Async Tasks (JSPI)

.github/workflows/ci.yml

@@ -45,7 +45,7 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v3
         with:
-          dotnet-version: '6.0.x'
+          dotnet-version: '8.0.x'
 
       - name: Restore Dependencies
         run: dotnet restore

.run/Wacs.Core Publish Wacs.Core.dll.run.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Wacs.Core Publish Wacs.Core.dll" type="ShConfigurationType" folderName="Unity Publish">
-    <option name="SCRIPT_TEXT" value="dotnet publish -c Release -o ../unity/Runtime/Plugins/" />
+    <option name="SCRIPT_TEXT" value="dotnet publish -f netstandard2.1 -c Release -o ../unity/Runtime/Plugins/" />
     <option name="INDEPENDENT_SCRIPT_PATH" value="true" />
     <option name="SCRIPT_PATH" value="" />
     <option name="SCRIPT_OPTIONS" value="" />

.run/Wacs.Core Publish Wacs.WASIp1.dll.run.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Wacs.Core Publish Wacs.WASIp1.dll" type="ShConfigurationType" folderName="Unity Publish">
-    <option name="SCRIPT_TEXT" value="dotnet publish -c Release -o ../unity/Runtime/Plugins/" />
+    <option name="SCRIPT_TEXT" value="dotnet publish -f netstandard2.1 -c Release -o ../unity/Runtime/Plugins/" />
     <option name="INDEPENDENT_SCRIPT_PATH" value="true" />
     <option name="SCRIPT_PATH" value="" />
     <option name="SCRIPT_OPTIONS" value="" />

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## [0.3.0]
+- Implemented JSPI-like async binding and execution
+- Hooked up more super-instruction threading
+
 ## [0.2.0]
 - Implemented super-instruction threading
 - Precomputed (non-allocating) block labels

Feature.Detect/DetectFeatures.cs

@@ -1,11 +1,28 @@
-using System;
+// /*
+//  * Copyright 2024 Kelvin Nishikawa
+//  *
+//  * Licensed under the Apache License, Version 2.0 (the "License");
+//  * you may not use this file except in compliance with the License.
+//  * You may obtain a copy of the License at
+//  *
+//  *     http://www.apache.org/licenses/LICENSE-2.0
+//  *
+//  * Unless required by applicable law or agreed to in writing, software
+//  * distributed under the License is distributed on an "AS IS" BASIS,
+//  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  * See the License for the specific language governing permissions and
+//  * limitations under the License.
+//  */
+
+using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using Spec.Test;
 using Wacs.Core;
 using Wacs.Core.Runtime;
 using Wacs.Core.Types;
 using Xunit;
-using Xunit.Abstractions;
 
 namespace Feature.Detect
 {
@@ -40,7 +57,13 @@ public void Detect(FeatureJson.FeatureJson file)
             }
             else
             {
-                Assert.Fail($"{file.Name} not supported.");
+                var supportedJsParadigms = new List<string>
+                {
+                    "jspi"
+                };
+
+                var supported = file.Features?.All(feature => supportedJsParadigms.Contains(feature)) ?? false;
+                Assert.True(supported, $"{file.Name} not supported.");
             }
         }
     }

Feature.Detect/Feature.Detect.csproj

@@ -2,10 +2,10 @@
 
     <PropertyGroup>
         <OutputType>Library</OutputType>
-        <TargetFramework>net6.0</TargetFramework>
         <ImplicitUsings>disable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <LangVersion>9</LangVersion>
+        <TargetFrameworks>net8.0;netstandard2.1</TargetFrameworks>
     </PropertyGroup>
 
     <ItemGroup>

Feature.Detect/FeatureJson/FeatureJson.cs

@@ -52,7 +52,6 @@ public override string ToString()
                 .Append("}");
             return sb.ToString();
         }
-
     }
 
     public class Options

Feature.Detect/trx-to-markdown.js

@@ -60,11 +60,11 @@ class TrxToMarkdown {
                 testDef['Phase'] = 0;
             }
 
+            testDef['outcome'] = test.outcome;
             if (testDef['Source'].includes('in WebAssembly'))
-                testDef['outcome'] = 'Javascript';
-            else
-                testDef['outcome'] = test.outcome;
-
+                testDef['outcome'] = 'JS.' + testDef['outcome'];
+            else if (testDef.Id == 'big-int')
+                testDef['outcome'] = 'JS.' + testDef['outcome'];
 
             tests.push(testDef);
         });
@@ -96,9 +96,10 @@ class TrxToMarkdown {
 
             let status = '❔';
             switch (testDef['outcome']) {
-                case 'Passed': status = '✅'; break;
-                case 'Javascript': status = '<span title="Browser idioms, not directly supported">🌐</span>'; break;
                 case 'Failed': status = '❌'; break;
+                case 'Passed': status = '✅'; break;
+                case 'JS.Failed': status = '<span title="Browser idioms, not directly supported">🌐</span>'; break;
+                case 'JS.Passed': status = '<span title="Browser idiom, but conceptually supported">✳️</span>'; break;
             }
             markdown.push(`|[${testDef['Name']}](${testDef['Proposal']})|${testDef['Features']}|${status}|`);
         });

README.md

@@ -34,6 +34,7 @@ The chapters and sections from the spec are commented throughout the source code
 - **Unity Compatibility**: Compatible with **Unity 2021.3+** including AOT/IL2CPP modes for iOS.
 - **Full WebAssembly MVP Compliance**: Passes the  [WebAssembly spec test suite](https://github.com/WebAssembly/spec/tree/main/test/core).
 - **Magical Interop**: Host bindings are validated with reflection, no boilerplate code required.
+- **Async Tasks**: [JSPI](https://github.com/WebAssembly/js-promise-integration)-like non-blocking calls for async functions.
 - **WASI:** Wacs.WASIp1 provides a [wasi\_snapshot\_preview1](https://github.com/WebAssembly/WASI/blob/main/legacy/preview1/docs.md) implementation.
 
 ## Getting Started
@@ -228,27 +229,33 @@ How does this differ from executing the wasm instructions linearly with the WACS
 - The CLR's implementation can use hardware more effectively (use registers instead of heap memory)
 - Avoids instruction fetching and dispatch
 
-In my testing, this leads to roughly 60% higher instruction processing throughput (10Mips -> 16Mips). These gains are situational however.
+In my testing, this leads to roughly 60% higher instruction processing throughput (128Mips -> 210Mips). These gains are situational however.
 Linking of the instructions into a tree cannot 100% be determined across block boundaries. So in these cases, the transpiler just passes
 the sequence through unaltered. So WASM code with lots of function calls or branches will see less benefit.
 
-There's still some headroom for optimization. Optimization is an ongoing process and I have a few other strategies yet to implement.
+### Prebaked Block Labels
+The design of the WASM VM includes block labelling for branch instructions and a heterogeneous operand/control stack.
+WACS uses a split stack that separates operands and control. This enables us to make some key optimizations:
+- Non-flushing branch jumps. We can leave operands on the stack if intermediate states don't interfere.
+- Precomputed block labels. We can ditch the control frame's label stack entirely!
+- Modern C# ObjectPools and ArrayPools minimize unavoidable allocation
+
+Optimization is an ongoing process and I have a few other strategies yet to implement.
 
 My plan for 1.0 includes:
 - Prebaked super-instructions for memory operations
-- Replace some object pools with pre-computed statics
 - Implement the above transpiling for SIMD instructions (currently only i32/i64/f32/f64 instructions are optimized)
 - Provide an API for 3rd party super-instruction optimization
 
 ## Roadmap
 
 The current TODO list includes:
 
-- **ExecAsync**: Thread scheduling and advanced gas metering (basically JSPI, but C# Tasks)
+- **Source Generated Bindings**: Use Roslyn source generator for generating bindings.
 - **Wasm Garbage Collection**: Support  wasm-gc and heaptypes.
-- **Text Format Parsing**: Add support for WebAssembly text format.
 - **WASI p1 Test Suite**: Validate WASIp1 with the test suite for improved standard compliance.
 - **WASI p2 and Component Model**: Implement the component model proposal.
+- **Text Format Parsing**: Add support for WebAssembly text format.
 - **SIMD Intrinsics**: Add hardware-accelerated SIMD (software implementation included in Wacs.Core).
 - **Unity Bindings for SDL**: Implement SDL2 with Unity bindings.
 - **JavaScript Proxy Bindings**: Maybe support common JS env functions.
@@ -263,7 +270,7 @@ Harnessed results from [wasm-feature-detect](https://github.com/GoogleChromeLabs
 |Proposal |Features|    |
 |------|-------|----|
 |Phase 5|
-|[JavaScript BigInt to WebAssembly i64 integration](https://github.com/WebAssembly/JS-BigInt-integration)||✅|
+|[JavaScript BigInt to WebAssembly i64 integration](https://github.com/WebAssembly/JS-BigInt-integration)||<span title="Browser idiom, but conceptually supported">✳️</span>|
 |[Bulk memory operations](https://github.com/webassembly/bulk-memory-operations)||✅|
 |[Extended Constant Expressions](https://github.com/WebAssembly/extended-const)|extended_const|✅|
 |[Garbage collection](https://github.com/WebAssembly/gc)|gc|❌|
@@ -283,7 +290,7 @@ Harnessed results from [wasm-feature-detect](https://github.com/GoogleChromeLabs
 |[Memory64](https://github.com/WebAssembly/memory64)|memory64|❌|
 |[Threads](https://github.com/webassembly/threads)|threads|❌|
 |Phase 3|
-|[JS Promise Integration](https://github.com/WebAssembly/js-promise-integration)|jspi|<span title="Browser idioms, not directly supported">🌐</span>|
+|[JS Promise Integration](https://github.com/WebAssembly/js-promise-integration)|jspi|<span title="Browser idiom, but conceptually supported">✳️</span>|
 |[Type Reflection for WebAssembly JavaScript API](https://github.com/WebAssembly/js-types)|type-reflection|<span title="Browser idioms, not directly supported">🌐</span>|
 ||
 |[Legacy Exception Handling]( https://github.com/WebAssembly/exception-handling)|exceptions|❌|

Spec.Test/BindingTests.cs

@@ -15,7 +15,9 @@
 //  */
 
 using System;
+using System.Diagnostics;
 using System.IO;
+using System.Threading.Tasks;
 using Wacs.Core;
 using Wacs.Core.Runtime;
 using Xunit;
@@ -24,11 +26,26 @@ namespace Spec.Test
 {
     public class BindingTests
     {
+        static int BoundHost(int a, out int b)
+        {
+            b = a;
+            int c = a * 2;
+            return c;
+        }
+
+        static async Task<int> BoundAsyncHost(int a)
+        {
+            await Task.Delay(1000); // Simulate work
+            return a*2;
+        }
+
+
         [Fact]
         public void BindStackBinder()
         {
             var runtime = new WasmRuntime();
-            runtime.BindHostFunction<hostInOut>(("env","bound_host"), BoundHost);
+            runtime.BindHostFunction<HostInOut>(("env","bound_host"), BoundHost);
+            runtime.BindHostFunction<HostAsyncInRet>(("env","bound_async_host"), BoundAsyncHost);
             using var fileStream = new FileStream("../../../engine/binding.wasm", FileMode.Open);
             var module = BinaryModuleParser.ParseWasm(fileStream);
             var moduleInst = runtime.InstantiateModule(module);
@@ -49,7 +66,8 @@ public void BindStackBinder()
         public void BindParamAndResultI32()
         {
             var runtime = new WasmRuntime();
-            runtime.BindHostFunction<hostInOut>(("env","bound_host"), BoundHost);
+            runtime.BindHostFunction<HostInOut>(("env","bound_host"), BoundHost);
+            runtime.BindHostFunction<HostAsyncInRet>(("env","bound_async_host"), BoundAsyncHost);
             using var fileStream = new FileStream("../../../engine/binding.wasm", FileMode.Open);
             var module = BinaryModuleParser.ParseWasm(fileStream);
             var moduleInst = runtime.InstantiateModule(module);
@@ -67,7 +85,8 @@ public void BindParamAndResultI32()
         public void BindParamAndResultF32()
         {
             var runtime = new WasmRuntime();
-            runtime.BindHostFunction<hostInOut>(("env","bound_host"), BoundHost);
+            runtime.BindHostFunction<HostInOut>(("env","bound_host"), BoundHost);
+            runtime.BindHostFunction<HostAsyncInRet>(("env","bound_async_host"), BoundAsyncHost);
             using var fileStream = new FileStream("../../../engine/binding.wasm", FileMode.Open);
             var module = BinaryModuleParser.ParseWasm(fileStream);
             var moduleInst = runtime.InstantiateModule(module);
@@ -81,18 +100,12 @@ public void BindParamAndResultF32()
             Assert.Equal(3f * 2f, invoker(3f));
         }
 
-        static int BoundHost(int a, out int b)
-        {
-            b = a;
-            int c = a * 2;
-            return c;
-        }
-
         [Fact]
         public void BindHostFunction()
         {
             var runtime = new WasmRuntime();
-            runtime.BindHostFunction<hostInOut>(("env","bound_host"), BoundHost);
+            runtime.BindHostFunction<HostInOut>(("env","bound_host"), BoundHost);
+            runtime.BindHostFunction<HostAsyncInRet>(("env","bound_async_host"), BoundAsyncHost);
 
             using var fileStream = new FileStream("../../../engine/binding.wasm", FileMode.Open);
             var module = BinaryModuleParser.ParseWasm(fileStream);
@@ -105,6 +118,61 @@ public void BindHostFunction()
             Assert.Equal(10 + 20, invoker(10));
         }
 
-        delegate int hostInOut(int a, out int b);
+
+        [Fact]
+        public void BindAsyncHostFunction()
+        {
+            var runtime = new WasmRuntime();
+            runtime.BindHostFunction<HostInOut>(("env","bound_host"), BoundHost);
+            runtime.BindHostFunction<HostAsyncInRet>(("env","bound_async_host"), BoundAsyncHost);
+
+            using var fileStream = new FileStream("../../../engine/binding.wasm", FileMode.Open);
+            var module = BinaryModuleParser.ParseWasm(fileStream);
+            var moduleInst = runtime.InstantiateModule(module);
+            runtime.RegisterModule("binding", moduleInst);
+
+            var fa = runtime.GetExportedFunction(("binding", "call_async_host"));
+
+            //Host function is async, Wasm function is called synchronously
+            var invoker = runtime.CreateInvoker<Func<int, int>>(fa);
+
+            Assert.Equal(10*2, invoker(10));
+        }
+
+        [Fact]
+        public async Task BindAsyncWasmFunction()
+        {
+            var runtime = new WasmRuntime();
+            runtime.BindHostFunction<HostInOut>(("env","bound_host"), BoundHost);
+
+            runtime.BindHostFunction<HostAsyncInRet>(("env","bound_async_host"), static async a =>
+            {
+                await Task.Delay(3_000); // Simulate work
+                return a*2;
+            });
+
+            using var fileStream = new FileStream("../../../engine/binding.wasm", FileMode.Open);
+            var module = BinaryModuleParser.ParseWasm(fileStream);
+            var moduleInst = runtime.InstantiateModule(module);
+            runtime.RegisterModule("binding", moduleInst);
+
+            var fa = runtime.GetExportedFunction(("binding", "call_async_host"));
+
+            //Host function is async, Wasm function is called asynchronously
+            var invoker = runtime.CreateStackInvokerAsync(fa);
+
+            var stopwatch = new Stopwatch();
+
+            stopwatch.Start();
+            var results = await invoker(10);
+            stopwatch.Stop();
+
+            Assert.InRange(stopwatch.ElapsedMilliseconds, 3000, 3500);
+            Assert.Equal(10*2, results[0].Int32);
+        }
+
+        delegate int HostInOut(int a, out int b);
+
+        delegate Task<int> HostAsyncInRet(int a);
     }
 }

Spec.Test/Spec.Test.csproj

@@ -1,15 +1,15 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <OutputType>Exe</OutputType>
-        <TargetFramework>net6.0</TargetFramework>
+        <OutputType>Library</OutputType>
         <LangVersion>9</LangVersion>
         <Nullable>enable</Nullable>
         <Title>WebAssembly Spec Wast Test suite harness</Title>
         <Authors>Kelvin Nishikawa</Authors>
         <Company>Kelvin Nishikawa</Company>
         <Product>Spec.Test</Product>
         <AssemblyVersion>1.0.1</AssemblyVersion>
+        <TargetFramework>net8.0</TargetFramework>
     </PropertyGroup>
 
     <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">

Spec.Test/WastJson/Argument.cs

@@ -18,6 +18,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Runtime.InteropServices;
 using System.Text.Json;
 using System.Text.Json.Serialization;
 using Wacs.Core.Runtime;
@@ -137,7 +138,7 @@ private static float BitBashFloat(string intval)
             if (value > int.MaxValue && value <= uint.MaxValue)
             {
                 uint v = (uint)value;
-                return BitConverter.UInt32BitsToSingle(v);
+                return MemoryMarshal.Cast<uint, float>(MemoryMarshal.CreateSpan(ref v, 1))[0];
             }
 
             return BitConverter.Int32BitsToSingle((int)value);
@@ -156,7 +157,7 @@ private static double BitBashDouble(string longval)
             if (value > long.MaxValue && value <= ulong.MaxValue)
             {
                 ulong v = (ulong)value;
-                return BitConverter.UInt64BitsToDouble(v);
+                return MemoryMarshal.Cast<ulong, double>(MemoryMarshal.CreateSpan(ref v, 1))[0];
             }
 
             return BitConverter.Int64BitsToDouble((long)value);

Spec.Test/WastTests.cs

@@ -62,7 +62,7 @@ public void RunWast(WastJson.WastJson file)
                 }
             }
         }
-        
+
         [Theory]
         [ClassData(typeof(WastJsonTestData))]
         public void RunWastTranspiled(WastJson.WastJson file)