Memory Changes part 2 (ryubing/ryujinx!123)

See merge request ryubing/ryujinx!123

src/Ryujinx.Common/Memory/MemoryOwner.cs

@@ -1,6 +1,7 @@
 #nullable enable
 using System;
 using System.Buffers;
+using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
@@ -10,11 +11,126 @@ namespace Ryujinx.Common.Memory
 {
     /// <summary>
     /// An <see cref="IMemoryOwner{T}"/> implementation with an embedded length and fast <see cref="Span{T}"/>
-    /// accessor, with memory allocated from <seealso cref="ArrayPool{T}.Shared"/>.
+    /// accessor, with memory allocated from <see cref="ArrayPooling"/>.
     /// </summary>
     /// <typeparam name="T">The type of item to store.</typeparam>
     public sealed class MemoryOwner<T> : IMemoryOwner<T>
     {
+        private static class ArrayPooling
+        {
+            public class Holder(T[]? array = null) : IComparable<Holder>, IComparable<int>
+            {
+                public int SkipCount;
+                public readonly T[]? Array = array;
+
+                public int CompareTo(Holder? other)
+                {
+                    return Array!.Length.CompareTo(other!.Array!.Length);
+                }
+                
+                public int CompareTo(int other)
+                {
+                    int self = Array!.Length;
+
+                    if (self < other)
+                    {
+                        SkipCount++;
+                        return -1;
+                    }
+
+                    if (self > other * 4)
+                    {
+                        return 1;
+                    }
+                    
+                    return 0;
+                }
+            }
+            
+            // ReSharper disable once StaticMemberInGenericType
+            private static int _maxCacheCount = 50;
+            
+            private const int MaxSkipCount = 50;
+        
+            static readonly List<Holder> _pool = new();
+            
+            // ReSharper disable once StaticMemberInGenericType
+            static readonly Lock _lock = new();
+            
+            private static int BinarySearch(List<Holder> list, int size)
+            {
+                int min = 0;
+                int max = list.Count-1;
+
+                while (min <= max)
+                {
+                    int mid = (min + max) / 2;
+                    int comparison = list[mid].CompareTo(size);
+                    if (comparison == 0)
+                    {
+                        return mid;
+                    }
+                    if (comparison < 0)
+                    {
+                        min = mid+1;
+                    }
+                    else
+                    {
+                        max = mid-1;
+                    }
+                }
+                return ~min;
+            }
+
+            public static T[] Get(int minimumSize)
+            {
+                lock (_lock)
+                {
+                    int index = BinarySearch(_pool, minimumSize);
+
+                    if (index >= 0)
+                    {
+                        Holder holder = _pool[index];
+                        
+                        _pool.Remove(holder);
+                        return holder.Array!;
+                    }
+
+                    return new T[minimumSize];
+                }
+            }
+
+            public static void Return(T[] array)
+            {
+
+                lock (_lock)
+                {
+                    Holder holder = new(array);
+                    int i = _pool.BinarySearch(holder);
+                    if (i < 0)
+                    {
+                        _pool.Insert(~i, holder);
+                    }
+
+                    if (_pool.Count >= _maxCacheCount)
+                    {
+                        for (int index = 0; index < _pool.Count; index++)
+                        {
+                            Holder h = _pool[index];
+
+                            if (h.SkipCount >= MaxSkipCount)
+                            {
+                                _pool.Remove(h);
+                                index--;
+                            }
+                        }
+                        
+                        _maxCacheCount = _pool.Count * 2;
+                    }
+                }
+            }
+        }
+        
         private readonly int _length;
         private T[]? _array;
 
@@ -25,7 +141,7 @@ namespace Ryujinx.Common.Memory
         private MemoryOwner(int length)
         {
             _length = length;
-            _array = ArrayPool<T>.Shared.Rent(length);
+            _array = ArrayPooling.Get(length);
         }
 
         /// <summary>
@@ -124,7 +240,7 @@ namespace Ryujinx.Common.Memory
 
             if (array is not null)
             {
-                ArrayPool<T>.Shared.Return(array, RuntimeHelpers.IsReferenceOrContainsReferences<T>());
+                ArrayPooling.Return(array);
             }
         }