Fix the behavior of OnHedging event

src/Polly.Core/Hedging/Controller/TaskExecution.cs

@@ -148,9 +148,9 @@ private async Task HandleOnHedgingAsync(ResilienceContext primaryContext, int at
 
         _telemetry.Report(new(ResilienceEventSeverity.Warning, HedgingConstants.OnHedgingEventName), Context, args);
 
-        if (_handler.OnHedging is not null)
+        if (_handler.OnHedging is { } onHedging)
         {
-            await _handler.OnHedging(args).ConfigureAwait(Context.ContinueOnCapturedContext);
+            await onHedging(args).ConfigureAwait(Context.ContinueOnCapturedContext);
         }
     }
 

src/Polly.Core/Hedging/HedgingActionGeneratorArguments.cs

@@ -7,17 +7,20 @@ namespace Polly.Hedging;
 /// </summary>
 /// <typeparam name="TResult">The type of the result.</typeparam>
 /// <remarks>
+/// The <see cref="PrimaryContext"/> represents the context that was received by the hedging strategy and used to execute the primary action.
+/// To prevent race conditions, hedging strategy then clones the primary context into <see cref="ActionContext"/> and uses it to execute the hedged action.
+/// Every hedged action gets its own context that is cloned from primary.
+/// <para>
 /// Always use the constructor when creating this struct, otherwise we do not guarantee binary compatibility.
+/// </para>
 /// </remarks>
 public readonly struct HedgingActionGeneratorArguments<TResult>
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="HedgingActionGeneratorArguments{TResult}"/> struct.
     /// </summary>
-    /// <param name="primaryContext">The primary resilience context.</param>
-    /// <param name="actionContext">
-    /// The context that will be passed to action generated by <see cref="HedgingStrategyOptions{TResult}.ActionGenerator"/>.
-    /// .</param>
+    /// <param name="primaryContext">The primary context received by hedging strategy.</param>
+    /// <param name="actionContext">The action context. cloned from the primary context.</param>
     /// <param name="attemptNumber">The zero-based hedging attempt number.</param>
     /// <param name="callback">The callback passed to hedging strategy.</param>
     public HedgingActionGeneratorArguments(
@@ -33,12 +36,12 @@ public HedgingActionGeneratorArguments(
     }
 
     /// <summary>
-    /// Gets the primary resilience context.
+    /// Gets the primary resilience context as received by hedging strategy.
     /// </summary>
     public ResilienceContext PrimaryContext { get; }
 
     /// <summary>
-    /// Gets the context that will be passed to action generated by <see cref="HedgingStrategyOptions{TResult}.ActionGenerator"/>.
+    /// Gets the action context that will be used for the hedged action.
     /// </summary>
     /// <remarks>
     /// This context is cloned from <see cref="PrimaryContext"/>.

src/Polly.Core/Hedging/OnHedgingArguments.cs

@@ -14,9 +14,14 @@ public readonly struct OnHedgingArguments<TResult>
     /// <summary>
     /// Initializes a new instance of the <see cref="OnHedgingArguments{TResult}"/> struct.
     /// </summary>
-    /// <param name="primaryContext">The outcome of the resilience operation or event.</param>
-    /// <param name="actionContext">The action context.</param>
+    /// <param name="primaryContext">The primary context received by hedging strategy.</param>
+    /// <param name="actionContext">The action context. cloned from the primary context.</param>
     /// <param name="attemptNumber">The zero-based hedging attempt number.</param>
+    /// <remarks>
+    /// The <paramref name="primaryContext"/> represents the context that was received by the hedging strategy and used to execute the primary action.
+    /// To prevent race conditions, hedging strategy then clones the primary context into <paramref name="actionContext"/> and uses it to execute the hedged action.
+    /// Every hedged action gets its own context that is cloned from primary.
+    /// </remarks>
     public OnHedgingArguments(ResilienceContext primaryContext, ResilienceContext actionContext, int attemptNumber)
     {
         PrimaryContext = primaryContext;
@@ -25,7 +30,7 @@ public OnHedgingArguments(ResilienceContext primaryContext, ResilienceContext ac
     }
 
     /// <summary>
-    /// Gets the primary resilience context.
+    /// Gets the primary resilience context as received by hedging strategy.
     /// </summary>
     public ResilienceContext PrimaryContext { get; }