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stgsharp/StgSharp.Common/HighPerformance/Memory/L4.Slab.cs
T

103 lines
3.5 KiB
C#

//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="L4.Slab"
// Project: StgSharp
// AuthorGroup: Nitload
// Copyright (c) Nitload. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// -----------------------------------------------------------------------
// -----------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tlsf = StgSharp.HighPerformance.Memory.TwoLayerSegregatedFitAllocator;
namespace StgSharp.HighPerformance.Memory
{
public partial class L4
{
private sealed unsafe class Slab : SlabAllocator<Tlsf.Metadata>
{
private const int Capacity = L4.CacheLineCount;
private int _maxUnused;
private int _recycleCount;
internal readonly CacheLineHead* _basePtr;
internal readonly int* _indexReuse;
public Slab(
nuint ptr
)
{
_basePtr = (CacheLineHead*)ptr;
_indexReuse = (int*)(_basePtr + Capacity);
_maxUnused = 0;
_recycleCount = 0;
}
public static nuint RequestedAllocation { get; } = ((nuint)(Unsafe.SizeOf<CacheLineHead>() + sizeof(int))) * Capacity;
public override nuint Allocate()
{
if (_recycleCount > 0) {
return (nuint)(_basePtr + _indexReuse[_recycleCount - 1]);
}
if (_maxUnused >= Capacity) {
throw new OverflowException("Slab is full");
}
int index = _maxUnused;
_maxUnused++;
return (nuint)(_basePtr + index);
}
public override void Dispose()
{
GC.SuppressFinalize(this);
}
public override void EnterBufferReading() { }
public override void ExitBufferReading() { }
public override void Free(
nuint index
)
{
_indexReuse[_recycleCount] = (int)index;
_recycleCount++;
}
public override SlabAllocationHandle<Tlsf.Metadata> ReadAllocation()
{
return new(this, false);
}
}
}
}