[WASI] timers based on wasi:clocks

eng/illink.targets

@@ -20,8 +20,6 @@
     <ILLinkTrimOutputPath>$(IntermediateOutputPath)</ILLinkTrimOutputPath>
 
     <ILLinkDescriptorsXml Condition="'$(ILLinkDescriptorsXml)' == '' and Exists('$(ILLinkDirectory)ILLink.Descriptors.xml')">$(ILLinkDirectory)ILLink.Descriptors.xml</ILLinkDescriptorsXml>
-    <!-- ILLink.Descriptors.LibraryBuild.xml files are only used during building the library, not an app. They shouldn't be embedded into the assembly. -->
-    <ILLinkDescriptorsLibraryBuildXml Condition="'$(ILLinkDescriptorsLibraryBuildXml)' == '' and Exists('$(ILLinkDirectory)ILLink.Descriptors.LibraryBuild.xml')">$(ILLinkDirectory)ILLink.Descriptors.LibraryBuild.xml</ILLinkDescriptorsLibraryBuildXml>
     <ILLinkDescriptorsXmlIntermediatePath>$(IntermediateOutputPath)ILLink.Descriptors.xml</ILLinkDescriptorsXmlIntermediatePath>
 
     <ILLinkSubstitutionsXmlIntermediatePath>$(IntermediateOutputPath)ILLink.Substitutions.xml</ILLinkSubstitutionsXmlIntermediatePath>
@@ -41,6 +39,9 @@
   </PropertyGroup>
 
    <ItemGroup>
+    <!-- ILLink.Descriptors.LibraryBuild.xml files are only used during building the library, not an app. They shouldn't be embedded into the assembly. -->
+    <ILLinkDescriptorsLibraryBuildXml Include="$(ILLinkDirectory)ILLink.Descriptors.LibraryBuild.xml"
+                                      Condition="Exists('$(ILLinkDirectory)ILLink.Descriptors.LibraryBuild.xml')" />
     <ILLinkSuppressionsLibraryBuildXml Include="$(ILLinkSuppressionsXmlPrefix).LibraryBuild.xml"
                                        Condition="Exists('$(ILLinkSuppressionsXmlPrefix).LibraryBuild.xml')" />
 
@@ -210,7 +211,7 @@
       <ILLinkArgs Condition="'$(ILLinkRewritePDBs)' == 'true' and Exists('$(ILLinkTrimAssemblySymbols)')">$(ILLinkArgs) -b true</ILLinkArgs>
       <ILLinkArgs Condition="'$(ILLinkRewritePDBs)' == 'true' and Exists('$(ILLinkTrimAssemblySymbols)') and '$(DeterministicSourcePaths)' == 'true'">$(ILLinkArgs) --preserve-symbol-paths</ILLinkArgs>
       <!-- pass the non-embedded descriptors xml file on the command line -->
-      <ILLinkArgs Condition="'$(ILLinkDescriptorsLibraryBuildXml)' != ''">$(ILLinkArgs) -x "$(ILLinkDescriptorsLibraryBuildXml)"</ILLinkArgs>
+      <ILLinkArgs Condition="'@(ILLinkDescriptorsLibraryBuildXml)' != ''">$(ILLinkArgs) -x "@(ILLinkDescriptorsLibraryBuildXml->'%(FullPath)', '" -x "')"</ILLinkArgs>
       <ILLinkArgs Condition="'$(ILLinkSubstitutionsLibraryBuildXml)' != ''">$(ILLinkArgs) --substitutions "$(ILLinkSubstitutionsLibraryBuildXml)"</ILLinkArgs>
       <ILLinkArgs Condition="'@(ILLinkSuppressionsLibraryBuildXml)' != ''">$(ILLinkArgs) --link-attributes "@(ILLinkSuppressionsLibraryBuildXml->'%(FullPath)', '" --link-attributes "')"</ILLinkArgs>
       <!-- suppress warnings with the following codes:

src/libraries/Common/tests/WasmTestRunner/WasmTestRunner.cs

@@ -3,16 +3,35 @@
 
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.DotNet.XHarness.TestRunners.Common;
 using Microsoft.DotNet.XHarness.TestRunners.Xunit;
+using System.Runtime.CompilerServices;
 
 public class WasmTestRunner : WasmApplicationEntryPoint
 {
     protected int MaxParallelThreadsFromArg { get; set; }
     protected override int? MaxParallelThreads => RunInParallel ? MaxParallelThreadsFromArg : base.MaxParallelThreads;
 
-    public static async Task<int> Main(string[] args)
+#if TARGET_WASI
+    public static int Main(string[] args)
+    {
+        return PollWasiEventLoopUntilResolved((Thread)null!, MainAsync(args));
+
+        [UnsafeAccessor(UnsafeAccessorKind.StaticMethod, Name = "PollWasiEventLoopUntilResolved")]
+        static extern int PollWasiEventLoopUntilResolved(Thread t, Task<int> mainTask);
+    }
+
+
+#else
+    public static Task<int> Main(string[] args)
+    {
+        return MainAsync(args);
+    }
+#endif
+
+    public static async Task<int> MainAsync(string[] args)
     {
         if (args.Length == 0)
         {

src/libraries/Common/tests/WasmTestRunner/WasmTestRunner.csproj

@@ -2,7 +2,13 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <Nullable>enable</Nullable>
-    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
+    <TargetFrameworks>$(NetCoreAppCurrent)-browser;$(NetCoreAppCurrent)-wasi;$(NetCoreAppCurrent)</TargetFrameworks>
+  </PropertyGroup>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'browser'">$(DefineConstants);TARGET_BROWSER</DefineConstants>
+    <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'wasi'">$(DefineConstants);TARGET_WASI</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="WasmTestRunner.cs" />

src/libraries/System.Net.Http/src/System/Net/Http/WasiHttpHandler/WasiHttpHandler.cs

@@ -314,7 +314,7 @@ ITypes.OutgoingRequest request
                 }
                 else
                 {
-                    await WasiEventLoop.RegisterWasiPollable(future.Subscribe()).ConfigureAwait(false);
+                    await RegisterWasiPollable(future.Subscribe()).ConfigureAwait(false);
                 }
             }
         }
@@ -461,19 +461,22 @@ private static async Task SendContentAsync(HttpContent? content, Stream stream)
             }
         }
 
-        private static class WasiEventLoop
+        private static Task RegisterWasiPollable(IPoll.Pollable pollable)
         {
-            internal static Task RegisterWasiPollable(IPoll.Pollable pollable)
-            {
-                var handle = pollable.Handle;
-                pollable.Handle = 0;
-                return CallRegisterWasiPollable((Thread)null!, handle);
+            var handle = pollable.Handle;
+
+            // this will effectively neutralize Dispose() of the Pollable()
+            // because in the CoreLib we create another instance, which will dispose it
+            pollable.Handle = 0;
+            GC.SuppressFinalize(pollable);
+
+            return CallRegisterWasiPollableHandle((Thread)null!, handle);
 
-                [UnsafeAccessor(UnsafeAccessorKind.StaticMethod, Name = "RegisterWasiPollable")]
-                static extern Task CallRegisterWasiPollable(Thread t, int handle);
-            }
         }
 
+        [UnsafeAccessor(UnsafeAccessorKind.StaticMethod, Name = "RegisterWasiPollableHandle")]
+        private static extern Task CallRegisterWasiPollableHandle(Thread t, int handle);
+
         private sealed class InputStream : Stream
         {
             private ITypes.IncomingBody body;
@@ -559,8 +562,7 @@ CancellationToken cancellationToken
                             var buffer = result;
                             if (buffer.Length == 0)
                             {
-                                await WasiEventLoop
-                                    .RegisterWasiPollable(stream.Subscribe())
+                                await RegisterWasiPollable(stream.Subscribe())
                                     .ConfigureAwait(false);
                             }
                             else
@@ -697,7 +699,7 @@ CancellationToken cancellationToken
                     var count = (int)stream.CheckWrite();
                     if (count == 0)
                     {
-                        await WasiEventLoop.RegisterWasiPollable(stream.Subscribe()).ConfigureAwait(false);
+                        await RegisterWasiPollable(stream.Subscribe()).ConfigureAwait(false);
                     }
                     else if (offset == limit)
                     {

src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Descriptors.LibraryBuild.WASI.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<linker>
+	<assembly fullname="System.Private.CoreLib">
+		<!-- these methods are temporarily accessed via UnsafeAccessor from generated code until we have it in public API, probably in WASI preview3 and promises -->
+		<type fullname="System.Threading.Thread">
+			<method name="RegisterWasiPollableHandle" />
+			<method name="PollWasiEventLoopUntilResolved" />
+		</type>
+	</assembly>
+</linker>

src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems

@@ -64,10 +64,9 @@
     <ILLinkSubstitutionsXmls Include="$(ILLinkSharedDirectory)ILLink.Substitutions.Browser.xml" Condition="'$(TargetsBrowser)' == 'true'" />
     <ILLinkLinkAttributesXmls Include="$(ILLinkSharedDirectory)ILLink.LinkAttributes.Shared.xml" />
     <ILLinkSuppressionsLibraryBuildXml Include="$(ILLinkSharedDirectory)ILLink.Suppressions.LibraryBuild.xml" />
+    <ILLinkDescriptorsLibraryBuildXml Include="$(ILLinkSharedDirectory)ILLink.Descriptors.LibraryBuild.xml" />
+    <ILLinkDescriptorsLibraryBuildXml Include="$(ILLinkSharedDirectory)ILLink.Descriptors.LibraryBuild.WASI.xml" Condition="'$(TargetsWasi)' == 'true'" />
   </ItemGroup>
-  <PropertyGroup>
-    <ILLinkDescriptorsLibraryBuildXml>$(ILLinkSharedDirectory)ILLink.Descriptors.LibraryBuild.xml</ILLinkDescriptorsLibraryBuildXml>
-  </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(MSBuildThisFileDirectory)Internal\AssemblyAttributes.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Internal\Console.cs" />
@@ -2804,6 +2803,7 @@
   <ItemGroup Condition="'$(TargetsWasi)' == 'true'">
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\Wasi\WasiEventLoop.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\Wasi\WasiPoll.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\Threading\Wasi\WasiPollWorld.wit.imports.wasi.clocks.v0_2_1.MonotonicClockInterop.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\Wasi\WasiPollWorld.wit.imports.wasi.io.v0_2_1.IPoll.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\Wasi\WasiPollWorld.wit.imports.wasi.io.v0_2_1.PollInterop.cs" />
   </ItemGroup>

src/libraries/System.Private.CoreLib/src/System/Threading/Thread.Unix.cs

@@ -5,22 +5,34 @@
 using System.Runtime;
 using System.Runtime.InteropServices;
 using Microsoft.Win32.SafeHandles;
+using System.Threading.Tasks;
 
 namespace System.Threading
 {
     public sealed partial class Thread
     {
         // these methods are temporarily accessed via UnsafeAccessor from generated code until we have it in public API, probably in WASI preview3 and promises
 #if TARGET_WASI
-        internal static System.Threading.Tasks.Task RegisterWasiPollable(int handle)
+        internal static System.Threading.Tasks.Task RegisterWasiPollableHandle(int handle)
         {
-            return WasiEventLoop.RegisterWasiPollable(handle);
+            return WasiEventLoop.RegisterWasiPollableHandle(handle);
         }
 
-        internal static void DispatchWasiEventLoop()
+        internal static int PollWasiEventLoopUntilResolved(Task<int> mainTask)
         {
-            WasiEventLoop.DispatchWasiEventLoop();
+            while (!mainTask.IsCompleted)
+            {
+                WasiEventLoop.DispatchWasiEventLoop();
+            }
+            var exception = mainTask.Exception;
+            if (exception is not null)
+            {
+                throw exception;
+            }
+
+            return mainTask.Result;
         }
+
 #endif
 
         // the closest analog to Sleep(0) on Unix is sched_yield

src/libraries/System.Private.CoreLib/src/System/Threading/Wasi/WasiEventLoop.cs

@@ -9,43 +9,64 @@ namespace System.Threading
 {
     internal static class WasiEventLoop
     {
-        private static List<(IPoll.Pollable, TaskCompletionSource)> pollables = new();
+        private static List<WeakReference<TaskCompletionSource>> s_pollables = new();
 
-        internal static Task RegisterWasiPollable(int handle)
+        internal static Task RegisterWasiPollableHandle(int handle)
         {
-            var source = new TaskCompletionSource(TaskCreationOptions.AttachedToParent);
-            pollables.Add((new IPoll.Pollable(new IPoll.Pollable.THandle(handle)), source));
-            return source.Task;
+            // note that this is duplicate of the original Pollable
+            // the original should be neutralized without disposing the handle
+            var pollableCpy = new IPoll.Pollable(new IPoll.Pollable.THandle(handle));
+            return RegisterWasiPollable(pollableCpy);
+        }
+
+        internal static Task RegisterWasiPollable(IPoll.Pollable pollable)
+        {
+            var tcs = new TaskCompletionSource(pollable);
+            var weakRef = new WeakReference<TaskCompletionSource>(tcs);
+            s_pollables.Add(weakRef);
+            return tcs.Task;
         }
 
         internal static void DispatchWasiEventLoop()
         {
             ThreadPoolWorkQueue.Dispatch();
 
-            if (WasiEventLoop.pollables.Count > 0)
+            if (s_pollables.Count > 0)
             {
-                var pollables = WasiEventLoop.pollables;
-                WasiEventLoop.pollables = new();
-                var arguments = new List<IPoll.Pollable>();
-                var sources = new List<TaskCompletionSource>();
-                foreach ((var pollable, var source) in pollables)
+                var pollables = s_pollables;
+                s_pollables = new List<WeakReference<TaskCompletionSource>>(pollables.Count);
+                var arguments = new List<IPoll.Pollable>(pollables.Count);
+                var indexes = new List<int>(pollables.Count);
+                for (var i = 0; i < pollables.Count; i++)
                 {
-                    arguments.Add(pollable);
-                    sources.Add(source);
+                    var weakRef = pollables[i];
+                    if (weakRef.TryGetTarget(out TaskCompletionSource? tcs))
+                    {
+                        var pollable = (IPoll.Pollable)tcs!.Task.AsyncState!;
+                        arguments.Add(pollable);
+                        indexes.Add(i);
+                    }
                 }
-                var results = PollInterop.Poll(arguments);
+
+                // this is blocking until at least one pollable resolves
+                var readyIndexes = PollInterop.Poll(arguments);
+
                 var ready = new bool[arguments.Count];
-                foreach (var result in results)
+                foreach (int readyIndex in readyIndexes)
                 {
-                    ready[result] = true;
-                    arguments[(int)result].Dispose();
-                    sources[(int)result].SetResult();
+                    ready[readyIndex] = true;
+                    arguments[readyIndex].Dispose();
+                    var weakRef = pollables[indexes[readyIndex]];
+                    if (weakRef.TryGetTarget(out TaskCompletionSource? tcs))
+                    {
+                        tcs!.SetResult();
+                    }
                 }
                 for (var i = 0; i < arguments.Count; ++i)
                 {
                     if (!ready[i])
                     {
-                        WasiEventLoop.pollables.Add((arguments[i], sources[i]));
+                        s_pollables.Add(pollables[indexes[i]]);
                     }
                 }
             }

src/libraries/System.Private.CoreLib/src/System/Threading/Wasi/WasiPollWorld.wit.imports.wasi.clocks.v0_2_1.MonotonicClockInterop.cs

@@ -0,0 +1,81 @@
+// Generated by `wit-bindgen` 0.29.0. DO NOT EDIT!
+// <auto-generated />
+#nullable enable
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Collections;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+
+namespace WasiPollWorld.wit.imports.wasi.clocks.v0_2_1
+{
+    internal static class MonotonicClockInterop {
+
+        internal static class NowWasmInterop
+        {
+            [DllImport("wasi:clocks/monotonic-clock@0.2.1", EntryPoint = "now"), WasmImportLinkage]
+            internal static extern long wasmImportNow();
+
+        }
+
+        internal  static unsafe ulong Now()
+        {
+            var result =  NowWasmInterop.wasmImportNow();
+            return unchecked((ulong)(result));
+
+            //TODO: free alloc handle (interopString) if exists
+        }
+
+        internal static class ResolutionWasmInterop
+        {
+            [DllImport("wasi:clocks/monotonic-clock@0.2.1", EntryPoint = "resolution"), WasmImportLinkage]
+            internal static extern long wasmImportResolution();
+
+        }
+
+        internal  static unsafe ulong Resolution()
+        {
+            var result =  ResolutionWasmInterop.wasmImportResolution();
+            return unchecked((ulong)(result));
+
+            //TODO: free alloc handle (interopString) if exists
+        }
+
+        internal static class SubscribeInstantWasmInterop
+        {
+            [DllImport("wasi:clocks/monotonic-clock@0.2.1", EntryPoint = "subscribe-instant"), WasmImportLinkage]
+            internal static extern int wasmImportSubscribeInstant(long p0);
+
+        }
+
+        internal  static unsafe global::WasiPollWorld.wit.imports.wasi.io.v0_2_1.IPoll.Pollable SubscribeInstant(ulong when)
+        {
+            var result =  SubscribeInstantWasmInterop.wasmImportSubscribeInstant(unchecked((long)(when)));
+            var resource = new global::WasiPollWorld.wit.imports.wasi.io.v0_2_1.IPoll.Pollable(new global::WasiPollWorld.wit.imports.wasi.io.v0_2_1.IPoll.Pollable.THandle(result));
+            return resource;
+
+            //TODO: free alloc handle (interopString) if exists
+        }
+
+        internal static class SubscribeDurationWasmInterop
+        {
+            [DllImport("wasi:clocks/monotonic-clock@0.2.1", EntryPoint = "subscribe-duration"), WasmImportLinkage]
+            internal static extern int wasmImportSubscribeDuration(long p0);
+
+        }
+
+        internal  static unsafe global::WasiPollWorld.wit.imports.wasi.io.v0_2_1.IPoll.Pollable SubscribeDuration(ulong when)
+        {
+            var result =  SubscribeDurationWasmInterop.wasmImportSubscribeDuration(unchecked((long)(when)));
+            var resource = new global::WasiPollWorld.wit.imports.wasi.io.v0_2_1.IPoll.Pollable(new global::WasiPollWorld.wit.imports.wasi.io.v0_2_1.IPoll.Pollable.THandle(result));
+            return resource;
+
+            //TODO: free alloc handle (interopString) if exists
+        }
+
+    }
+}

src/libraries/System.Private.CoreLib/src/System/Threading/Wasi/generate-wasi-poll-bindings.sh

@@ -17,6 +17,7 @@ tar xzf v0.2.1.tar.gz
 cat >wasi-http-0.2.1/wit/world.wit <<EOF
 world wasi-poll {
   import wasi:io/poll@0.2.1;
+  import wasi:clocks/monotonic-clock@0.2.1;
 }
 EOF
 wit-bindgen c-sharp -w wasi-poll -r native-aot --internal --skip-support-files wasi-http-0.2.1/wit

src/libraries/tests.proj

@@ -581,6 +581,7 @@
     <SmokeTestProject Include="$(MSBuildThisFileDirectory)System.Runtime\tests\System.Buffers.Tests\System.Buffers.Tests.csproj" />
     <SmokeTestProject Include="$(MSBuildThisFileDirectory)System.Runtime\tests\System.Globalization.Tests\Invariant\Invariant.Tests.csproj" />
     <SmokeTestProject Include="$(MSBuildThisFileDirectory)System.Runtime\tests\System.Globalization.Tests\System.Globalization.Tests.csproj" />
+    <SmokeTestProject Include="$(MSBuildThisFileDirectory)System.Runtime\tests\System.Threading.Timer.Tests\System.Threading.Timer.Tests.csproj" />
   </ItemGroup>
 
   <!-- wasi/aot smoke tests -->