133 lines
6.3 KiB
C#
133 lines
6.3 KiB
C#
//-----------------------------------------------------------------------
|
|
// -----------------------------------------------------------------------
|
|
// file="SlabAllocator.cs"
|
|
// Project: StgSharp
|
|
// AuthorGroup: Nitload Space
|
|
// Copyright (c) Nitload Space. 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 StgSharp.HighPerformance.Memory;
|
|
using System;
|
|
|
|
namespace StgSharp.Mathematics.Memory
|
|
{
|
|
public static class SlabAllocator
|
|
{
|
|
|
|
/// <summary>
|
|
/// Creates a new SLAB allocator instance with the specified configuration.
|
|
/// </summary>
|
|
/// <param name="count">
|
|
/// Initial number of objects that can be allocated.
|
|
/// </param>
|
|
/// <param name="layout">
|
|
/// Memory layout strategy for the SLAB allocator.
|
|
/// </param>
|
|
/// <param name="concurrentSupport">
|
|
/// Whether to enable concurrent access support.
|
|
/// </param>
|
|
/// <returns>
|
|
/// A new SLAB allocator instance.
|
|
/// </returns>
|
|
/// <exception cref="ArgumentOutOfRangeException">
|
|
/// Thrown when an invalid layout is specified.
|
|
/// </exception>
|
|
/// <exception cref="NotSupportedException">
|
|
/// Thrown when requesting unsupported configurations.
|
|
/// </exception>
|
|
/// <remarks>
|
|
/// <para><strong> Important Threading Considerations: </strong></para> <para>While SLAB
|
|
/// /// /// allocators themselves may be designed for single-threaded use, allocated
|
|
/// objects /// are /// frequently shared across multiple threads in real-world
|
|
/// applications. Due to /// the /// special implementation of expandable concurrent
|
|
/// sequential SLAB allocators, /// they rely /// on internal expansion locks to
|
|
/// ensure that memory buffer expansions /// (which involve /// copying the entire
|
|
/// buffer to a new location) do not occur while /// other threads are /// reading
|
|
/// from allocated regions. </para> <para><strong>/// Sequential Layout Limitations:
|
|
/// ///</strong><br /> Sequential layout SLAB allocators /// cannot provide a single-
|
|
/// threaded /// version because:<list /// type="bullet"><item><description>They use
|
|
/// contiguous memory /// layout that requires /// buffer expansion when capacity is
|
|
/// exceeded /// ///</description></item><item><description>Buffer expansion involves
|
|
/// copying all /// /// existing data to a new memory
|
|
/// location</description></item><item><description> /// /// Without proper
|
|
/// synchronization, concurrent access to allocated objects during /// /// expansion
|
|
/// would cause memory corruption</description></item><item><description>The /// ///
|
|
/// expansion lock mechanism is essential even if allocation itself is single- /// ///
|
|
/// threaded </description></item></list></para> <para><strong>Chunked Layout: ///
|
|
/// ///</strong><br /> Chunked layout allocators can optionally provide single-threaded
|
|
/// /// /// versions since they don't require buffer expansion and copying. Each
|
|
/// chunk is /// /// allocated independently, avoiding the memory relocation issues
|
|
/// present in /// sequential /// layouts. </para>
|
|
/// </remarks>
|
|
public static SlabAllocator<T> Create<T>(nuint count, SlabBufferLayout layout, bool concurrentSupport = true)
|
|
where T: unmanaged
|
|
{
|
|
return layout switch
|
|
{
|
|
SlabBufferLayout.Sequential => concurrentSupport ?
|
|
new ConcurrentSequentialSlabAllocator<T>(count) :
|
|
throw new NotSupportedException("Non-concurrent version of sequential layout SLAB is not supported due to expansion lock requirements for memory safety during buffer expansion."),
|
|
SlabBufferLayout.Chunked => concurrentSupport ?
|
|
new ConcurrentChunkedSlabAllocator<T>(count) :
|
|
new ChunkedSlabAllocator<T>(count),
|
|
_ => throw new ArgumentOutOfRangeException(nameof(layout), layout, null)
|
|
};
|
|
}
|
|
|
|
[MethodImpl(MethodImplOptions.AggressiveInlining)]
|
|
public static SlabAllocator<T> FromBuffer<T>(nuint buffer, nuint count, Action<nuint> freeHandle)
|
|
where T: unmanaged
|
|
{
|
|
return new FixedSlabAllocator<T>(buffer, count, freeHandle);
|
|
}
|
|
|
|
}
|
|
|
|
public abstract class SlabAllocator<T> : IDisposable where T: unmanaged
|
|
{
|
|
|
|
public abstract nuint Allocate();
|
|
|
|
public abstract void Dispose();
|
|
|
|
public abstract void EnterBufferReading();
|
|
|
|
public abstract void ExitBufferReading();
|
|
|
|
public abstract void Free(nuint index);
|
|
|
|
public abstract SlabAllocationHandle<T> ReadAllocation();
|
|
|
|
}
|
|
|
|
public enum SlabBufferLayout
|
|
{
|
|
|
|
Sequential,
|
|
Chunked
|
|
|
|
}
|
|
}
|