg = null;
                 try
                 {
                     if (cancellationToken.IsCancellationRequested)
@@ -102,7 +116,17 @@ private static Task RunAsyncImpl(Func<Task> body, CancellationToken cancellation
                         return;
                     }
 
-                    JSHostImplementation.InstallWebWorkerInterop(false);
+                    var synchronizationContext = JSHostImplementation.InstallWebWorkerInterop(false, cancellationToken);
+
+                    reg = cancellationToken.Register(() =>
+                    {
+                        synchronizationContext.Send(static o =>
+                        {
+                            JSHostImplementation.UninstallWebWorkerInterop();
+                        }, synchronizationContext);
+                        SendWhenException(parentContext, tcs, new OperationCanceledException(cancellationToken));
+                    });
+
                     var childScheduler = TaskScheduler.FromCurrentSynchronizationContext();
                     Task res = body();
                     // This code is exiting thread main() before all promises are resolved.
@@ -111,16 +135,19 @@ private static Task RunAsyncImpl(Func<Task> body, CancellationToken cancellation
                     {
                         SendWhenDone(parentContext, tcs, res);
                         JSHostImplementation.UninstallWebWorkerInterop();
+                        reg?.Dispose();
                     }, childScheduler);
                 }
                 catch (Exception ex)
                 {
                     SendWhenException(parentContext, tcs, ex);
+                    reg?.Dispose();
+                    JSHostImplementation.UninstallWebWorkerInterop();
                 }
 
             });
-            JSHostImplementation.SetHasExternalEventLoop(t);
-            t.Start();
+            JSHostImplementation.SetHasExternalEventLoop(thread);
+            thread.Start();
             return tcs.Task;
         }
 

src/libraries/System.Runtime.InteropServices.JavaScript/tests/System.Runtime.InteropServices.JavaScript.UnitTests/System.Runtime.InteropServices.JavaScript.Tests.csproj

@@ -14,6 +14,11 @@
     <!-- Use following lines to write the generated files to disk. -->
     <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
   </PropertyGroup>
+  <!-- Make debugging easier -->
+  <PropertyGroup Condition="'$(Configuration)' == 'Debug'">
+    <WasmNativeStrip >false</WasmNativeStrip>
+    <WasmXHarnessMonoArgs>$(WasmXHarnessMonoArgs) --setenv=XHARNESS_LOG_TEST_START=true</WasmXHarnessMonoArgs>
+  </PropertyGroup>
   <ItemGroup>
     <Compile Include="System\Runtime\InteropServices\JavaScript\JavaScriptTestHelper.cs" />
     <Compile Include="System\Runtime\InteropServices\JavaScript\JSImportExportTest.cs" />