[browser][mt] Unify multithreading switches

eng/pipelines/extra-platforms/runtime-extra-platforms-wasm.yml

@@ -124,7 +124,7 @@ jobs:
         - browser_wasm
         #- browser_wasm_win
       nameSuffix: _Threading
-      extraBuildArgs: /p:MonoWasmBuildVariant=multithread /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
+      extraBuildArgs: /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
       isExtraPlatformsBuild: ${{ parameters.isExtraPlatformsBuild }}
       isWasmOnlyBuild: ${{ parameters.isWasmOnlyBuild }}
       # Always run for runtime-wasm because tests are not run in runtime
@@ -255,7 +255,7 @@ jobs:
         - browser_wasm
         - browser_wasm_win
       nameSuffix: MultiThreaded
-      extraBuildArgs: /p:MonoWasmBuildVariant=multithread /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
+      extraBuildArgs: /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
       condition: ne(variables['wasmMultiThreadedBuildOnlyNeededOnDefaultPipeline'], true)
       publishArtifactsForWorkload: true
       publishWBT: false
@@ -313,7 +313,7 @@ jobs:
       platforms:
         - Browser_wasm
         - Browser_wasm_win
-      extraBuildArgs: /p:MonoWasmBuildVariant=multithread /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
+      extraBuildArgs: /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
       nameSuffix: DebuggerTests_MultiThreaded
       alwaysRun: ${{ parameters.isWasmOnlyBuild }}
       isExtraPlatformsBuild: ${{ parameters.isExtraPlatformsBuild }}

eng/pipelines/runtime-official.yml

@@ -394,7 +394,7 @@ extends:
           platforms:
           - browser_wasm
           jobParameters:
-            buildArgs: -s mono+libs+host+packs -c $(_BuildConfig) /p:MonoWasmBuildVariant=multithread /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
+            buildArgs: -s mono+libs+host+packs -c $(_BuildConfig) /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
             nameSuffix: Mono_multithread
             isOfficialBuild: ${{ variables.isOfficialBuild }}
             runtimeVariant: multithread

eng/pipelines/runtime.yml

@@ -565,7 +565,7 @@ extends:
             - browser_wasm_win
           condition: or(eq(variables.isRollingBuild, true), eq(variables.wasmSingleThreadedBuildOnlyNeededOnDefaultPipeline, true))
           nameSuffix: MultiThreaded
-          extraBuildArgs: /p:MonoWasmBuildVariant=multithread /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
+          extraBuildArgs: /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
           publishArtifactsForWorkload: true
           publishWBT: false
 
@@ -601,7 +601,7 @@ extends:
           platforms:
             - browser_wasm
           nameSuffix: _Threading_Smoke
-          extraBuildArgs: /p:MonoWasmBuildVariant=multithread /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
+          extraBuildArgs: /p:WasmEnableThreads=true /p:AotHostArchitecture=x64 /p:AotHostOS=$(_hostedOS)
           shouldRunSmokeOnly: true
           alwaysRun: ${{ variables.isRollingBuild }}
           scenarios:

eng/testing/tests.browser.targets

@@ -87,15 +87,15 @@
     <_AppArgs Condition="'$(IsFunctionalTest)' != 'true' and '$(WasmMainAssemblyFileName)' != ''">--run $(WasmMainAssemblyFileName)</_AppArgs>
     <_AppArgs Condition="'$(IsFunctionalTest)' == 'true'">--run $(AssemblyName).dll</_AppArgs>
 
-    <_XUnitBackgroundExec Condition="'$(_XUnitBackgroundExec)' == '' and '$(MonoWasmBuildVariant)' == 'multithread'">true</_XUnitBackgroundExec>
+    <_XUnitBackgroundExec Condition="'$(_XUnitBackgroundExec)' == '' and '$(WasmEnableThreads)' == 'true'">true</_XUnitBackgroundExec>
     <WasmTestAppArgs Condition="'$(_XUnitBackgroundExec)' == 'true'">$(WasmTestAppArgs) -backgroundExec</WasmTestAppArgs>
     <_AppArgs Condition="'$(WasmTestAppArgs)' != ''">$(_AppArgs) $(WasmTestAppArgs)</_AppArgs>
 
     <WasmXHarnessMonoArgs Condition="'$(XunitShowProgress)' == 'true'">$(WasmXHarnessMonoArgs) --setenv=XHARNESS_LOG_TEST_START=1</WasmXHarnessMonoArgs>
     <!-- snapshots are not yet supported with threads -->
-    <WasmXHarnessMonoArgs Condition="'$(MonoWasmBuildVariant)' == 'multithread'">$(WasmXHarnessMonoArgs) --no-memory-snapshot</WasmXHarnessMonoArgs>
+    <WasmXHarnessMonoArgs Condition="'$(WasmEnableThreads)' == 'true'">$(WasmXHarnessMonoArgs) --no-memory-snapshot</WasmXHarnessMonoArgs>
     <!-- help unit test with PlatformDetection.IsThreadingSupported via IsBrowserThreadingSupported env variable -->
-    <WasmXHarnessMonoArgs Condition="'$(MonoWasmBuildVariant)' == 'multithread'">$(WasmXHarnessMonoArgs) --setenv=IsBrowserThreadingSupported=true</WasmXHarnessMonoArgs>
+    <WasmXHarnessMonoArgs Condition="'$(WasmEnableThreads)' == 'true'">$(WasmXHarnessMonoArgs) --setenv=IsBrowserThreadingSupported=true</WasmXHarnessMonoArgs>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(RunScriptCommand)' == ''">
@@ -104,7 +104,7 @@
 
     <_XHarnessArgs Condition="'$(IsFunctionalTest)' == 'true'"     >$(_XHarnessArgs) --expected-exit-code=$(ExpectedExitCode)</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(WasmXHarnessArgs)' != ''"         >$(_XHarnessArgs) $(WasmXHarnessArgs)</_XHarnessArgs>
-    <_XHarnessArgs Condition="'$(MonoWasmBuildVariant)' == 'multithread' and '$(_XHarnessArs.Contains(&quot;--web-server-use-cop&quot;)' != 'true'">$(_XHarnessArgs) --web-server-use-cop</_XHarnessArgs>
+    <_XHarnessArgs Condition="'$(WasmEnableThreads)' == 'true' and '$(_XHarnessArs.Contains(&quot;--web-server-use-cop&quot;)' != 'true'">$(_XHarnessArgs) --web-server-use-cop</_XHarnessArgs>
     <_XHarnessArgs                                                 >$(_XHarnessArgs) -s dotnet.native.js.symbols</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(_UseWasmSymbolicator)' == 'true'" >$(_XHarnessArgs) --symbol-patterns wasm-symbol-patterns.txt</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(_UseWasmSymbolicator)' == 'true'" >$(_XHarnessArgs) --symbolicator WasmSymbolicator.dll,Microsoft.WebAssembly.Internal.SymbolicatorWrapperForXHarness</_XHarnessArgs>

eng/testing/workloads-browser.targets

@@ -47,10 +47,14 @@
   <Target Name="_GetRuntimePackNuGetsToBuild" Condition="'$(WasmSkipMissingRuntimePackBuild)' != 'true'" Returns="@(_NuGetsToBuild)">
     <Error Condition="'$(RIDForWorkload)' == ''" Text="$(RIDForWorkload) is unset" />
     <PropertyGroup>
-      <_DefaultBuildVariant Condition="'$(MonoWasmBuildVariant)' == 'multithread'">.multithread.</_DefaultBuildVariant>
-      <_DefaultBuildVariant Condition="'$(_DefaultBuildVariant)' == ''">.</_DefaultBuildVariant>
-
-      <_DefaultRuntimePackNuGetPath>$(LibrariesShippingPackagesDir)Microsoft.NETCore.App.Runtime.Mono$(_DefaultBuildVariant)$(RIDForWorkload).$(PackageVersionForWorkloadManifests).nupkg</_DefaultRuntimePackNuGetPath>
+      <_BuildVariant Condition="'$(WasmEnableThreads)' == 'true'">multithread</_BuildVariant>
+      <_Descriptor Condition="'$(WasmEnableThreads)' == 'true'">runtime pack for $(_BuildVariant)</_Descriptor>
+      <_Descriptor Condition="'$(WasmEnableThreads)' != 'true'">single threaded runtime pack</_Descriptor>
+      <_DefaultRuntimePackNuGetPath>$([System.String]::Join('.',
+        $(LibrariesShippingPackagesDir)Microsoft.NETCore.App.Runtime.Mono,
+        $(_BuildVariant),
+        $(RIDForWorkload).$(PackageVersionForWorkloadManifests).nupkg))
+      </_DefaultRuntimePackNuGetPath>
     </PropertyGroup>
 
     <ItemGroup>
@@ -63,22 +67,11 @@
            Text="Expected to find either one or two in $(LibrariesShippingPackagesDir): @(_RuntimePackNugetAvailable->'%(FileName)%(Extension)')" />
 
     <ItemGroup>
-      <_BuildVariants Include="multithread" Condition="'$(_DefaultBuildVariant)' != '.multithread.'" />
-
-      <_NuGetsToBuild Include="$(LibrariesShippingPackagesDir)Microsoft.NETCore.App.Runtime.Mono.%(_BuildVariants.Identity).$(RIDForWorkload).$(PackageVersionForWorkloadManifests).nupkg"
-                      Project="$(InstallerProjectRoot)pkg/sfx/Microsoft.NETCore.App/Microsoft.NETCore.App.Runtime.sfxproj"
-                      Dependencies="$(_DefaultRuntimePackNuGetPath)"
-                      Properties="@(_DefaultPropsForNuGetBuild, ';');MonoWasmBuildVariant=%(_BuildVariants.Identity)"
-                      Descriptor="runtime pack for %(_BuildVariants.Identity)"
-                      Condition="'%(_BuildVariants.Identity)' != ''"/>
-
-      <!-- add for non-threaded runtime also -->
-      <_NuGetsToBuild Include="$(LibrariesShippingPackagesDir)Microsoft.NETCore.App.Runtime.Mono.$(RIDForWorkload).$(PackageVersionForWorkloadManifests).nupkg"
+      <_NuGetsToBuild Include="$(_DefaultRuntimePackNuGetPath)"
                       Project="$(InstallerProjectRoot)pkg/sfx/Microsoft.NETCore.App/Microsoft.NETCore.App.Runtime.sfxproj"
-                      Properties="@(_DefaultPropsForNuGetBuild, ';');MonoWasmBuildVariant="
                       Dependencies="$(_DefaultRuntimePackNuGetPath)"
-                      Descriptor="single threaded runtime pack"
-                      Condition="'$(_DefaultBuildVariant)' != '.'" />
+                      Properties="@(_DefaultPropsForNuGetBuild, ';');WasmEnableThreads=$(WasmEnableThreads)"
+                      Descriptor="$(_Descriptor)"/>
     </ItemGroup>
 
     <Message

src/installer/pkg/sfx/Microsoft.NETCore.App/Microsoft.NETCore.App.Runtime.props

@@ -32,8 +32,8 @@
   <PropertyGroup Condition="'$(MonoAOTEnableLLVM)' == 'true' and '$(RuntimeFlavor)' == 'Mono' and '$(TargetsMobile)' != 'true'">
     <RuntimeSpecificFrameworkSuffix>Mono.LLVM.AOT</RuntimeSpecificFrameworkSuffix>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(MonoWasmBuildVariant)' != ''">
-    <RuntimeSpecificFrameworkSuffix>Mono.$(MonoWasmBuildVariant)</RuntimeSpecificFrameworkSuffix>
+  <PropertyGroup Condition="'$(WasmEnableThreads)' == 'true'">
+    <RuntimeSpecificFrameworkSuffix>Mono.multithread</RuntimeSpecificFrameworkSuffix>
   </PropertyGroup>
   <PropertyGroup Condition="'$(RuntimeSpecificFrameworkSuffix)' != ''">
     <OverridePackageId>$(SharedFrameworkName).Runtime.$(RuntimeSpecificFrameworkSuffix).$(RuntimeIdentifier)</OverridePackageId>

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

@@ -27,7 +27,7 @@ internal static unsafe partial class Runtime
         public static extern void DeregisterGCRoot(nint handle);
 #endif
 
-#if FEATURE_WASM_THREADS
+#if FEATURE_WASM_MANAGED_THREADS
         [MethodImpl(MethodImplOptions.InternalCall)]
         public static extern void InstallWebWorkerInterop(nint proxyContextGCHandle);
         [MethodImpl(MethodImplOptions.InternalCall)]

src/libraries/System.Diagnostics.Tracing/src/System.Diagnostics.Tracing.csproj

@@ -6,7 +6,7 @@
     <UseCompilerGeneratedDocXmlFile>false</UseCompilerGeneratedDocXmlFile>
   </PropertyGroup>
 
-  <PropertyGroup Condition="'$(MonoWasmBuildVariant)' == 'multithread'">
+  <PropertyGroup Condition="'$(WasmEnableThreads)' == 'true'">
     <!-- when wasm threading is enabled the implementation in CoreLib won't have the UnsupportedOSAttribute for browser,
          but this contract still does since we only expose the wasm threading through System.Diagnostics.Tracing.WebAssembly.PerfTracing
          so we need to baseline the ApiCompat errors related to that -->

src/libraries/System.Linq.Parallel/src/System.Linq.Parallel.csproj

@@ -1,15 +1,15 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework Condition="'$(MonoWasmBuildVariant)' != 'multithread'">$(NetCoreAppCurrent)</TargetFramework>
-    <TargetFrameworks Condition="'$(MonoWasmBuildVariant)' == 'multithread'">$(NetCoreAppCurrent);$(NetCoreAppCurrent)-browser</TargetFrameworks>
+    <TargetFramework Condition="'$(WasmEnableThreads)' != 'true'">$(NetCoreAppCurrent)</TargetFramework>
+    <TargetFrameworks Condition="'$(WasmEnableThreads)' == 'true'">$(NetCoreAppCurrent);$(NetCoreAppCurrent)-browser</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <UseCompilerGeneratedDocXmlFile>false</UseCompilerGeneratedDocXmlFile>
   </PropertyGroup>
   <PropertyGroup>
     <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
-    <FeatureWasmThreads Condition="'$(TargetPlatformIdentifier)' == 'browser' and '$(MonoWasmBuildVariant)' == 'multithread'">true</FeatureWasmThreads>
-    <DefineConstants Condition="'$(FeatureWasmThreads)' == 'true'" >$(DefineConstants);FEATURE_WASM_THREADS</DefineConstants>
+    <FeatureWasmManagedThreads Condition="'$(TargetPlatformIdentifier)' == 'browser' and '$(WasmEnableThreads)' == 'true'">true</FeatureWasmManagedThreads>
+    <DefineConstants Condition="'$(FeatureWasmManagedThreads)' == 'true'" >$(DefineConstants);FEATURE_WASM_MANAGED_THREADS</DefineConstants>
   </PropertyGroup>
   <!-- Compiled Source Files -->
   <ItemGroup>
@@ -158,8 +158,8 @@
     <Reference Include="System.Diagnostics.Tracing" />
     <Reference Include="System.Linq" />
     <Reference Include="System.Runtime" />
-    <Reference Include="System.Threading" Condition="'$(MonoWasmBuildVariant)' != 'multithread'" />
-    <ProjectReference Include="$(LibrariesProjectRoot)System.Threading.WebAssembly.Threading\ref\System.Threading.WebAssembly.Threading.csproj" Condition="'$(MonoWasmBuildVariant)' == 'multithread'" />
+    <Reference Include="System.Threading" Condition="'$(WasmEnableThreads)' != 'true'" />
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Threading.WebAssembly.Threading\ref\System.Threading.WebAssembly.Threading.csproj" Condition="'$(WasmEnableThreads)' == 'true'" />
   </ItemGroup>
 
 </Project>

src/libraries/System.Linq.Parallel/src/System/Linq/Parallel/Channels/AsynchronousChannel.cs

@@ -17,7 +17,7 @@ namespace System.Linq.Parallel
     /// This is a bounded channel meant for single-producer/single-consumer scenarios.
     /// </summary>
     /// <typeparam name="T">Specifies the type of data in the channel.</typeparam>
-#if !FEATURE_WASM_THREADS
+#if !FEATURE_WASM_MANAGED_THREADS
     [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
 #endif
     internal sealed class AsynchronousChannel<T> : IDisposable

src/libraries/System.Linq.Parallel/src/System/Linq/Parallel/Merging/AsynchronousChannelMergeEnumerator.cs

@@ -26,7 +26,7 @@ namespace System.Linq.Parallel
     ///
     /// </summary>
     /// <typeparam name="T"></typeparam>
-#if !FEATURE_WASM_THREADS
+#if !FEATURE_WASM_MANAGED_THREADS
     [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
 #endif
     internal sealed class AsynchronousChannelMergeEnumerator<T> : MergeEnumerator<T>

src/libraries/System.Linq.Parallel/src/System/Linq/Parallel/Merging/MergeExecutor.cs

@@ -141,7 +141,7 @@ public IEnumerator<TInputOutput> GetEnumerator()
         //     An array of asynchronous channels, one for each partition.
         //
 
-#if !FEATURE_WASM_THREADS
+#if !FEATURE_WASM_MANAGED_THREADS
         [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
 #endif
         internal static AsynchronousChannel<TInputOutput>[] MakeAsynchronousChannels(int partitionCount, ParallelMergeOptions options, IntValueEvent? consumerEvent, CancellationToken cancellationToken)

src/libraries/System.Linq.Parallel/src/System/Linq/Parallel/Merging/OrderPreservingPipeliningMergeHelper.cs

@@ -36,7 +36,7 @@ namespace System.Linq.Parallel
     /// Finally, if the producer notices that its buffer has exceeded an even greater threshold, it will
     /// go to sleep and wait until the consumer takes the entire buffer.
     /// </summary>
-#if !FEATURE_WASM_THREADS
+#if !FEATURE_WASM_MANAGED_THREADS
     [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
 #endif
     internal sealed class OrderPreservingPipeliningMergeHelper<TOutput, TKey> : IMergeHelper<TOutput>

src/libraries/System.Linq.Parallel/src/System/Linq/Parallel/Scheduling/OrderPreservingPipeliningSpoolingTask.cs

@@ -18,7 +18,7 @@
 
 namespace System.Linq.Parallel
 {
-#if !FEATURE_WASM_THREADS
+#if !FEATURE_WASM_MANAGED_THREADS
     [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
 #endif
     internal sealed class OrderPreservingPipeliningSpoolingTask<TOutput, TKey> : SpoolingTaskBase

src/libraries/System.Linq.Parallel/src/System/Linq/Parallel/Scheduling/SpoolingTask.cs

@@ -82,7 +82,7 @@ internal static void SpoolStopAndGo<TInputOutput, TIgnoreKey>(
         //     taskScheduler   - the task manager on which to execute
         //
 
-#if !FEATURE_WASM_THREADS
+#if !FEATURE_WASM_MANAGED_THREADS
         [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
 #endif
         internal static void SpoolPipeline<TInputOutput, TIgnoreKey>(
@@ -264,7 +264,7 @@ protected override void SpoolingFinally()
     /// </summary>
     /// <typeparam name="TInputOutput"></typeparam>
     /// <typeparam name="TIgnoreKey"></typeparam>
-#if !FEATURE_WASM_THREADS
+#if !FEATURE_WASM_MANAGED_THREADS
     [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
 #endif
     internal sealed class PipelineSpoolingTask<TInputOutput, TIgnoreKey> : SpoolingTaskBase

src/libraries/System.Linq.Parallel/src/System/Linq/Parallel/Utils/Sorting.cs

@@ -351,7 +351,7 @@ private void QuickSortIndicesInPlace(GrowingArray<TKey> keys, List<TInputOutput>
         // negatively impact speedups.
         //
 
-#if !FEATURE_WASM_THREADS
+#if !FEATURE_WASM_MANAGED_THREADS
         [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
 #endif
         private void MergeSortCooperatively()

src/libraries/System.Linq.Parallel/src/System/Linq/ParallelEnumerable.cs

@@ -64,7 +64,7 @@ public static class ParallelEnumerable
 
         // When running in single partition mode, PLINQ operations will occur on a single partition and will not
         // be executed in parallel, but will retain PLINQ semantics (exceptions wrapped as aggregates, etc).
-#if !FEATURE_WASM_THREADS
+#if !FEATURE_WASM_MANAGED_THREADS
         [System.Runtime.Versioning.SupportedOSPlatformGuard("browser")]
         internal static bool SinglePartitionMode => OperatingSystem.IsBrowser();
 #else

src/libraries/System.Net.Http/src/System.Net.Http.csproj

@@ -11,7 +11,7 @@
   <PropertyGroup>
     <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
     <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.PlatformNotSupported_NetHttp</GeneratePlatformNotSupportedAssemblyMessage>
-    <FeatureWasmThreads Condition="'$(TargetPlatformIdentifier)' == 'browser' and '$(MonoWasmBuildVariant)' == 'multithread'">true</FeatureWasmThreads>
+    <FeatureWasmManagedThreads Condition="'$(TargetPlatformIdentifier)' == 'browser' and '$(WasmEnableThreads)' == 'true'">true</FeatureWasmManagedThreads>
     <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'osx' or '$(TargetPlatformIdentifier)' == 'ios' or '$(TargetPlatformIdentifier)' == 'tvos' or '$(TargetPlatformIdentifier)' == 'maccatalyst'">$(DefineConstants);SYSNETHTTP_NO_OPENSSL</DefineConstants>
     <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'android' or '$(TargetPlatformIdentifier)' == 'ios' or '$(TargetPlatformIdentifier)' == 'maccatalyst' or '$(TargetPlatformIdentifier)' == 'tvos'">$(DefineConstants);TARGET_MOBILE</DefineConstants>
     <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'android'">$(DefineConstants);TARGET_ANDROID</DefineConstants>
@@ -20,7 +20,7 @@
     <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'tvos'">$(DefineConstants);TARGET_TVOS</DefineConstants>
     <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'browser'">$(DefineConstants);TARGET_BROWSER</DefineConstants>
     <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'wasi'">$(DefineConstants);TARGET_WASI</DefineConstants>
-    <DefineConstants Condition="'$(FeatureWasmThreads)' == 'true'" >$(DefineConstants);FEATURE_WASM_THREADS</DefineConstants>
+    <DefineConstants Condition="'$(FeatureWasmManagedThreads)' == 'true'" >$(DefineConstants);FEATURE_WASM_MANAGED_THREADS</DefineConstants>
     <EmitCompilerGeneratedFiles Condition="'$(Configuration)' == 'Debug' and '$(TargetPlatformIdentifier)' == 'browser'">true</EmitCompilerGeneratedFiles>
   </PropertyGroup>
 

src/libraries/System.Net.WebSockets.Client/src/System.Net.WebSockets.Client.csproj

@@ -9,9 +9,9 @@
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>
     <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
-    <FeatureWasmThreads Condition="'$(TargetPlatformIdentifier)' == 'browser' and '$(MonoWasmBuildVariant)' == 'multithread'">true</FeatureWasmThreads>
+    <FeatureWasmManagedThreads Condition="'$(TargetPlatformIdentifier)' == 'browser' and '$(WasmEnableThreads)' == 'true'">true</FeatureWasmManagedThreads>
     <DefineConstants Condition="'$(TargetPlatformIdentifier)' == 'browser'">$(DefineConstants);TARGET_BROWSER</DefineConstants>
-    <DefineConstants Condition="'$(FeatureWasmThreads)' == 'true'" >$(DefineConstants);FEATURE_WASM_THREADS</DefineConstants>
+    <DefineConstants Condition="'$(FeatureWasmManagedThreads)' == 'true'" >$(DefineConstants);FEATURE_WASM_MANAGED_THREADS</DefineConstants>
     <EmitCompilerGeneratedFiles Condition="'$(Configuration)' == 'Debug' and '$(TargetPlatformIdentifier)' == 'browser'">true</EmitCompilerGeneratedFiles>
   </PropertyGroup>