diff --git a/src/IKVM.ByteCode/Buffers/MappedFileMemoryManager.cs b/src/IKVM.ByteCode/Buffers/MappedFileMemoryManager.cs
index 20627e9..aa1973e 100644
--- a/src/IKVM.ByteCode/Buffers/MappedFileMemoryManager.cs
+++ b/src/IKVM.ByteCode/Buffers/MappedFileMemoryManager.cs
@@ -15,6 +15,7 @@ sealed unsafe class MappedFileMemoryManager : MemoryManager<byte>
 
         readonly MemoryMappedFile _file;
         readonly MemoryMappedViewAccessor _view;
+        readonly byte* _addr;
 
         /// <summary>
         /// Initializes a new instance.
@@ -31,15 +32,15 @@ public MappedFileMemoryManager(MemoryMappedFile file, MemoryMappedViewAccessor v
                 throw new InvalidOperationException();
             if (_view.SafeMemoryMappedViewHandle.IsClosed || _view.SafeMemoryMappedViewHandle.IsInvalid)
                 throw new InvalidOperationException();
+
+            _view.SafeMemoryMappedViewHandle.AcquirePointer(ref _addr);
         }
 
         /// <inheritdoc />
         public override Span<byte> GetSpan()
         {
-            byte* ptr = null;
-            _view.SafeMemoryMappedViewHandle.AcquirePointer(ref ptr);
             var len = _view.SafeMemoryMappedViewHandle.ByteLength;
-            return new Span<byte>(ptr, checked((int)len));
+            return new Span<byte>(_addr, checked((int)len));
         }
 
         /// <inheritdoc />
@@ -48,9 +49,7 @@ public override MemoryHandle Pin(int elementIndex = 0)
             if (elementIndex < 0 || elementIndex >= checked((int)_view.SafeMemoryMappedViewHandle.ByteLength))
                 throw new ArgumentOutOfRangeException(nameof(elementIndex));
 
-            byte* ptr = null;
-            _view.SafeMemoryMappedViewHandle.AcquirePointer(ref ptr);
-            return new MemoryHandle(Unsafe.Add<byte>(ptr, elementIndex));
+            return new MemoryHandle(Unsafe.Add<byte>(_addr, elementIndex));
         }
 
         /// <inheritdoc />
@@ -62,11 +61,9 @@ public override void Unpin()
         /// <inheritdoc />
         protected override void Dispose(bool disposing)
         {
-            if (true)
-            {
-                _view.Dispose();
-                _file.Dispose();
-            }
+            _view.SafeMemoryMappedViewHandle.ReleasePointer();
+            _view.Dispose();
+            _file.Dispose();
         }
 
     }
diff --git a/src/IKVM.ByteCode/Decoding/ClassFile.cs b/src/IKVM.ByteCode/Decoding/ClassFile.cs
index cc3919a..be39ced 100644
--- a/src/IKVM.ByteCode/Decoding/ClassFile.cs
+++ b/src/IKVM.ByteCode/Decoding/ClassFile.cs
@@ -19,7 +19,6 @@ public sealed class ClassFile : IDisposable
         public const uint MAGIC = 0xCAFEBABE;
         public const uint MIN_CLASS_SIZE = 30;
 
-
         /// <summary>
         /// Attempts to measure a class starting at the current position.
         /// </summary>
@@ -178,20 +177,19 @@ public static bool TryRead(in ReadOnlySequence<byte> buffer, out ClassFile? claz
         /// <exception cref="ByteCodeException"></exception>
         public static bool TryMeasure(in ReadOnlySequence<byte> buffer, ref int size, out SequencePosition consumed, out SequencePosition examined)
         {
-            consumed = buffer.Start;
-
             var reader = new ClassFormatReader(buffer);
             if (TryMeasure(ref reader, ref size) == false)
             {
-                // examined up to the position of the reader, but consumed nothing
-                examined = reader.Position;
+                // examined up to the end of the buffer, but consumed nothing
+                examined = buffer.End;
+                consumed = buffer.Start;
                 return false;
             }
             else
             {
-                // examined up to the point of the reader, consumed the same
+                // examined up to the end of thebuffer, but consumed up until the position of the reader
+                examined = buffer.End;
                 consumed = reader.Position;
-                examined = reader.Position;
                 return true;
             }
         }
diff --git a/src/IKVM.ByteCode/Text/EncodingExtensions.cs b/src/IKVM.ByteCode/Text/EncodingExtensions.cs
index 83d801a..1c925c1 100644
--- a/src/IKVM.ByteCode/Text/EncodingExtensions.cs
+++ b/src/IKVM.ByteCode/Text/EncodingExtensions.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Text;
 
 namespace IKVM.ByteCode.Text
 {