Unity多線程管理

游戲中我們有許多地方還是有需求要開(kāi)啟多線程，例如下載文件，解壓文件等操作呛伴，我們需要在Unity下使用
多線程，那我們?nèi)绾文芨奖愕墓芾矶嗑€程呢谒所？

目前主要需要解決一下幾個(gè)問(wèn)題：

1. 統(tǒng)一開(kāi)啟子線程热康，防止多線程濫用
2. 子線程中如何回調(diào)主線程

我目前的解決方案

• 所有需要異步處理的任務(wù)，都繼承AsyncTask劣领。
• AsyncTask封裝了執(zhí)行過(guò)程姐军，方便對(duì)任務(wù)的控制。
• 所有需要回調(diào)主線程的地方尖淘，統(tǒng)一添加Action奕锌。由主線程逐幀調(diào)用

代碼如下：

using System;
using System.Collections;
using System.Collections.Generic;
using System.Threading;
using UnityEngine;
using LuaFramework;

/// <summary>
/// 異步任務(wù)，交給子線程執(zhí)行
/// </summary>
public abstract class AsyncTask
{
    // multiThreadMgr
    protected MultiThreadManager MultiThreadMgr {
        get {
            return AppFacade.Instance.GetManager<MultiThreadManager> (ManagerName.MultiThread);
        }
    } 

    /// <summary>
    /// 執(zhí)行任務(wù)
    /// </summary>
    public void Execute() {
        try {
            Run();
        } finally {
            MultiThreadMgr.FinishTask (this);
        }
    }

    /// <summary>
    /// 關(guān)閉執(zhí)行
    /// </summary>
    public abstract void Close ();

    /// <summary>
    /// 開(kāi)始運(yùn)行
    /// </summary>
    public abstract void Run ();
}

/// <summary>
/// 多線程管理器
/// </summary>
public class MultiThreadManager : Manager
{
    // 需要在主線程執(zhí)行的操作
    static List<Action> actions = new List<Action> ();
    static List<Action> runningActions = new List<Action> ();
    static object obj = new object();

    // 異步任務(wù)隊(duì)列
    static List<AsyncTask> taskList = new List<AsyncTask> ();

    /// <summary>
    /// 在主線程中執(zhí)行
    /// </summary>
    /// <param name="action">Action.</param>
    public void RunOnMainThread (Action action)
    {
        lock (obj) {
            actions.Add (action);
        }
    }

    /// <summary>
    /// 添加異步任務(wù)
    /// </summary>
    /// <param name="runnable">Runnable.</param>
    public void AddAsyncTask (AsyncTask runnable)
    {
        Debug.Log("AddTask:" + runnable.ToString());
        taskList.Add (runnable);
        Thread thread = new Thread (runnable.Execute);
        thread.IsBackground = true;
        thread.Start ();
    }

    /// <summary>
    /// 完成異步任務(wù)
    /// </summary>
    /// <param name="runnable">Runnable.</param>
    public void FinishTask (AsyncTask runnable)
    {
        taskList.Remove (runnable);
        Debug.Log ("RemoveTask:" + runnable.ToString () + "," + taskList.Count);
    }

    /// <summary>
    /// 主線程更新
    /// </summary>
    void Update ()
    {
        lock (obj) {
            runningActions.Clear ();
            runningActions.AddRange (actions);
            actions.Clear ();
        }

        // 處理主線程事件
        if (runningActions.Count > 0) {
            foreach(Action action in runningActions) {
                action ();
            }
        }
        runningActions.Clear ();
    }

    void OnDestroy() {
        for (int i = 0; i < taskList.Count; i++) {
            taskList [i].Close ();
        }
    }
}