App-vNext · martincostello · Aug 12, 2025 · Aug 12, 2025 · Aug 14, 2025 · Sep 9, 2025
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -85,6 +85,7 @@ jobs:
       with:
         dotnet-version: |
           8.0.x
+          9.0.x
 
     - name: Setup .NET SDK
       uses: actions/setup-dotnet@d4c94342e560b34958eacfc5d055d21461ed1c5d # v5.0.0

diff --git a/.github/workflows/mutation-tests.yml b/.github/workflows/mutation-tests.yml
@@ -59,6 +59,7 @@ jobs:
       with:
         dotnet-version: |
           8.0.x
+          9.0.x
 
     - name: Setup .NET SDK
       uses: actions/setup-dotnet@d4c94342e560b34958eacfc5d055d21461ed1c5d # v5.0.0

diff --git a/Directory.Build.props b/Directory.Build.props
@@ -7,4 +7,8 @@
     <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
     <Deterministic>true</Deterministic>
   </PropertyGroup>
+  <!-- HACK Workaround for https://github.com/dotnet/sdk/issues/51265 -->
+  <PropertyGroup>
+    <RestoreEnablePackagePruning>false</RestoreEnablePackagePruning>
+  </PropertyGroup>
 </Project>
diff --git a/Directory.Packages.props b/Directory.Packages.props
@@ -35,7 +35,6 @@
     <PackageVersion Include="SonarAnalyzer.CSharp" Version="10.15.0.120848" />
     <PackageVersion Include="StyleCop.Analyzers" Version="1.2.0-beta.556" />
     <PackageVersion Include="System.ComponentModel.Annotations" Version="4.5.0" />
-    <PackageVersion Include="System.Text.Json" Version="9.0.8" />
     <PackageVersion Include="System.Threading.Tasks.Extensions" Version="4.5.4" />
     <PackageVersion Include="System.ValueTuple" Version="4.5.0" />
     <PackageVersion Include="xunit" Version="2.9.3" />
@@ -58,4 +57,12 @@
     <PackageVersion Update="System.Diagnostics.DiagnosticSource" Version="9.0.0" />
     <PackageVersion Update="System.Threading.RateLimiting" Version="9.0.0" />
   </ItemGroup>
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible($(TargetFramework), 'net10.0'))">
+    <PackageVersion Update="Microsoft.Bcl.TimeProvider" Version="10.0.0-rc.2.25502.107" />
+    <PackageVersion Update="Microsoft.Extensions.Logging" Version="10.0.0-rc.2.25502.107" />
+    <PackageVersion Update="Microsoft.Extensions.Logging.Abstractions" Version="10.0.0-rc.2.25502.107" />
+    <PackageVersion Update="Microsoft.Extensions.Options" Version="10.0.0-rc.2.25502.107" />
+    <PackageVersion Update="System.Diagnostics.DiagnosticSource" Version="10.0.0-rc.2.25502.107" />
+    <PackageVersion Update="System.Threading.RateLimiting" Version="10.0.0-rc.2.25502.107" />
+  </ItemGroup>
 </Project>
diff --git a/bench/Polly.Benchmarks/Polly.Benchmarks.csproj b/bench/Polly.Benchmarks/Polly.Benchmarks.csproj
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <IsPackable>false</IsPackable>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks>net10.0;net9.0;net8.0</TargetFrameworks>
     <Nullable>enable</Nullable>
     <ProjectType>Benchmark</ProjectType>
     <NoWarn>$(NoWarn);CA1822;IDE0060</NoWarn>

diff --git a/bench/Polly.Core.Benchmarks/Polly.Core.Benchmarks.csproj b/bench/Polly.Core.Benchmarks/Polly.Core.Benchmarks.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net9.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net10.0;net9.0;net8.0</TargetFrameworks>
     <RootNamespace>Polly</RootNamespace>
     <ImplicitUsings>true</ImplicitUsings>
     <ProjectType>Benchmark</ProjectType>

diff --git a/bench/benchmarks.ps1 b/bench/benchmarks.ps1
@@ -20,6 +20,6 @@ if ($Interactive -ne $true) {
 
 $project = Join-Path "Polly.Core.Benchmarks" "Polly.Core.Benchmarks.csproj"
 
-dotnet run --configuration $Configuration --framework net9.0 --project $project $additionalArgs
+dotnet run --configuration $Configuration --framework net10.0 --project $project $additionalArgs
 
 exit $LASTEXITCODE
diff --git a/build.ps1 b/build.ps1
@@ -25,7 +25,7 @@ https://cakebuild.net
 #>
 
 Param(
-    [string]$Script = "build.cake",
+    [string]$Script = "cake.cs",
     [string]$Target = "Default",
     [ValidateSet("Default", "MutationCore", "MutationLegacy")]
     [string]$Configuration = "Release",
@@ -82,6 +82,6 @@ if ($WhatIf.IsPresent) {
 # Start Cake
 Write-Output "Running build script..."
 
-& dotnet cake $Script "--target=$Target" "--configuration=$Configuration" "--verbosity=$Verbosity" $additionalArgs
+& dotnet $Script -- "--target=$Target" "--configuration=$Configuration" "--verbosity=$Verbosity" $additionalArgs
 
 exit $LASTEXITCODE
diff --git a/build.cake → cake.cs b/build.cake → cake.cs
@@ -1,17 +1,16 @@
+#:sdk Cake.Sdk
+#:package Cake.FileHelpers
+#:package Newtonsoft.Json
+#:property ProjectType=Test
+#:property SignAssembly=false
+
 ///////////////////////////////////////////////////////////////////////////////
 // ARGUMENTS
 ///////////////////////////////////////////////////////////////////////////////
 
 var target = Argument<string>("target", "Default");
 var configuration = Argument<string>("configuration", "Release");
 
-//////////////////////////////////////////////////////////////////////
-// EXTERNAL NUGET LIBRARIES
-//////////////////////////////////////////////////////////////////////
-
-#addin nuget:?package=Cake.FileHelpers&version=7.0.0
-#addin nuget:?package=Newtonsoft.Json&version=13.0.3
-
 ///////////////////////////////////////////////////////////////////////////////
 // GLOBAL VARIABLES
 ///////////////////////////////////////////////////////////////////////////////
@@ -285,11 +284,6 @@
 // HELPER FUNCTIONS
 //////////////////////////////////////////////////////////////////////
 
-string ToolsExePath(string exeFileName) {
-    var exePath = System.IO.Directory.GetFiles("./tools", exeFileName, SearchOption.AllDirectories).FirstOrDefault();
-    return exePath;
-}
-
 string PatchStrykerConfig(string path, Action<Newtonsoft.Json.Linq.JObject> patch)
 {
     var json = System.IO.File.ReadAllText(path);

diff --git a/eng/stryker-config.json b/eng/stryker-config.json
@@ -21,7 +21,8 @@
     ],
     "concurrency": 4,
     "configuration": "Debug",
-    "target-framework": "net8.0",
+    "language-version": "Preview",
+    "target-framework": "net10.0",
     "thresholds": {
       "high": 100,
       "low": 100

diff --git a/global.json b/global.json
@@ -1,7 +1,10 @@
 {
   "sdk": {
-    "version": "9.0.306",
+    "version": "10.0.100-rc.2.25502.107",
     "allowPrerelease": false,
     "rollForward": "latestMajor"
+  },
+  "msbuild-sdks": {
+    "Cake.Sdk": "5.0.25257.82-beta"
   }
 }
diff --git a/samples/Chaos/Chaos.csproj b/samples/Chaos/Chaos.csproj
@@ -1,14 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <RootNamespace>Chaos</RootNamespace>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Http.Resilience" />
     <PackageReference Include="Polly.Core" />
-    <PackageReference Include="System.Text.Json" />
   </ItemGroup>
 
 </Project>
diff --git a/samples/DependencyInjection/DependencyInjection.csproj b/samples/DependencyInjection/DependencyInjection.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/samples/Extensibility/Extensibility.csproj b/samples/Extensibility/Extensibility.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/samples/GenericPipelines/GenericPipelines.csproj b/samples/GenericPipelines/GenericPipelines.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/samples/Intro/Intro.csproj b/samples/Intro/Intro.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/samples/Retries/Retries.csproj b/samples/Retries/Retries.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/src/Polly/Bulkhead/AsyncBulkheadPolicy.cs b/src/Polly/Bulkhead/AsyncBulkheadPolicy.cs
@@ -10,20 +10,21 @@ public class AsyncBulkheadPolicy : AsyncPolicy, IBulkheadPolicy
 {
     private readonly SemaphoreSlim _maxParallelizationSemaphore;
     private readonly SemaphoreSlim _maxQueuedActionsSemaphore;
-    private readonly int _maxQueueingActions;
     private readonly Func<Context, Task> _onBulkheadRejectedAsync;
 
     internal AsyncBulkheadPolicy(
         int maxParallelization,
         int maxQueueingActions,
         Func<Context, Task> onBulkheadRejectedAsync)
     {
-        _maxQueueingActions = maxQueueingActions;
+        MaxQueueingActions = maxQueueingActions;
         _onBulkheadRejectedAsync = onBulkheadRejectedAsync;
 
         (_maxParallelizationSemaphore, _maxQueuedActionsSemaphore) = BulkheadSemaphoreFactory.CreateBulkheadSemaphores(maxParallelization, maxQueueingActions);
     }
 
+    private int MaxQueueingActions { get; }
+
     /// <summary>
     /// Gets the number of slots currently available for executing actions through the bulkhead.
     /// </summary>
@@ -32,7 +33,7 @@ internal AsyncBulkheadPolicy(
     /// <summary>
     /// Gets the number of slots currently available for queuing actions for execution through the bulkhead.
     /// </summary>
-    public int QueueAvailableCount => Math.Min(_maxQueuedActionsSemaphore.CurrentCount, _maxQueueingActions);
+    public int QueueAvailableCount => Math.Min(_maxQueuedActionsSemaphore.CurrentCount, MaxQueueingActions);
 
     /// <inheritdoc/>
     [DebuggerStepThrough]
@@ -78,20 +79,21 @@ public class AsyncBulkheadPolicy<TResult> : AsyncPolicy<TResult>, IBulkheadPolic
 {
     private readonly SemaphoreSlim _maxParallelizationSemaphore;
     private readonly SemaphoreSlim _maxQueuedActionsSemaphore;
-    private readonly int _maxQueueingActions;
     private readonly Func<Context, Task> _onBulkheadRejectedAsync;
 
     internal AsyncBulkheadPolicy(
         int maxParallelization,
         int maxQueueingActions,
         Func<Context, Task> onBulkheadRejectedAsync)
     {
-        _maxQueueingActions = maxQueueingActions;
+        MaxQueueingActions = maxQueueingActions;
         _onBulkheadRejectedAsync = onBulkheadRejectedAsync;
 
         (_maxParallelizationSemaphore, _maxQueuedActionsSemaphore) = BulkheadSemaphoreFactory.CreateBulkheadSemaphores(maxParallelization, maxQueueingActions);
     }
 
+    private int MaxQueueingActions { get; }
+
     /// <inheritdoc/>
     [DebuggerStepThrough]
     protected override Task<TResult> ImplementationAsync(
@@ -123,7 +125,7 @@ protected override Task<TResult> ImplementationAsync(
     /// <summary>
     /// Gets the number of slots currently available for queuing actions for execution through the bulkhead.
     /// </summary>
-    public int QueueAvailableCount => Math.Min(_maxQueuedActionsSemaphore.CurrentCount, _maxQueueingActions);
+    public int QueueAvailableCount => Math.Min(_maxQueuedActionsSemaphore.CurrentCount, MaxQueueingActions);
 
 #pragma warning disable CA1063
     /// <inheritdoc/>

diff --git a/src/Polly/Bulkhead/BulkheadPolicy.cs b/src/Polly/Bulkhead/BulkheadPolicy.cs
@@ -10,20 +10,21 @@ public class BulkheadPolicy : Policy, IBulkheadPolicy
 {
     private readonly SemaphoreSlim _maxParallelizationSemaphore;
     private readonly SemaphoreSlim _maxQueuedActionsSemaphore;
-    private readonly int _maxQueueingActions;
     private readonly Action<Context> _onBulkheadRejected;
 
     internal BulkheadPolicy(
         int maxParallelization,
         int maxQueueingActions,
         Action<Context> onBulkheadRejected)
     {
-        _maxQueueingActions = maxQueueingActions;
+        MaxQueueingActions = maxQueueingActions;
         _onBulkheadRejected = onBulkheadRejected;
 
         (_maxParallelizationSemaphore, _maxQueuedActionsSemaphore) = BulkheadSemaphoreFactory.CreateBulkheadSemaphores(maxParallelization, maxQueueingActions);
     }
 
+    private int MaxQueueingActions { get; }
+
     /// <inheritdoc/>
     [DebuggerStepThrough]
     protected override TResult Implementation<TResult>(Func<Context, CancellationToken, TResult> action, Context context, CancellationToken cancellationToken)
@@ -50,7 +51,7 @@ protected override TResult Implementation<TResult>(Func<Context, CancellationTok
     /// <summary>
     /// Gets the number of slots currently available for queuing actions for execution through the bulkhead.
     /// </summary>
-    public int QueueAvailableCount => Math.Min(_maxQueuedActionsSemaphore.CurrentCount, _maxQueueingActions);
+    public int QueueAvailableCount => Math.Min(_maxQueuedActionsSemaphore.CurrentCount, MaxQueueingActions);
 
 #pragma warning disable CA1063
     /// <summary>
@@ -76,20 +77,21 @@ public class BulkheadPolicy<TResult> : Policy<TResult>, IBulkheadPolicy<TResult>
 {
     private readonly SemaphoreSlim _maxParallelizationSemaphore;
     private readonly SemaphoreSlim _maxQueuedActionsSemaphore;
-    private readonly int _maxQueueingActions;
     private readonly Action<Context> _onBulkheadRejected;
 
     internal BulkheadPolicy(
         int maxParallelization,
         int maxQueueingActions,
         Action<Context> onBulkheadRejected)
     {
-        _maxQueueingActions = maxQueueingActions;
+        MaxQueueingActions = maxQueueingActions;
         _onBulkheadRejected = onBulkheadRejected;
 
         (_maxParallelizationSemaphore, _maxQueuedActionsSemaphore) = BulkheadSemaphoreFactory.CreateBulkheadSemaphores(maxParallelization, maxQueueingActions);
     }
 
+    private int MaxQueueingActions { get; }
+
     /// <inheritdoc/>
     [DebuggerStepThrough]
     protected override TResult Implementation(Func<Context, CancellationToken, TResult> action, Context context, CancellationToken cancellationToken)
@@ -115,7 +117,7 @@ protected override TResult Implementation(Func<Context, CancellationToken, TResu
     /// <summary>
     /// Gets the number of slots currently available for queuing actions for execution through the bulkhead.
     /// </summary>
-    public int QueueAvailableCount => Math.Min(_maxQueuedActionsSemaphore.CurrentCount, _maxQueueingActions);
+    public int QueueAvailableCount => Math.Min(_maxQueuedActionsSemaphore.CurrentCount, MaxQueueingActions);
 
 #pragma warning disable CA1063
     /// <summary>

diff --git a/src/Polly/Context.Dictionary.cs b/src/Polly/Context.Dictionary.cs
@@ -11,9 +11,11 @@ public partial class Context : IDictionary<string, object>, IDictionary, IReadOn
     // For an individual execution through a policy or policywrap, it is expected that all execution steps (for example executing the user delegate, invoking policy-activity delegates such as onRetry, onBreak, onTimeout etc) execute sequentially.
     // Therefore, this class is intentionally not constructed to be safe for concurrent access from multiple threads.
 
-    private Dictionary<string, object> _wrappedDictionary;
-
-    private Dictionary<string, object> WrappedDictionary => _wrappedDictionary ?? (_wrappedDictionary = []);
+    private Dictionary<string, object> WrappedDictionary
+    {
+        get => field ??= [];
+        set;
+    }
 
     /// <summary>
     /// Initializes a new instance of the <see cref="Context"/> class, with the specified <paramref name="operationKey" /> and the supplied <paramref name="contextData"/>.
@@ -32,7 +34,7 @@ internal Context(IDictionary<string, object> contextData)
             throw new ArgumentNullException(nameof(contextData));
         }
 
-        _wrappedDictionary = new Dictionary<string, object>(contextData);
+        WrappedDictionary = new Dictionary<string, object>(contextData);
     }
 
     #region IDictionary<string,object> implementation

diff --git a/src/Snippets/Snippets.csproj b/src/Snippets/Snippets.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <ProjectType>Library</ProjectType>
@@ -29,7 +29,6 @@
     <PackageReference Include="NSubstitute" />
     <PackageReference Include="Refit.HttpClientFactory" />
     <PackageReference Include="RestSharp" />
-    <PackageReference Include="System.Text.Json" />
     <PackageReference Include="xunit" />
   </ItemGroup>
 

diff --git a/test/Polly.AotTest/Polly.AotTest.csproj b/test/Polly.AotTest/Polly.AotTest.csproj
@@ -5,7 +5,7 @@
     <PublishAot>true</PublishAot>
     <SKIP_POLLY_ANALYZERS>true</SKIP_POLLY_ANALYZERS>
     <SelfContained>true</SelfContained>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\src\Polly.Core\Polly.Core.csproj" />

diff --git a/test/Polly.Core.Tests/Polly.Core.Tests.csproj b/test/Polly.Core.Tests/Polly.Core.Tests.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net9.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net10.0;net9.0;net8.0</TargetFrameworks>
     <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('Windows'))">$(TargetFrameworks);net481</TargetFrameworks>
     <TestTfmsInParallel Condition="$([MSBuild]::IsOSPlatform('Windows'))">false</TestTfmsInParallel>
     <ProjectType>Test</ProjectType>
-Original file line number
+Diff line change
@@ Expand Up / @@ -85,6 +85,7 @@ jobs: @@
           with:
             dotnet-version: |
 .0.x
+.0.x
         - name: Setup .NET SDK
           uses: actions/setup-dotnet@d4c94342e560b34958eacfc5d055d21461ed1c5d # v5.0.0
@@ Expand Down @@