Fix an assert in PoolingAsyncValueTaskMethodBuilder (#56468)

dotnet · Jul 28, 2021 · f5a7304 · f5a7304
1 parent fe4d5cf
commit f5a7304
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Showing 2 changed files with 13 additions and 9 deletions.
diff --git a/...rivate.CoreLib/src/System/Runtime/CompilerServices/PoolingAsyncValueTaskMethodBuilderT.cs b/...rivate.CoreLib/src/System/Runtime/CompilerServices/PoolingAsyncValueTaskMethodBuilderT.cs
@@ -356,14 +356,18 @@ private void ReturnToCache()
                     // Get the current processor ID.  We need to ensure it fits within s_perCoreCache, so we
                     // could % by its length, but we can do so instead by Environment.ProcessorCount, which will be a const
                     // in tier 1, allowing better code gen, and then further use uints for even better code gen.
-                    Debug.Assert(s_perCoreCache.Length == Environment.ProcessorCount);
+                    Debug.Assert(s_perCoreCache.Length == Environment.ProcessorCount, $"{s_perCoreCache.Length} != {Environment.ProcessorCount}");
                     int i = (int)((uint)Thread.GetCurrentProcessorId() % (uint)Environment.ProcessorCount);
 
                     // We want an array of StateMachineBox<> objects, each consuming its own cache line so that
                     // elements don't cause false sharing with each other.  But we can't use StructLayout.Explicit
                     // with generics.  So we use object fields, but always reinterpret them (for all reads and writes
                     // to avoid any safety issues) as StateMachineBox<> instances.
-                    Debug.Assert(s_perCoreCache[i].Object is null || s_perCoreCache[i].Object is StateMachineBox<TStateMachine>);
+#if DEBUG
+                    object? transientValue = s_perCoreCache[i].Object;
+                    Debug.Assert(transientValue is null || transientValue is StateMachineBox<TStateMachine>,
+                        $"Expected null or {nameof(StateMachineBox<TStateMachine>)}, got '{transientValue}'");
+#endif
                     return ref Unsafe.As<object?, StateMachineBox<TStateMachine>?>(ref s_perCoreCache[i].Object);
                 }
             }
@@ -385,7 +389,7 @@ public void ClearStateUponCompletion()
             private static void ExecutionContextCallback(object? s)
             {
                 // Only used privately to pass directly to EC.Run
-                Debug.Assert(s is StateMachineBox<TStateMachine>);
+                Debug.Assert(s is StateMachineBox<TStateMachine>, $"Expected {nameof(StateMachineBox<TStateMachine>)}, got '{s}'");
                 Unsafe.As<StateMachineBox<TStateMachine>>(s).StateMachine!.MoveNext();
             }
 
@@ -402,7 +406,7 @@ public void MoveNext()
 
                 if (context is null)
                 {
-                    Debug.Assert(StateMachine is not null);
+                    Debug.Assert(StateMachine is not null, $"Null {nameof(StateMachine)}");
                     StateMachine.MoveNext();
                 }
                 else

diff --git a/...stem.Private.CoreLib/src/System/Threading/Tasks/Sources/ManualResetValueTaskSourceCore.cs b/...stem.Private.CoreLib/src/System/Threading/Tasks/Sources/ManualResetValueTaskSourceCore.cs
@@ -107,7 +107,7 @@ private void ThrowForFailedGetResult(short token)
             }
 
             _error?.Throw();
-            Debug.Fail("Should not get here");
+            Debug.Fail($"{nameof(ThrowForFailedGetResult)} should never get here");
         }
 
         /// <summary>Schedules the continuation action for this operation.</summary>
@@ -250,8 +250,8 @@ private void InvokeContinuationWithContext()
             // for the surrounding code to become less efficent (stack spills etc)
             // and it is an uncommon path.
 
-            Debug.Assert(_continuation != null);
-            Debug.Assert(_executionContext != null);
+            Debug.Assert(_continuation != null, $"Null {nameof(_continuation)}");
+            Debug.Assert(_executionContext != null, $"Null {nameof(_executionContext)}");
 
             ExecutionContext? currentContext = ExecutionContext.CaptureForRestore();
             // Restore the captured ExecutionContext before executing anything.
@@ -321,8 +321,8 @@ private void InvokeContinuationWithContext()
         /// </summary>
         private void InvokeSchedulerContinuation()
         {
-            Debug.Assert(_capturedContext != null);
-            Debug.Assert(_continuation != null);
+            Debug.Assert(_capturedContext != null, $"Null {nameof(_capturedContext)}");
+            Debug.Assert(_continuation != null, $"Null {nameof(_continuation)}");
 
             switch (_capturedContext)
             {