Update xml comment for {ReadOnly}Memory.Pin method (dotnet/corefx#29137) (#17709)

Signed-off-by: dotnet-bot-corefx-mirror <dotnet-bot@microsoft.com>

diff --git a/src/mscorlib/shared/System/Memory.cs b/src/mscorlib/shared/System/Memory.cs
index 98ec23f..c06b1b4 100644 (file)
--- a/src/mscorlib/shared/System/Memory.cs
+++ b/src/mscorlib/shared/System/Memory.cs
@@ -348,13 +348,26 @@ namespace System
             }
             else if (_object is T[] array)
             {
-                GCHandle handle = _length < 0 ? default : GCHandle.Alloc(array, GCHandleType.Pinned);
+                // Array is already pre-pinned
+                if (_length < 0)
+                {
 #if FEATURE_PORTABLE_SPAN
-                void* pointer = Unsafe.Add<T>((void*)handle.AddrOfPinnedObject(), _index);
+                    void* pointer = Unsafe.Add<T>(Unsafe.AsPointer(ref MemoryMarshal.GetReference<T>(array)), _index);
 #else
-                void* pointer = Unsafe.Add<T>(Unsafe.AsPointer(ref array.GetRawSzArrayData()), _index);
+                    void* pointer = Unsafe.Add<T>(Unsafe.AsPointer(ref array.GetRawSzArrayData()), _index);
 #endif // FEATURE_PORTABLE_SPAN
-                return new MemoryHandle(pointer, handle);
+                    return new MemoryHandle(pointer);
+                }
+                else
+                {
+                    GCHandle handle = GCHandle.Alloc(array, GCHandleType.Pinned);
+#if FEATURE_PORTABLE_SPAN
+                    void* pointer = Unsafe.Add<T>((void*)handle.AddrOfPinnedObject(), _index);
+#else
+                    void* pointer = Unsafe.Add<T>(Unsafe.AsPointer(ref array.GetRawSzArrayData()), _index);
+#endif // FEATURE_PORTABLE_SPAN
+                    return new MemoryHandle(pointer, handle);
+                }
             }
             return default;
         }

diff --git a/src/mscorlib/shared/System/ReadOnlyMemory.cs b/src/mscorlib/shared/System/ReadOnlyMemory.cs
index ae8a7c3..91a3522 100644 (file)
--- a/src/mscorlib/shared/System/ReadOnlyMemory.cs
+++ b/src/mscorlib/shared/System/ReadOnlyMemory.cs
@@ -260,13 +260,26 @@ namespace System
             }
             else if (_object is T[] array)
             {
-                GCHandle handle = _length < 0 ? default : GCHandle.Alloc(array, GCHandleType.Pinned);
+                // Array is already pre-pinned
+                if (_length < 0)
+                {
 #if FEATURE_PORTABLE_SPAN
-                void* pointer = Unsafe.Add<T>((void*)handle.AddrOfPinnedObject(), _index);
+                    void* pointer = Unsafe.Add<T>(Unsafe.AsPointer(ref MemoryMarshal.GetReference<T>(array)), _index);
 #else
-                void* pointer = Unsafe.Add<T>(Unsafe.AsPointer(ref array.GetRawSzArrayData()), _index);
+                    void* pointer = Unsafe.Add<T>(Unsafe.AsPointer(ref array.GetRawSzArrayData()), _index);
 #endif // FEATURE_PORTABLE_SPAN
-                return new MemoryHandle(pointer, handle);
+                    return new MemoryHandle(pointer);
+                }
+                else
+                {
+                    GCHandle handle = GCHandle.Alloc(array, GCHandleType.Pinned);
+#if FEATURE_PORTABLE_SPAN
+                    void* pointer = Unsafe.Add<T>((void*)handle.AddrOfPinnedObject(), _index);
+#else
+                    void* pointer = Unsafe.Add<T>(Unsafe.AsPointer(ref array.GetRawSzArrayData()), _index);
+#endif // FEATURE_PORTABLE_SPAN
+                    return new MemoryHandle(pointer, handle);
+                }
             }
             return default;
         }