.Net性能调优-ArrayPool详情

internal sealed class TlsOverPerCoreLockedStacksArrayPool<T> : ArrayPool<T>
{
    private static readonly TlsOverPerCoreLockedStacksArrayPool<T> s_shared = new TlsOverPerCoreLockedStacksArrayPool<T>();

    public static ArrayPool<T> Shared => s_shared;
}

private static void TimeMonitor()
{
    //随机生成3000个数组的长度值
    var sizes = new int[30000];
    Parallel.For(0, 10000, x => { sizes[x] = new Random().Next(1024 * 800, 1024 * 1024); });

    //缓冲池方式租用数组
    var gcAllocate0 = GC.GetTotalAllocatedBytes();
    var watch = new Stopwatch();
    Console.WriteLine("start");
    watch.Start();
    for (int i = 0; i < 10000; i++)
    {
        //CreateArrayByPool(ArrayPool<int>.Shared, 1024 * 1024,sizes[i], false);

        var arr = ArrayPool<int>.Shared.Rent(sizes[i]);
        for (int j = 0; j < sizes[i]; j++)
        {
            arr[j] = i;
        }
        ArrayPool<int>.Shared.Return(arr, true);
    }
    var time1 = watch.ElapsedMilliseconds;
    var gcAllocate1 = GC.GetTotalAllocatedBytes(true);

    //new 方式分配数组空间
    watch.Restart();
    for (int i = 0; i < 30000; i++)
    {
        //CreateArrayDefault(i, sizes[i], false);
        var arr = new int[sizes[i]];
        for (int j = 0; j < sizes[i]; j++)
        {
            arr[j] = i;
        }
    }
    var time2 = watch.ElapsedMilliseconds;
    var gcAllocate2 = GC.GetTotalAllocatedBytes(true);

    Console.WriteLine("ArrayPool方式创建数组耗时：" + time1 + "  Gc总分配量" + (gcAllocate1 - gcAllocate0));
    Console.WriteLine("默认方式创建数组耗时：" + time2 + "  Gc总分配量" + (gcAllocate2 - gcAllocate1 - gcAllocate0));
}

private static void PostFileByBytesPool(FORMFile file)
{
    HttpClient client = new HttpClient() { BaseAddress = new Uri("https://fileserver.com") };

    var fileLen = (int)file.Length;
    var fileArr = ArrayPool<byte>.Shared.Rent(fileLen);

    using var stream = file.OpenReadStream();
    stream.Read(fileArr, 0, fileLen);

    MultipartFormDataContent content = new MultipartFormDataContent();
    content.Add(new ByteArrayContent(fileArr, 0, fileLen), "id_" + Guid.NewGuid().ToString(), file.FileName);

    client.PostAsync("/myfile/" + file.FileName, content).Wait();
    ArrayPool<byte>.Shared.Return(fileArr, true);
}

//创建一个自定义缓冲池实例，单个数组最大长度为1024 * 2048，最大可同时租用10个缓冲区
ArrayPool<int> CustomerArrayPool = ArrayPool<int>.Create(1024 * 2048,10);