LayerBase.Task 1.4.9

🚀 LayerBase.Task: 工业级游戏异步任务系统

LayerBase.Task 是 LayerBase 架构总线的核心基建之一，提供了一套专为游戏引擎（如 Unity、Godot）心跳循环（Pump）深度调优的零分配（Zero-Allocation）异步任务模型：LBTask。

🎯 为什么要开发 LBTask？

在现代游戏开发中，异步操作（如等待动画播放、网络请求回调、分帧加载）无处不在。使用 C# 标准的 Task 或 Task<T> 会面临一个无法回避的痛点： 每次 await Task 都会在托管堆上分配内存。 在一秒钟 60 帧或 120 帧的游戏主循环中，这种高频的堆分配会导致严重的垃圾回收（GC）尖峰，从而引发游戏卡顿和掉帧。

LBTask 专为此而生：

1. 同步路径零 GC 分配：通过内置的池化技术与状态机机机制，如果一个异步任务是同步完成的，它将绝对不会在堆上产生任何 GC Allocation。
2. 双核驱动机制 (自驱动延迟 + 帧同步)：
   • 自驱动的 Delay：LBTask.Delay 底层自带了一个基于最小堆（Min-Heap）和 System.Threading.Timer 的高精度调度器。它完全是自驱动的，跑在线程池中，不需要依赖主循环的 Pump 来推进时间，这意味着即便主线程卡死，您的异步超时逻辑依然精准。
   • 帧同步与线程回归：对于 NextFrame() 或回到主线程的操作，LBTask 依赖标准的 SynchronizationContext。如果您在 Unity 中，它会自动使用 Unity 的上下文；如果您在纯 C# 服务端，可以手动调用 LayerBaseSynchronizationContext.InstallAsCurrent() 并在您的主循环中驱动它。
3. 极简 API：保留了原生 Task 的手感，支持 await LBTask.Delay()、await LBTask.NextFrame() 等特性。

📦 如何单独使用？

虽然本包默认已随主库 LayerBase 自动集成，但您完全可以将它剥离出来单独使用，作为原生 Task 的零 GC 替代品。

1. 基础的异步延迟 (自驱动)

LBTask.Delay 不需要任何外部驱动，直接 await 即可享受 0 GC 的延迟：

public async LBTask DoSomethingDelay()
{
    // 底层由内置的 DelayScheduler 处理，不产生 Task 堆分配
    await LBTask.Delay(TimeSpan.FromSeconds(3f));
    Console.WriteLine("3 秒后触发...");
}

2. 帧同步与上下文配置 (如需独立驱动)

如果您想使用 LBTask.NextFrame()，或者希望确保 await 之后的代码回到您的主线程，您需要一个同步上下文。

• 在 Unity / Godot 中：引擎已经为您配置好了原生的上下文，直接使用即可。
• 在纯 C# 环境中：您可以使用内置的 LayerBaseSynchronizationContext：

// 1. 在游戏/服务器启动时，安装上下文
var ctx = LayerBaseSynchronizationContext.InstallAsCurrent();

// 2. 编写分帧逻辑
public async LBTask FrameLogic()
{
    Console.WriteLine("第一帧");
    await LBTask.NextFrame();
    Console.WriteLine("第二帧 (已回到主线程)");
}

// 3. 在您的主循环 (如 while (true) 或者是 Update) 中驱动它
public void GameLoop()
{
    // 调用 Update 消费 NextFrame 与 Post 进来的回调
    ctx.Update(); 
}

返回值的异步任务 (LBTask<T>)

除了空任务，LBTask 也支持携带泛型返回值，其底层使用了 LBTaskCompletionSource<T> 实现了零分配的缓存回收：

public async LBTask<int> CalculateHeavyDataAsync()
{
    await LBTask.Delay(TimeSpan.FromSeconds(1));
    return 42;
}

public async LBTask RunTest()
{
    int result = await CalculateHeavyDataAsync();
    Console.WriteLine(result);
}

⚙️ 核心 API 总览

• LBTask.CompletedTask: 返回一个已完成的 LBTask（零分配）。
• LBTask.Delay(TimeSpan): 提供基于引擎时间的延迟操作。
• LBTask.Delay(int milliseconds): 基于毫秒的延迟。
• LBTask.NextFrame(): 等待至引擎驱动的下一帧。
• LBTaskCompletionSource<T>: 手动控制生命周期的异步状态源，推荐用于包装外部的跨线程回调。

🔗 关于 LayerBase

LayerBase.Task 是 LayerBase 高性能架构生态的一环，配合底层总线（1.5亿 TPS 分发）和源生成器（零反射依赖注入）使用，可解锁完整的工业级能力。

项目主页：LayerBase GitHub 仓库

🚀 LayerBase.Task: Industrial-Grade Game Async Task System

LayerBase.Task is one of the core infrastructure components of the LayerBase Architecture Bus. It provides LBTask, a Zero-Allocation asynchronous task model deeply optimized for game engine (e.g., Unity, Godot) heartbeat loops (Pump).

🎯 Why Develop LBTask?

In modern game development, asynchronous operations (such as waiting for animations, network request callbacks, and frame-split loading) are everywhere. Using standard C# Task or Task<T> faces an unavoidable pain point: Every await Task allocates memory on the managed heap. In a game main loop running at 60 or 120 FPS, these high-frequency heap allocations lead to severe Garbage Collection (GC) spikes, causing stutters and frame drops.

LBTask was born to solve this:

1. Zero GC Allocation on Synchronous Paths: Through built-in pooling and state machine mechanisms, if an async task completes synchronously, it will absolutely not produce any GC Allocation on the heap.
2. Dual-Core Drive Mechanism (Self-Driven Delay + Frame Sync):
   • Self-Driven Delay: LBTask.Delay features an underlying high-precision scheduler based on a Min-Heap and System.Threading.Timer. It is entirely self-driven, running on the ThreadPool, and does not rely on the main loop's Pump to advance time. This means even if the main thread hangs, your async timeout logic remains precise.
   • Frame Sync & Thread Regression: For NextFrame() or operations returning to the main thread, LBTask relies on the standard SynchronizationContext. In Unity, it automatically uses Unity's context; in pure C# servers, you can manually call LayerBaseSynchronizationContext.InstallAsCurrent() and drive it within your main loop.
3. Minimal API: Maintains the "feel" of native Tasks, supporting features like await LBTask.Delay(), await LBTask.NextFrame(), etc.

📦 How to Use Standalone?

While this package is integrated by default with the main LayerBase library, you can strip it out and use it independently as a Zero-GC replacement for native Task.

1. Basic Async Delay (Self-Driven)

LBTask.Delay requires no external driver; simply await it to enjoy 0-GC delays:

public async LBTask DoSomethingDelay()
{
    // Handled by the built-in DelayScheduler, no Task heap allocation
    await LBTask.Delay(TimeSpan.FromSeconds(3f));
    Console.WriteLine("Triggered after 3 seconds...");
}

2. Frame Sync & Context Configuration (For Independent Driving)

If you want to use LBTask.NextFrame(), or ensure code after await returns to your main thread, you need a synchronization context.

• In Unity / Godot: The engine has already configured the native context for you; just use it directly.
• In Pure C# Environments: You can use the built-in LayerBaseSynchronizationContext:

// 1. Install the context at game/server startup
var ctx = LayerBaseSynchronizationContext.InstallAsCurrent();

// 2. Write frame-split logic
public async LBTask FrameLogic()
{
    Console.WriteLine("Frame 1");
    await LBTask.NextFrame();
    Console.WriteLine("Frame 2 (Returned to main thread)");
}

// 3. Drive it in your main loop (e.g., while(true) or Update)
public void GameLoop()
{
    // Call Update to consume NextFrame and Post-ed callbacks
    ctx.Update(); 
}

Async Tasks with Return Values (LBTask<T>)

In addition to void tasks, LBTask also supports generic return values. It uses LBTaskCompletionSource<T> internally to implement zero-allocation cache recycling:

public async LBTask<int> CalculateHeavyDataAsync()
{
    await LBTask.Delay(TimeSpan.FromSeconds(1));
    return 42;
}

public async LBTask RunTest()
{
    int result = await CalculateHeavyDataAsync();
    Console.WriteLine(result);
}

⚙️ Core API Overview

• LBTask.CompletedTask: Returns a completed LBTask (Zero-Allocation).
• LBTask.Delay(TimeSpan): Provides delay operations based on engine time.
• LBTask.Delay(int milliseconds): Millisecond-based delay.
• LBTask.NextFrame(): Waits until the next engine-driven frame.
• LBTaskCompletionSource<T>: An async state source for manual lifecycle control, recommended for wrapping external cross-thread callbacks.

🔗 About LayerBase

LayerBase.Task is part of the LayerBase high-performance architecture ecosystem. Used alongside the core bus (150M TPS distribution) and Source Generators (Zero-Reflection DI), it unlocks full industrial-grade capabilities.

Project Homepage: LayerBase GitHub Repository