// -----------------------------------------------------------------------------
// file="SlabStressTest"
// Project: StgSharp
// Copyright (c) Nitload.
// SPDX-License-Identifier: MIT
// -----------------------------------------------------------------------------

using StgSharp.HighPerformance.Memory;
using System;
using System.Diagnostics;

namespace StgSharp
{
    internal static class SlabStressTest
    {

        // Exercise the Nonconcurrent Chunked SLAB used by HLSF (allocation/free only)
        public static unsafe void Run()
        {
            Console.WriteLine("=== SLAB Allocator (Chunked) Single-Thread Stress Test ===");

            // Use SLAB with element size of pointer (nuint) to simulate Entry handles
            SlabAllocator<BunchOfBytes> slab = SlabAllocator.Create<BunchOfBytes>(64, SlabBufferLayout.Chunked, false);

            int cycles = 10;
            int allocsPerCycle = 200_000; // large enough to force internal growth

            Stopwatch sw = new Stopwatch();

            for (int c = 0; c < cycles; c++)
            {
                Console.WriteLine($"--- Cycle {c+1} ---");
                nuint[] ptrs = new nuint[allocsPerCycle];

                sw.Restart();
                for (int i = 0; i < allocsPerCycle; i++) {
                    ptrs[i] = slab.Allocate();
                }
                sw.Stop();
                Console.WriteLine($"Allocate: {allocsPerCycle} in {sw.Elapsed.TotalSeconds:0.00}s");

                sw.Restart();
                for (int i = 0; i < allocsPerCycle; i++) {
                    slab.Free(ptrs[i]);
                }
                sw.Stop();
                Console.WriteLine($"Free: {allocsPerCycle} in {sw.Elapsed.TotalSeconds:0.00}s");
            }

            slab.Dispose();
            Console.WriteLine("=== SLAB Stress Complete ===");
        }

        internal unsafe struct BunchOfBytes
        {

            public fixed byte Data[128];

        }

    }
}