140 lines
4.7 KiB
C#
140 lines
4.7 KiB
C#
using OpenCvSharp;
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namespace SHH.CameraSdk;
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/// <summary>
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/// [零延迟核心] 智能帧对象池
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/// 功能：预分配并复用 SmartFrame 实例，杜绝频繁 new Mat() 与 GC 回收，消除内存分配停顿
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/// 核心策略：
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/// <para>1. 预热分配：启动时创建初始数量帧，避免运行时内存申请</para>
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/// <para>2. 上限控制：最大池大小限制内存占用，防止内存溢出</para>
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/// <para>3. 背压丢帧：池空时返回 null，强制丢帧保证实时性，不阻塞生产端</para>
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/// </summary>
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public class FramePool : IDisposable
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{
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#region --- 私有资源与配置 (Private Resources & Configurations) ---
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/// <summary> 可用帧队列（线程安全）：存储待借出的空闲智能帧 </summary>
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private readonly ConcurrentQueue<SmartFrame> _availableFrames = new();
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/// <summary> 所有已分配帧列表：用于统一销毁释放内存 </summary>
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private readonly List<SmartFrame> _allAllocatedFrames = new();
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/// <summary> 创建新帧锁：确保多线程下创建新帧的线程安全 </summary>
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private readonly object _lock = new();
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/// <summary> 帧宽度（与相机输出分辨率一致） </summary>
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private readonly int _width;
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/// <summary> 帧高度（与相机输出分辨率一致） </summary>
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private readonly int _height;
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/// <summary> 帧数据类型（如 CV_8UC3 对应 RGB 彩色图像） </summary>
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private readonly MatType _type;
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/// <summary> 池最大容量：限制最大分配帧数，防止内存占用过高 </summary>
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private readonly int _maxPoolSize;
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#endregion
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#region --- 构造与预热 (Constructor & Warm-Up) ---
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/// <summary>
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/// 初始化智能帧对象池
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/// </summary>
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/// <param name="width">帧宽度</param>
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/// <param name="height">帧高度</param>
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/// <param name="type">帧数据类型</param>
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/// <param name="initialSize">初始预热帧数（默认5）</param>
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/// <param name="maxSize">池最大容量（默认10）</param>
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public FramePool(int width, int height, MatType type, int initialSize = 5, int maxSize = 10)
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{
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_width = width;
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_height = height;
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_type = type;
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_maxPoolSize = maxSize;
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// 预热：启动时预分配初始数量帧，避免运行时动态申请内存
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for (int i = 0; i < initialSize; i++)
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{
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CreateNewFrame();
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}
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}
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/// <summary>
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/// 创建新智能帧并加入池（内部调用，加锁保护）
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/// </summary>
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private void CreateNewFrame()
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{
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var frame = new SmartFrame(this, _width, _height, _type);
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_allAllocatedFrames.Add(frame);
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_availableFrames.Enqueue(frame);
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}
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#endregion
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#region --- 帧借出与归还 (Frame Borrow & Return) ---
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/// <summary>
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/// 从池借出一个智能帧（O(1) 时间复杂度）
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/// </summary>
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/// <returns>可用智能帧 / 池空且达上限时返回 null（触发背压丢帧）</returns>
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public SmartFrame Get()
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{
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// 1. 优先从可用队列取帧，无锁快速路径
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if (_availableFrames.TryDequeue(out var frame))
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{
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frame.Activate();
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return frame;
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}
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// 2. 可用队列为空，检查是否达最大容量
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if (_allAllocatedFrames.Count < _maxPoolSize)
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{
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// 加锁创建新帧，避免多线程重复创建
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lock (_lock)
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{
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// 双重检查：防止等待锁期间其他线程已创建新帧
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if (_allAllocatedFrames.Count < _maxPoolSize)
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{
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CreateNewFrame();
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}
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}
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// 递归重试取帧
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return Get();
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}
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// 3. 背压策略：池空且达上限，返回 null 强制丢帧，保证生产端不阻塞
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// 适用场景：消费端处理过慢导致帧堆积，丢帧保实时性
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return null;
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}
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/// <summary>
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/// [系统内部调用] 将帧归还至池（由 SmartFrame.Dispose 自动触发）
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/// </summary>
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/// <param name="frame">待归还的智能帧</param>
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public void Return(SmartFrame frame)
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{
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_availableFrames.Enqueue(frame);
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}
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#endregion
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#region --- 资源释放 (Resource Disposal) ---
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/// <summary>
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/// 释放帧池所有资源，销毁所有 Mat 内存
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/// </summary>
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public void Dispose()
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{
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// 遍历所有已分配帧，释放 OpenCV Mat 底层内存
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foreach (var frame in _allAllocatedFrames)
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{
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frame.InternalMat.Dispose();
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}
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_allAllocatedFrames.Clear();
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_availableFrames.Clear();
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}
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#endregion
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} |