lua协程实现异步编程模式

异步编程模式只是一个代码结构，c#中的async/await的写法就是异步编程模式，这边就是通过协程来达到和async/await类似的效果。

异步编程模式写法1：资源分帧加载

这边运行环境用的是：Unity+xLua

lua脚本：Assets/Lua/Test9.lua.txt

local _Time = CS.UnityEngine.Time

local function WaitOneFrame()
    local co, isMain = coroutine.running()
    MonoInst:AddCallback(function()
        coroutine.resume(co)
    end)
    local result = coroutine.yield()
end

local function LoadOneResPerFrame()
    print("加载资源1, frame:", _Time.frameCount)
    WaitOneFrame()
    print("加载资源2, frame:", _Time.frameCount)
    WaitOneFrame()
    print("加载资源3, frame:", _Time.frameCount)
end

local co = coroutine.create(LoadOneResPerFrame)
local isSucc, result = coroutine.resume(co)
print("main end:", isSucc, result)

Test9.cs

public class Test9 : MonoBehaviour
{
    private LuaEnv m_LuaEnv;

    private Queue<Action> m_PendingQueue = new Queue<Action>();
    private Queue<Action> m_RunningQueue = new Queue<Action>();

    void Start()
    {
        m_LuaEnv = new LuaEnv();
        m_LuaEnv.AddLoader((ref string filePath) =>
        {
            filePath = filePath.Replace('.', '/');
            filePath = $"Assets/{filePath}.lua.txt";
            var txtAsset = AssetDatabase.LoadAssetAtPath<TextAsset>(filePath);
            return Encoding.UTF8.GetBytes(txtAsset.text);
        });
        m_LuaEnv.Global.Set("MonoInst", this);
        m_LuaEnv.DoString("require('Lua.Test9')");
    }

    void OnDestroy()
    {
        if (null != m_LuaEnv)
            m_LuaEnv.Dispose();
    }

    public void AddCallback(Action callback)
    {
        m_PendingQueue.Enqueue(callback);
    }

    void Update()
    {
        while (m_RunningQueue.Count > 0)
        {
            var act = m_RunningQueue.Dequeue();
            act();
        }
        while (m_PendingQueue.Count > 0)
        {
            var act = m_PendingQueue.Dequeue();
            m_RunningQueue.Enqueue(act);
        }
    }

}