netcore/System.Private.CoreLib/shared/System/Buffers/MemoryHandle.cs

   1 // Licensed to the .NET Foundation under one or more agreements.
   2 // The .NET Foundation licenses this file to you under the MIT license.
   3 // See the LICENSE file in the project root for more information.
   4
   5 using System.Runtime.InteropServices;
   6
   7 namespace System.Buffers
   8 {
   9     /// <summary>
  10     /// A handle for the memory.
  11     /// </summary>
  12     public unsafe struct MemoryHandle : IDisposable
  13     {
  14         private void* _pointer;
  15         private GCHandle _handle;
  16         private IPinnable? _pinnable;
  17
  18         /// <summary>
  19         /// Creates a new memory handle for the memory.
  20         /// </summary>
  21         /// <param name="pointer">pointer to memory</param>
  22         /// <param name="pinnable">reference to manually managed object, or default if there is no memory manager</param>
  23         /// <param name="handle">handle used to pin array buffers</param>
  24         [CLSCompliant(false)]
  25         public MemoryHandle(void* pointer, GCHandle handle = default, IPinnable? pinnable = default)
  26         {
  27             _pointer = pointer;
  28             _handle = handle;
  29             _pinnable = pinnable;
  30         }
  31
  32         /// <summary>
  33         /// Returns the pointer to memory, where the memory is assumed to be pinned and hence the address won't change.
  34         /// </summary>
  35         [CLSCompliant(false)]
  36         public void* Pointer => _pointer;
  37
  38         /// <summary>
  39         /// Frees the pinned handle and releases IPinnable.
  40         /// </summary>
  41         public void Dispose()
  42         {
  43             if (_handle.IsAllocated)
  44             {
  45                 _handle.Free();
  46             }
  47
  48             if (_pinnable != null)
  49             {
  50                 _pinnable.Unpin();
  51                 _pinnable = null;
  52             }
  53
  54             _pointer = null;
  55         }
  56     }
  57 }