Add cancellation token parameter to async feature management interfaces.

examples/ConsoleApp/FeatureFilters/AccountIdFilter.cs

@@ -6,6 +6,7 @@
 using Microsoft.FeatureManagement;
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Consoto.Banking.AccountService.FeatureManagement
@@ -17,7 +18,7 @@ namespace Consoto.Banking.AccountService.FeatureManagement
     [FilterAlias("AccountId")]
     class AccountIdFilter : IContextualFeatureFilter<IAccountContext>
     {
-        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext featureEvaluationContext, IAccountContext accountContext)
+        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext featureEvaluationContext, IAccountContext accountContext, CancellationToken _)
         {
             if (string.IsNullOrEmpty(accountContext?.AccountId))
             {

examples/ConsoleApp/Program.cs

@@ -8,6 +8,7 @@
 using Microsoft.FeatureManagement.FeatureFilters;
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Consoto.Banking.AccountService
@@ -58,7 +59,7 @@ public static async Task Main(string[] args)
                         AccountId = account
                     };
 
-                    bool enabled = await featureManager.IsEnabledAsync(FeatureName, accountServiceContext);
+                    bool enabled = await featureManager.IsEnabledAsync(FeatureName, accountServiceContext, CancellationToken.None);
 
                     //
                     // Output results

examples/FeatureFlagDemo/BrowserFilter.cs

@@ -6,6 +6,7 @@
 using Microsoft.FeatureManagement;
 using System;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace FeatureFlagDemo.FeatureManagement.FeatureFilters
@@ -23,7 +24,7 @@ public BrowserFilter(IHttpContextAccessor httpContextAccessor)
             _httpContextAccessor = httpContextAccessor ?? throw new ArgumentNullException(nameof(httpContextAccessor));
         }
 
-        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context)
+        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context, CancellationToken _)
         {
             BrowserFilterSettings settings = context.Parameters.Get<BrowserFilterSettings>() ?? new BrowserFilterSettings();
 

examples/FeatureFlagDemo/Controllers/HomeController.cs

@@ -8,6 +8,7 @@
 using Microsoft.FeatureManagement;
 using Microsoft.FeatureManagement.Mvc;
 using System.Threading.Tasks;
+using System.Threading;
 
 namespace FeatureFlagDemo.Controllers
 {
@@ -26,11 +27,11 @@ public IActionResult Index()
             return View();
         }
 
-        public async Task<IActionResult> About()
+        public async Task<IActionResult> About(CancellationToken cancellationToken)
         {
             ViewData["Message"] = "Your application description page.";
 
-            if (await _featureManager.IsEnabledAsync(nameof(MyFeatureFlags.CustomViewData)))
+            if (await _featureManager.IsEnabledAsync(nameof(MyFeatureFlags.CustomViewData), cancellationToken))
             {
                 ViewData["Message"] = $"This is FANCY CONTENT you can see only if '{nameof(MyFeatureFlags.CustomViewData)}' is enabled.";
             };

examples/FeatureFlagDemo/HttpContextTargetingContextAccessor.cs

@@ -6,6 +6,7 @@
 using System;
 using System.Collections.Generic;
 using System.Security.Claims;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace FeatureFlagDemo
@@ -23,7 +24,7 @@ public HttpContextTargetingContextAccessor(IHttpContextAccessor httpContextAcces
             _httpContextAccessor = httpContextAccessor ?? throw new ArgumentNullException(nameof(httpContextAccessor));
         }
 
-        public ValueTask<TargetingContext> GetContextAsync()
+        public ValueTask<TargetingContext> GetContextAsync(CancellationToken _)
         {
             HttpContext httpContext = _httpContextAccessor.HttpContext;
 

examples/FeatureFlagDemo/SuperUserFilter.cs

@@ -2,13 +2,14 @@
 // Licensed under the MIT license.
 //
 using Microsoft.FeatureManagement;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace FeatureFlagDemo.FeatureManagement.FeatureFilters
 {
     public class SuperUserFilter : IFeatureFilter
     {
-        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context)
+        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context, CancellationToken _)
         {
             return Task.FromResult(false);
         }

examples/TargetingConsoleApp/Program.cs

@@ -9,6 +9,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Consoto.Banking.HelpDesk
@@ -62,7 +63,7 @@ public static async Task Main(string[] args)
                         Groups = user.Groups
                     };
 
-                    bool enabled = await featureManager.IsEnabledAsync(FeatureName, targetingContext);
+                    bool enabled = await featureManager.IsEnabledAsync(FeatureName, targetingContext, CancellationToken.None);
 
                     //
                     // Output results

src/Microsoft.FeatureManagement.AspNetCore/FeatureGateAttribute.cs

@@ -106,8 +106,8 @@ public override async Task OnActionExecutionAsync(ActionExecutingContext context
             //
             // Enabled state is determined by either 'any' or 'all' features being enabled.
             bool enabled = RequirementType == RequirementType.All ?
-                             await Features.All(async feature => await fm.IsEnabledAsync(feature).ConfigureAwait(false)) :
-                             await Features.Any(async feature => await fm.IsEnabledAsync(feature).ConfigureAwait(false));
+                             await Features.All(async feature => await fm.IsEnabledAsync(feature, context.HttpContext.RequestAborted).ConfigureAwait(false)).ConfigureAwait(false) :
+                             await Features.Any(async feature => await fm.IsEnabledAsync(feature, context.HttpContext.RequestAborted).ConfigureAwait(false)).ConfigureAwait(false);
 
             if (enabled)
             {

src/Microsoft.FeatureManagement.AspNetCore/FeatureGatedAsyncActionFilter.cs

@@ -30,7 +30,7 @@ public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionE
         {
             IFeatureManager featureManager = context.HttpContext.RequestServices.GetRequiredService<IFeatureManagerSnapshot>();
 
-            if (await featureManager.IsEnabledAsync(FeatureName).ConfigureAwait(false))
+            if (await featureManager.IsEnabledAsync(FeatureName, context.HttpContext.RequestAborted).ConfigureAwait(false))
             {
                 IServiceProvider serviceProvider = context.HttpContext.RequestServices.GetRequiredService<IServiceProvider>();
 

src/Microsoft.FeatureManagement.AspNetCore/TagHelpers/FeatureTagHelper.cs

@@ -4,6 +4,7 @@
 using Microsoft.AspNetCore.Razor.TagHelpers;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Microsoft.FeatureManagement.Mvc.TagHelpers
@@ -55,8 +56,8 @@ public override async Task ProcessAsync(TagHelperContext context, TagHelperOutpu
                 IEnumerable<string> names = Name.Split(',').Select(n => n.Trim());
 
                 enabled = Requirement == RequirementType.All ?
-                    await names.All(async n => await _featureManager.IsEnabledAsync(n).ConfigureAwait(false)) :
-                    await names.Any(async n => await _featureManager.IsEnabledAsync(n).ConfigureAwait(false));
+                    await names.All(async n => await _featureManager.IsEnabledAsync(n, CancellationToken.None).ConfigureAwait(false)).ConfigureAwait(false) :
+                    await names.Any(async n => await _featureManager.IsEnabledAsync(n, CancellationToken.None).ConfigureAwait(false)).ConfigureAwait(false);
             }
 
             if (Negate)

src/Microsoft.FeatureManagement.AspNetCore/UseForFeatureExtensions.cs

@@ -57,7 +57,7 @@ public static IApplicationBuilder UseForFeature(this IApplicationBuilder app, st
                 {
                     IFeatureManager fm = context.RequestServices.GetRequiredService<IFeatureManagerSnapshot>();
 
-                    if (await fm.IsEnabledAsync(featureName).ConfigureAwait(false))
+                    if (await fm.IsEnabledAsync(featureName, context.RequestAborted).ConfigureAwait(false))
                     {
                         await branch(context).ConfigureAwait(false);
                     }

src/Microsoft.FeatureManagement/ConfigurationFeatureDefinitionProvider.cs

@@ -7,6 +7,7 @@
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -40,7 +41,7 @@ public void Dispose()
             _changeSubscription = null;
         }
 
-        public Task<FeatureDefinition> GetFeatureDefinitionAsync(string featureName)
+        public Task<FeatureDefinition> GetFeatureDefinitionAsync(string featureName, CancellationToken _)
         {
             if (featureName == null)
             {
@@ -63,7 +64,7 @@ public Task<FeatureDefinition> GetFeatureDefinitionAsync(string featureName)
         // The async key word is necessary for creating IAsyncEnumerable.
         // The need to disable this warning occurs when implementaing async stream synchronously. 
 #pragma warning disable CS1998 // Async method lacks 'await' operators and will run synchronously
-        public async IAsyncEnumerable<FeatureDefinition> GetAllFeatureDefinitionsAsync()
+        public async IAsyncEnumerable<FeatureDefinition> GetAllFeatureDefinitionsAsync([EnumeratorCancellation] CancellationToken _)
 #pragma warning restore CS1998
         {
             if (Interlocked.Exchange(ref _stale, 0) != 0)

src/Microsoft.FeatureManagement/ContextualFeatureFilterEvaluator.cs

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Microsoft.FeatureManagement
@@ -15,7 +16,7 @@ namespace Microsoft.FeatureManagement
     class ContextualFeatureFilterEvaluator : IContextualFeatureFilter<object>
     {
         private IFeatureFilterMetadata _filter;
-        private Func<object, FeatureFilterEvaluationContext, object, Task<bool>> _evaluateFunc;
+        private Func<object, FeatureFilterEvaluationContext, object, CancellationToken, Task<bool>> _evaluateFunc;
 
         public ContextualFeatureFilterEvaluator(IFeatureFilterMetadata filter, Type appContextType)
         {
@@ -43,14 +44,14 @@ public ContextualFeatureFilterEvaluator(IFeatureFilterMetadata filter, Type appC
             _filter = filter;
         }
 
-        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext evaluationContext, object context)
+        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext evaluationContext, object context, CancellationToken cancellationToken)
         {
             if (_evaluateFunc == null)
             {
                 return Task.FromResult(false);
             }
 
-            return _evaluateFunc(_filter, evaluationContext, context);
+            return _evaluateFunc(_filter, evaluationContext, context, cancellationToken);
         }
 
         public static bool IsContextualFilter(IFeatureFilterMetadata filter, Type appContextType)
@@ -72,7 +73,7 @@ private static Type GetContextualFilterInterface(IFeatureFilterMetadata filter,
             return targetInterface;
         }
 
-        private static Func<object, FeatureFilterEvaluationContext, object, Task<bool>> TypeAgnosticEvaluate(Type filterType, MethodInfo method)
+        private static Func<object, FeatureFilterEvaluationContext, object, CancellationToken, Task<bool>> TypeAgnosticEvaluate(Type filterType, MethodInfo method)
         {
             //
             // Get the generic version of the evaluation helper method
@@ -82,23 +83,30 @@ private static Func<object, FeatureFilterEvaluationContext, object, Task<bool>>
             //
             // Create a type specific version of the evaluation helper method
             MethodInfo constructedHelper = genericHelper.MakeGenericMethod
-                (filterType, method.GetParameters()[0].ParameterType, method.GetParameters()[1].ParameterType, method.ReturnType);
+                (filterType,
+                 method.GetParameters()[0].ParameterType,
+                 method.GetParameters()[1].ParameterType,
+                 method.GetParameters()[2].ParameterType,
+                 method.ReturnType);
 
             //
             // Invoke the method to get the func
             object typeAgnosticDelegate = constructedHelper.Invoke(null, new object[] { method });
 
-            return (Func<object, FeatureFilterEvaluationContext, object, Task<bool>>)typeAgnosticDelegate;
+            return (Func<object, FeatureFilterEvaluationContext, object, CancellationToken, Task<bool>>)typeAgnosticDelegate;
         }
 
-        private static Func<object, FeatureFilterEvaluationContext, object, Task<bool>> GenericTypeAgnosticEvaluate<TTarget, TParam1, TParam2, TReturn>(MethodInfo method)
+        private static Func<object, FeatureFilterEvaluationContext, object, CancellationToken, Task<bool>> GenericTypeAgnosticEvaluate<TTarget, TParam1, TParam2, TParam3, TReturn>(MethodInfo method)
         {
-            Func<TTarget, FeatureFilterEvaluationContext, TParam2, Task<bool>> func = (Func<TTarget, FeatureFilterEvaluationContext, TParam2, Task<bool>>)Delegate.CreateDelegate
-                (typeof(Func<TTarget, FeatureFilterEvaluationContext, TParam2, Task<bool>>), method);
+            Func<TTarget, FeatureFilterEvaluationContext, TParam2, CancellationToken, Task<bool>> func =
+                (Func<TTarget, FeatureFilterEvaluationContext, TParam2, CancellationToken, Task<bool>>)
+                Delegate.CreateDelegate(typeof(Func<TTarget, FeatureFilterEvaluationContext, TParam2, CancellationToken, Task<bool>>), method);
 
-            Func<object, FeatureFilterEvaluationContext, object, Task<bool>> genericDelegate = (object target, FeatureFilterEvaluationContext param1, object param2) => func((TTarget)target, param1, (TParam2)param2);
+            Func<object, FeatureFilterEvaluationContext, object, CancellationToken, Task<bool>> genericDelegate =
+                (object target, FeatureFilterEvaluationContext param1, object param2, CancellationToken param3) =>
+                    func((TTarget)target, param1, (TParam2)param2, param3);
 
             return genericDelegate;
         }
     }
-}
+}

src/Microsoft.FeatureManagement/EmptySessionManager.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT license.
 //
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Microsoft.FeatureManagement
@@ -10,12 +11,12 @@ namespace Microsoft.FeatureManagement
     /// </summary>
     class EmptySessionManager : ISessionManager
     {
-        public Task SetAsync(string featureName, bool enabled)
+        public Task SetAsync(string featureName, bool enabled, CancellationToken _)
         {
             return Task.CompletedTask;
         }
 
-        public Task<bool?> GetAsync(string featureName)
+        public Task<bool?> GetAsync(string featureName, CancellationToken _)
         {
             return Task.FromResult((bool?)null);
         }

src/Microsoft.FeatureManagement/FeatureFilters/PercentageFilter.cs

@@ -4,6 +4,7 @@
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Logging;
 using Microsoft.FeatureManagement.Utils;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Microsoft.FeatureManagement.FeatureFilters
@@ -30,8 +31,9 @@ public PercentageFilter(ILoggerFactory loggerFactory)
         /// Performs a percentage based evaluation to determine whether a feature is enabled.
         /// </summary>
         /// <param name="context">The feature evaluation context.</param>
+        /// <param name="cancellationToken">The cancellation token to cancel the operation.</param>
         /// <returns>True if the feature is enabled, false otherwise.</returns>
-        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context)
+        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context, CancellationToken cancellationToken)
         {
             PercentageFilterSettings settings = context.Parameters.Get<PercentageFilterSettings>() ?? new PercentageFilterSettings();
 

src/Microsoft.FeatureManagement/FeatureFilters/TimeWindowFilter.cs

@@ -4,6 +4,7 @@
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Logging;
 using System;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Microsoft.FeatureManagement.FeatureFilters
@@ -30,8 +31,9 @@ public TimeWindowFilter(ILoggerFactory loggerFactory)
         /// Evaluates whether a feature is enabled based on a configurable time window.
         /// </summary>
         /// <param name="context">The feature evaluation context.</param>
+        /// <param name="cancellationToken">The cancellation token to cancel the operation.</param>
         /// <returns>True if the feature is enabled, false otherwise.</returns>
-        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context)
+        public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context, CancellationToken cancellationToken)
         {
             TimeWindowFilterSettings settings = context.Parameters.Get<TimeWindowFilterSettings>() ?? new TimeWindowFilterSettings();