Loom主线程和子线程交叉调用主线

客官里面请 Unity主线程和子线程交叉调用（二)Unity主线程和子线程交叉调用（三）

某些项目，在某些特殊场合游戏开发素材，有一代码段混合了耗时代码和Unity api。如下面这种情况

MainFunction
{
    //这个函数会进行大量文件读写操作
    DownloadFile1();
    //这个函数是unity函数
    UnityFunction1();
    DownloadFile2();
    UnityFunction2();
    DownloadFile3();
    UnityFunction3();
    ......
}

如果必须保证LoadLocalFile() 不“假死”，不管是使用带参回调unity 线程游戏评测，或事件注册，都会导致代码难以编写和阅读。 参考Loom,网上的代码五花八门unity 线程，甚至还有错误的，我做了一些修改，核心思路是把主线程需要执行的任务放在待消费列表中。 实际项目中可以在MainThreadTask结构中定义自己的各种调度排序策略(类似操作系统进程调度)
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System;
using System.Threading;
using System.Linq;
public class Loom : MonoBehaviour
{
    public struct MainThreadTask
    {
        //何时运行该函数
        public System.DateTime time;
        public Action action;
    }
    public static int maxThreads = 8;
    private int hasThreadCount;
    private static Loom current;
    private static void CheckInit()
    {
        if (current == null)
        {
            var g = new GameObject("Loom");
            current = g.AddComponent<Loom>();
            UnityEngine.Object.DontDestroyOnLoad(g);
        }
    }
    public static void RunOnMainThread(Action action, float time = 0)
    {
        CheckInit();
        if(time<0)
        {
            Debug.LogError("time参数错误 函数不会被执行");
            return;
        }
        if (time != 0)
        {
            lock (current.allDelayed)
            {
                current.allDelayed.Add(new MainThreadTask { time = System.DateTime.Now.AddSeconds(time), action = action });
            }
        }
        else
        {
            lock (current.allNoDelayed)
            {
                current.allNoDelayed.Add(new MainThreadTask {time = System.DateTime.Now, action = action });
            }
        }
    }
    public static void RunOnAsync(Action active)
    {
        CheckInit();
        while (current.hasThreadCount >= maxThreads)
        {
            Thread.Sleep(100);
        }
        Interlocked.Increment(ref current.hasThreadCount);
        ThreadPool.QueueUserWorkItem(RunAction, active);
    }
    private static void RunAction(object action)
    {
        try
        {
            ((Action)action)();
        }
        catch(Exception e)
        {
            Debug.LogError(e.ToString());
        }
        finally
        {
            Interlocked.Decrement(ref current.hasThreadCount);
        }
    }
    //延时和不延时区分开来的目的是保证不延时的函数立即执行 且减少linq查询
    private List<MainThreadTask> allDelayed = new List<MainThreadTask>();
    private List<MainThreadTask> currentDelayed = new List<MainThreadTask>();
    private List<MainThreadTask> allNoDelayed = new List<MainThreadTask>();
    private List<MainThreadTask> currentNoDelayed = new List<MainThreadTask>();
    // 消费主线程任务
    private void Update()
    {
        if (allNoDelayed.Count > 0)
        {
            lock (allNoDelayed)
            {
                currentNoDelayed.Clear();
                currentNoDelayed.AddRange(allNoDelayed);
                allNoDelayed.Clear();
            }
            for (int i = 0; i < currentNoDelayed.Count; i++)
            {
                currentNoDelayed[i].action();
            }
        }
        if (allDelayed.Count > 0)
        {
            lock (allDelayed)
            {
                currentDelayed.Clear();
                currentDelayed.AddRange(allDelayed.Where(d => d.time <= System.DateTime.Now));
                for (int i = 0; i < currentDelayed.Count; i++)
                {
                    allDelayed.Remove(currentDelayed[i]);
                }
            }
            for (int i = 0; i < currentDelayed.Count; i++)
            {
                currentDelayed[i].action();
            }
        }
    }
}

使用方式
void Start()
    {
        Loom.RunOnAsync(MainFun);
    }
    public void MainFun()
    {
        Loom.RunOnMainThread(FirstTest);
        Thread.Sleep(100);
        Loom.RunOnMainThread(()=> { Test("2"); });
        Thread.Sleep(100);
        Loom.RunOnMainThread(() => { Test("4"); },1f);
        Loom.RunOnMainThread(() => { Test("3"); });
    }
    private void FirstTest()
    {
        Debug.Log("1:" + gameObject.name);
    }
    private void Test(string time)
    {
        Debug.Log(time + "：" + gameObject.name);
    }

执行结果

文章来源:https://developer.unity.cn/projects/5f3fdb6cedbc2a00205354cd