Finalizer asserts unpinned memory only for one-time-use blocks / Pin() Asserts repinning of unpinned blocks / Unpin() Asserts definite Pinned memory / Capitalization

Author: clrjunkie

src/Microsoft.AspNet.Server.Kestrel/Infrastructure/MemoryPoolBlock2.cs

@@ -74,17 +74,22 @@ protected MemoryPoolBlock2()
         /// </summary>
         public MemoryPoolBlock2 Next { get; set; }
 
+        /// <summary>
+        /// Finalizes this instance.
+        /// </summary>
         ~MemoryPoolBlock2()
         {
-            Debug.Assert(!_pinHandle.IsAllocated, "Ad-hoc memory block wasn't unpinned");
-            // Debug.Assert(Slab == null || !Slab.IsActive, "Block being garbage collected instead of returned to pool");
-
-            if (_pinHandle.IsAllocated)
+            if(_pinHandle != null)
             {
-                // if this is a one-time-use block, ensure that the GCHandle does not leak
-                _pinHandle.Free();
-            }
+                Debug.Assert(!_pinHandle.IsAllocated, "One-time-use memory is unpinned");
 
+                if(_pinHandle.IsAllocated)
+                {
+                    // TODO: Must be logged somehow.
+                    _pinHandle.Free();
+                }                
+            }
+                                    
             if (Slab != null && Slab.IsActive)
             {
                 Pool.Return(new MemoryPoolBlock2
@@ -104,17 +109,23 @@ protected MemoryPoolBlock2()
         /// </summary>
         /// <returns></returns>
         public IntPtr Pin()
-        {
-            Debug.Assert(!_pinHandle.IsAllocated);
-
+        {            
             if (_dataArrayPtr != IntPtr.Zero)
             {
-                // this is a slab managed block - use the native address of the slab which is always locked
+                // This is a slab managed block - use the native address of the slab which is always locked.
                 return _dataArrayPtr;
             }
             else
             {
-                // this is one-time-use memory - lock the managed memory until Unpin is called
+                // This block uses one-time-use memory.
+
+                if (_pinHandle != null)
+                {
+                    // This block was pinned at least once.
+
+                    Debug.Assert(!_pinHandle.IsAllocated, "One-time-use memory is unpinned");                    
+                }
+                 
                 _pinHandle = GCHandle.Alloc(Data.Array, GCHandleType.Pinned);
                 return _pinHandle.AddrOfPinnedObject();
             }
@@ -124,8 +135,10 @@ public void Unpin()
         {
             if (_dataArrayPtr == IntPtr.Zero)
             {
-                // this is one-time-use memory - unlock the managed memory
-                Debug.Assert(_pinHandle.IsAllocated);
+                // This block uses one-time-use memory.
+
+                Debug.Assert(_pinHandle != null && _pinHandle.IsAllocated, "One-time-use memory is pinned");
+
                 _pinHandle.Free();
             }
         }
@@ -148,7 +161,7 @@ public static MemoryPoolBlock2 Create(
         }
 
         /// <summary>
-        /// called when the block is returned to the pool. mutable values are re-assigned to their guaranteed initialized state.
+        /// Called when the block is returned to the pool. mutable values are re-assigned to their guaranteed initialized state.
         /// </summary>
         public void Reset()
         {
@@ -167,7 +180,7 @@ public override string ToString()
         }
 
         /// <summary>
-        /// acquires a cursor pointing into this block at the Start of "active" byte information
+        /// Acquires a cursor pointing into this block at the Start of "active" byte information
         /// </summary>
         /// <returns></returns>
         public MemoryPoolIterator2 GetIterator()