Dispatch Mono [JSExport] by handle

src/libraries/Common/src/Interop/Browser/Interop.Runtime.CoreCLR.cs

@@ -33,11 +33,6 @@ internal static unsafe partial class Runtime
         [LibraryImport(Libraries.JavaScriptNative, EntryPoint = "SystemInteropJS_CancelPromise")]
         public static partial void CancelPromise(nint gcHandle);
 
-        [LibraryImport(Libraries.JavaScriptNative, EntryPoint = "SystemInteropJS_BindAssemblyExports")]
-        public static partial void BindAssemblyExports(IntPtr assemblyNamePtr);
-        [LibraryImport(Libraries.JavaScriptNative, EntryPoint = "SystemInteropJS_GetAssemblyExport")]
-        public static partial void GetAssemblyExport(IntPtr assemblyNamePtr, IntPtr namespacePtr, IntPtr classnamePtr, IntPtr methodNamePtr, int signatureHash, IntPtr* methodHandlePtr);
-
         // TODO-WASM: delete once we switch to CoreCLR only
         [LibraryImport(Libraries.JavaScriptNative, EntryPoint = "SystemInteropJS_AssemblyGetEntryPoint")]
         public static partial void AssemblyGetEntryPoint(IntPtr assemblyNamePtr, int auto_insert_breakpoint, void** monoMethodPtrPtr);

src/libraries/Common/src/Interop/Browser/Interop.Runtime.Mono.cs

@@ -68,7 +68,5 @@ internal static unsafe partial class Runtime
         public static extern void AssemblyGetEntryPoint(IntPtr assemblyNamePtr, int auto_insert_breakpoint, void** monoMethodPtrPtr);
         [MethodImpl(MethodImplOptions.InternalCall)]
         public static extern void BindAssemblyExports(IntPtr assemblyNamePtr);
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        public static extern void GetAssemblyExport(IntPtr assemblyNamePtr, IntPtr namespacePtr, IntPtr classnamePtr, IntPtr methodNamePtr, int signatureHash, IntPtr* monoMethodPtrPtr);
     }
 }

src/libraries/System.Runtime.InteropServices.JavaScript/src/System.Runtime.InteropServices.JavaScript.csproj

@@ -41,6 +41,7 @@
     <Compile Include="System\Runtime\InteropServices\JavaScript\JSType.cs" />
     <Compile Include="System\Runtime\InteropServices\JavaScript\JSFunctionBinding.cs" />
     <Compile Include="System\Runtime\InteropServices\JavaScript\JSHostImplementation.cs" />
+    <Compile Include="System\Runtime\InteropServices\JavaScript\JSHostImplementation.Exports.cs" />
     <Compile Include="System\Runtime\InteropServices\JavaScript\JSHostImplementation.Mono.cs" Condition="'$(RuntimeFlavor)' == 'Mono'" />
     <Compile Include="System\Runtime\InteropServices\JavaScript\JSHostImplementation.CoreCLR.cs" Condition="'$(RuntimeFlavor)' == 'CoreCLR'" />
     <Compile Include="System\Runtime\InteropServices\JavaScript\JSHostImplementation.Types.cs" />

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

@@ -151,7 +151,7 @@ public static void CallJSExport(int methodHandle, JSMarshalerArgument* arguments
         {
             ref JSMarshalerArgument argException = ref argumentsBuffer[0]; // initialized by caller in alloc_stack_frame()
             var ctx = argException.AssertCurrentThreadContext();
-            if (!ctx.JSExportByHandle.TryGetValue(methodHandle, out var jsExport))
+            if (!ctx.TryGetJSExport(methodHandle, out var jsExport))
             {
                 argException.ToJS(new InvalidOperationException("Unable to resolve JSExport by handle"));
                 return;

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

@@ -365,6 +365,19 @@ public static void BindAssemblyExports(JSMarshalerArgument* arguments_buffer)
             }
         }
 
+        // the arguments are passed positionally by mono_wasm_invoke_jsexport_by_handle, not as a marshaled frame
+        public static void CallJSExport(int methodHandle, JSMarshalerArgument* argumentsBuffer)
+        {
+            ref JSMarshalerArgument argException = ref argumentsBuffer[0]; // initialized by caller in alloc_stack_frame()
+            var ctx = argException.AssertCurrentThreadContext();
+            if (!ctx.TryGetJSExport(methodHandle, out var jsExport))
+            {
+                argException.ToJS(new InvalidOperationException("Unable to resolve JSExport by handle"));
+                return;
+            }
+            jsExport(new IntPtr(argumentsBuffer));
+        }
+
         [MethodImpl(MethodImplOptions.NoInlining)] // profiler needs to find it executed under this name
         public static void StopProfile()
         {

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

@@ -33,50 +33,5 @@ public static Task BindAssemblyExports(string? assemblyName)
             registerMethod.Invoke(null, null);
             return Task.CompletedTask;
         }
-
-        // this reflection based approach is used by JSExport assemblies generated by Net10 or below
-        [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "It's kept from trimming by DynamicDependencyAttribute in the generated code.")]
-        [UnconditionalSuppressMessage("Trimming", "IL2075", Justification = "It's kept from trimming by DynamicDependencyAttribute in the generated code.")]
-        public static unsafe JSFunctionBinding BindManagedFunction(string fullyQualifiedName, int signatureHash, ReadOnlySpan<JSMarshalerType> signatures)
-        {
-            var ctx = JSProxyContext.CurrentThreadContext;
-            var (assemblyName, nameSpace, shortClassName, methodName) = ParseFQN(fullyQualifiedName);
-            var wrapperName = $"__Wrapper_{methodName}_{signatureHash}";
-            shortClassName = shortClassName.Replace('/', '+');
-
-            // get MethodInfo from the fully qualified name
-            var assembly = Assembly.Load(new AssemblyName(assemblyName));
-            var clazz = string.IsNullOrEmpty(nameSpace)
-                ? assembly.GetType(shortClassName)
-                : assembly.GetType(nameSpace + "." + shortClassName);
-            if (clazz == null)
-            {
-                Environment.FailFast($"Can't find {nameSpace}{shortClassName} in {assemblyName} assembly");
-            }
-            var wrapperInfo = clazz.GetMethod(wrapperName, BindingFlags.Static | BindingFlags.NonPublic);
-            if (wrapperInfo == null)
-            {
-                Environment.FailFast($"Can't find method wrapper {wrapperName} in {nameSpace}.{shortClassName} in {assemblyName} assembly");
-            }
-
-            Action<IntPtr> wrapper = (IntPtr args) =>
-            {
-                object boxedLegacyArgs = Pointer.Box((void*)args, typeof(JSMarshalerArgument*));
-                // real signature is void (JSMarshalerArgument* args)
-                wrapperInfo.Invoke(null, new object?[] { boxedLegacyArgs });
-            };
-
-            int methodHandle = ctx.NextJSExportHandle++;
-            ctx.JSExportByHandle[methodHandle] = wrapper;
-
-            var signature = GetMethodSignature(signatures, null, null);
-
-            // this will hit JS side possibly on another thread, depending on JSProxyContext.CurrentThreadContext
-            JavaScriptImports.BindCSFunction(methodHandle, assemblyName, nameSpace, shortClassName, methodName, signatureHash, (IntPtr)signature.Header);
-
-            FreeMethodSignatureBuffer(signature);
-
-            return signature;
-        }
     }
 }

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

@@ -0,0 +1,55 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics.CodeAnalysis;
+using System.Reflection;
+
+namespace System.Runtime.InteropServices.JavaScript
+{
+    internal static partial class JSHostImplementation
+    {
+        [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "It's kept from trimming by DynamicDependencyAttribute in the generated code.")]
+        [UnconditionalSuppressMessage("Trimming", "IL2075", Justification = "It's kept from trimming by DynamicDependencyAttribute in the generated code.")]
+        public static unsafe JSFunctionBinding BindManagedFunction(string fullyQualifiedName, int signatureHash, ReadOnlySpan<JSMarshalerType> signatures)
+        {
+            var ctx = JSProxyContext.BindingContextOrMain();
+            var (assemblyName, nameSpace, shortClassName, methodName) = ParseFQN(fullyQualifiedName);
+            var wrapperName = $"__Wrapper_{methodName}_{signatureHash}";
+            // reflection wants '+' between nested types, but the JS side walks the export tree on '/', so keep shortClassName as parsed
+            var reflectionClassName = shortClassName.Replace('/', '+');
+
+            // get MethodInfo from the fully qualified name
+            var assembly = Assembly.Load(new AssemblyName(assemblyName));
+            var clazz = string.IsNullOrEmpty(nameSpace)
+                ? assembly.GetType(reflectionClassName)
+                : assembly.GetType(nameSpace + "." + reflectionClassName);
+            if (clazz == null)
+            {
+                Environment.FailFast($"Can't find {nameSpace}{shortClassName} in {assemblyName} assembly");
+            }
+            var wrapperInfo = clazz.GetMethod(wrapperName, BindingFlags.Static | BindingFlags.NonPublic);
+            if (wrapperInfo == null)
+            {
+                Environment.FailFast($"Can't find method wrapper {wrapperName} in {nameSpace}.{shortClassName} in {assemblyName} assembly");
+            }
+
+            Action<IntPtr> wrapper = (IntPtr args) =>
+            {
+                object boxedLegacyArgs = Pointer.Box((void*)args, typeof(JSMarshalerArgument*));
+                // real signature is void (JSMarshalerArgument* args)
+                wrapperInfo.Invoke(null, new object?[] { boxedLegacyArgs });
+            };
+
+            int methodHandle = ctx.AllocJSExportHandle(wrapper);
+
+            var signature = GetMethodSignature(signatures, null, null);
+
+            // this will hit JS side possibly on another thread, depending on JSProxyContext.CurrentThreadContext
+            JavaScriptImports.BindCSFunction(methodHandle, assemblyName, nameSpace, shortClassName, methodName, signatureHash, (IntPtr)signature.Header);
+
+            FreeMethodSignatureBuffer(signature);
+
+            return signature;
+        }
+    }
+}

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

@@ -18,38 +18,5 @@ public static Task BindAssemblyExports(string? assemblyName)
             Interop.Runtime.BindAssemblyExports(Marshal.StringToCoTaskMemUTF8(assemblyName));
             return Task.CompletedTask;
         }
-
-        public static unsafe JSFunctionBinding BindManagedFunction(string fullyQualifiedName, int signatureHash, ReadOnlySpan<JSMarshalerType> signatures)
-        {
-            var (assemblyName, nameSpace, shortClassName, methodName) = ParseFQN(fullyQualifiedName);
-
-            IntPtr monoMethod;
-            Interop.Runtime.GetAssemblyExport(
-                // FIXME: Pass UTF-16 through directly so C can work with it, doing the conversion
-                //  in C# pulls in a bunch of dependencies we don't need this early in startup.
-                // I tested removing the UTF8 conversion from this specific call, but other parts
-                //  of startup I can't identify still pull in UTF16->UTF8 conversion, so it's not
-                //  worth it to do that yet.
-                Marshal.StringToCoTaskMemUTF8(assemblyName),
-                Marshal.StringToCoTaskMemUTF8(nameSpace),
-                Marshal.StringToCoTaskMemUTF8(shortClassName),
-                Marshal.StringToCoTaskMemUTF8(methodName),
-                signatureHash,
-                &monoMethod);
-
-            if (monoMethod == IntPtr.Zero)
-            {
-                Environment.FailFast($"Can't find {nameSpace}{shortClassName}{methodName} in {assemblyName}.dll");
-            }
-
-            var signature = GetMethodSignature(signatures, null, null);
-
-            // this will hit JS side possibly on another thread, depending on JSProxyContext.CurrentThreadContext
-            JavaScriptImports.BindCSFunction(monoMethod, assemblyName, nameSpace, shortClassName, methodName, signatureHash, (IntPtr)signature.Header);
-
-            FreeMethodSignatureBuffer(signature);
-
-            return signature;
-        }
     }
 }

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

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using System.Threading;
 using static System.Runtime.InteropServices.JavaScript.JSHostImplementation;
@@ -23,8 +24,10 @@ internal sealed class JSProxyContext : IDisposable
         // they have negative values, so that they don't collide with JSHandles.
         private nint NextJSVHandle = -2;
         private readonly List<nint> JSVHandleFreeList = new();
-        internal Dictionary<int, Action<IntPtr>> JSExportByHandle = new Dictionary<int, Action<IntPtr>>();
-        internal int NextJSExportHandle = 1;
+        // Guarded by lock (this) in the multi-threaded build: BindManagedFunction can register an export
+        // into another thread's context via BindingContextOrMain, concurrently with CallJSExport reading it.
+        private readonly Dictionary<int, Action<IntPtr>> JSExportByHandle = new Dictionary<int, Action<IntPtr>>();
+        private int NextJSExportHandle = 1;
 
         public int PromiseHolderCount
         {
@@ -274,6 +277,42 @@ public static JSProxyContext AssertIsInteropThread()
 #endif
         }
 
+        // Selects the context to bind a [JSExport] into. BindManagedFunction can be reached from an
+        // assembly module initializer running on a thread without JS interop (see the documented
+        // contract on JSFunctionBinding.BindManagedFunction), so fall back to the main/UI thread
+        // context rather than rejecting that supported path.
+        public static JSProxyContext BindingContextOrMain()
+        {
+#if FEATURE_WASM_MANAGED_THREADS
+            return CurrentThreadContext ?? MainThreadContext;
+#else
+            return MainThreadContext;
+#endif
+        }
+
+        // Registration can run on a thread other than the one owning this context, see BindingContextOrMain.
+        public int AllocJSExportHandle(Action<IntPtr> wrapper)
+        {
+#if FEATURE_WASM_MANAGED_THREADS
+            lock (this)
+#endif
+            {
+                int methodHandle = NextJSExportHandle++;
+                JSExportByHandle[methodHandle] = wrapper;
+                return methodHandle;
+            }
+        }
+
+        public bool TryGetJSExport(int methodHandle, [MaybeNullWhen(false)] out Action<IntPtr> wrapper)
+        {
+#if FEATURE_WASM_MANAGED_THREADS
+            lock (this)
+#endif
+            {
+                return JSExportByHandle.TryGetValue(methodHandle, out wrapper);
+            }
+        }
+
         #endregion
 
         #region Handles

src/mono/browser/runtime/corebindings.c

@@ -36,7 +36,6 @@ typedef int (*ds_job_cb)(void* data);
 
 void SystemInteropJS_BindAssemblyExports (char *assembly_name);
 void SystemInteropJS_AssemblyGetEntryPoint (char *assembly_name, int auto_insert_breakpoint, MonoMethod **method_out);
-void SystemInteropJS_GetAssemblyExport (char *assembly_name, char *namespace, char *classname, char *methodname, int signature_hash, MonoMethod **method_out);
 
 #ifndef DISABLE_THREADS
 void SystemInteropJS_ReleaseCSOwnedObjectPost (pthread_t target_tid, int js_handle);
@@ -91,7 +90,6 @@ void bindings_initialize_internals (void)
 	mono_add_internal_call ("Interop/Runtime::CancelPromise", SystemInteropJS_CancelPromise);
 	mono_add_internal_call ("Interop/Runtime::AssemblyGetEntryPoint", SystemInteropJS_AssemblyGetEntryPoint);
 	mono_add_internal_call ("Interop/Runtime::BindAssemblyExports", SystemInteropJS_BindAssemblyExports);
-	mono_add_internal_call ("Interop/Runtime::GetAssemblyExport", SystemInteropJS_GetAssemblyExport);
 	mono_add_internal_call ("System.ConsolePal::Clear", SystemJS_ConsoleClear);
 
 	// JS-based globalization
@@ -215,38 +213,6 @@ void SystemInteropJS_BindAssemblyExports (char *assembly_name)
 	}
 }
 
-void SystemInteropJS_GetAssemblyExport (char *assembly_name, char *namespace, char *classname, char *methodname, int signature_hash, MonoMethod **method_out)
-{
-	MonoError error;
-	MonoAssembly* assembly;
-	MonoImage *image;
-	MonoClass *klass;
-	MonoMethod *method=NULL;
-    char real_method_name_buffer[4096];
-	*method_out = NULL;
-
-	assert (assembly_name);
-	assembly = _mono_wasm_assembly_load (assembly_name);
-	assert (assembly);
-	image = mono_assembly_get_image (assembly);
-	assert (image);
-
-	klass = mono_class_from_name (image, namespace, classname);
-	assert (klass);
-
-    snprintf(real_method_name_buffer, 4096, "__Wrapper_%s_%d", methodname, signature_hash);
-
-	method = mono_class_get_method_from_name (klass, real_method_name_buffer, -1);
-	assert (method);
-
-	*method_out = method;
-    // This is freed by _mono_wasm_assembly_load for some reason
-    // free (assembly_name);
-	free (namespace);
-	free (classname);
-	free (methodname);
-}
-
 #ifndef DISABLE_THREADS
 
 void* before_sync_js_import;

src/mono/browser/runtime/cwraps.ts

@@ -6,7 +6,7 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import type {
     MonoAssembly, MonoClass,
     MonoMethod, MonoObject,
-    MonoType, MonoObjectRef, MonoStringRef, JSMarshalerArguments, PThreadPtr
+    MonoType, MonoObjectRef, MonoStringRef, JSMarshalerArguments, PThreadPtr, CSFnHandle
 } from "./types/internal";
 import type { VoidPtr, CharPtrPtr, Int32Ptr, CharPtr, ManagedPointer } from "./types/emscripten";
 import { Module, runtimeHelpers } from "./globals";
@@ -20,6 +20,9 @@ const threading_cwraps: SigLine[] = WasmEnableThreads ? [
     [false, "mono_wasm_invoke_jsexport_async_post", "void", ["number", "number", "number"]],
     [false, "mono_wasm_invoke_jsexport_sync_send", "void", ["number", "number", "number"]],
     [false, "mono_wasm_invoke_jsexport_sync", "void", ["number", "number"]],
+    [false, "mono_wasm_invoke_jsexport_by_handle_async_post", "void", ["number", "number", "number"]],
+    [false, "mono_wasm_invoke_jsexport_by_handle_sync_send", "void", ["number", "number", "number"]],
+    [false, "mono_wasm_invoke_jsexport_by_handle_sync", "void", ["number", "number"]],
     [true, "mono_wasm_create_deputy_thread", "number", []],
     [true, "mono_wasm_create_io_thread", "number", []],
     [true, "mono_wasm_register_ui_thread", "void", []],
@@ -65,6 +68,8 @@ const fn_signatures: SigLine[] = [
     [() => !runtimeHelpers.emscriptenBuildOptions.enableLogProfiler, "mono_wasm_profiler_init_log", "void", ["string"]],
     [false, "mono_wasm_exec_regression", "number", ["number", "string"]],
     [false, "mono_wasm_invoke_jsexport", "void", ["number", "number"]],
+    [false, "mono_wasm_set_jsexport_dispatcher", "void", ["number"]],
+    [false, "mono_wasm_invoke_jsexport_by_handle", "void", ["number", "number"]],
     [true, "mono_wasm_write_managed_pointer_unsafe", "void", ["number", "number"]],
     [true, "mono_wasm_copy_managed_pointer", "void", ["number", "number"]],
     [true, "mono_wasm_i52_to_f64", "number", ["number", "number"]],
@@ -143,6 +148,9 @@ export interface t_ThreadingCwraps {
     mono_wasm_invoke_jsexport_async_post(targetTID: PThreadPtr, method: MonoMethod, args: VoidPtr): void;
     mono_wasm_invoke_jsexport_sync_send(targetTID: PThreadPtr, method: MonoMethod, args: VoidPtr): void;
     mono_wasm_invoke_jsexport_sync(method: MonoMethod, args: VoidPtr): void;
+    mono_wasm_invoke_jsexport_by_handle_async_post(targetTID: PThreadPtr, handle: CSFnHandle, args: VoidPtr): void;
+    mono_wasm_invoke_jsexport_by_handle_sync_send(targetTID: PThreadPtr, handle: CSFnHandle, args: VoidPtr): void;
+    mono_wasm_invoke_jsexport_by_handle_sync(handle: CSFnHandle, args: VoidPtr): void;
     mono_wasm_create_deputy_thread(): PThreadPtr;
     mono_wasm_create_io_thread(): PThreadPtr;
     mono_wasm_register_ui_thread(): void;
@@ -189,6 +197,8 @@ export interface t_Cwraps {
     mono_wasm_set_main_args(argc: number, argv: VoidPtr): void;
     mono_wasm_exec_regression(verbose_level: number, image: string): number;
     mono_wasm_invoke_jsexport(method: MonoMethod, args: JSMarshalerArguments): void;
+    mono_wasm_set_jsexport_dispatcher(method: MonoMethod): void;
+    mono_wasm_invoke_jsexport_by_handle(handle: CSFnHandle, args: JSMarshalerArguments): void;
     mono_wasm_write_managed_pointer_unsafe(destination: VoidPtr | MonoObjectRef, pointer: ManagedPointer): void;
     mono_wasm_copy_managed_pointer(destination: VoidPtr | MonoObjectRef, source: VoidPtr | MonoObjectRef): void;
     mono_wasm_i52_to_f64(source: VoidPtr, error: Int32Ptr): number;