多线程接触

简介

自己开始接触一下多线程

Thread

• 属性：主线程id为1，优先级Lowest，IsThreadPoolThread为false，IsBackground为false
• 一个线程默认占用1M的堆栈空间，也可以修改

方法：

简单实例

• 创建开始，有参函数参数只能有一个，而且是object类型，但是既然都是object了，就可以改变一下传更多参数

      void Start () {
  
          InitThread();
          Debug.LogError("MainThread:" + Thread.CurrentThread.ManagedThreadId.ToString());
      }
      
      private void InitThread()
      {
          Thread t1 = new Thread(Start1);
          t1.Start();
  
          Thread t2 = new Thread(Start2);
          t2.Start("LOG");
  
          Thread t3 = new Thread(Start3);
          t3.Start(new MoreParams(10086, "hah"));
      }
  
      private void Start1()
      {
          Debug.LogError("Start1:" + Thread.CurrentThread.ManagedThreadId.ToString());
      }
      
      //单个参数
      private void Start2(object log)
      {
          Debug.LogError("Start2:" + Thread.CurrentThread.ManagedThreadId.ToString()+log);
      }
      
      //多个参数
      private void Start3(object p)
      {
          MoreParams moreparams= (MoreParams)p;
          Debug.LogError("Start3:" + Thread.CurrentThread.ManagedThreadId.ToString());
          Debug.LogError("p1:" + moreparams.p1 + "_p2:" + moreparams.p2);
      }
  
      class MoreParams
      {
          public int p1;
          public string p2;
          public MoreParams(int p1, string p2)
          {
              this.p1 = p1;
              this.p2 = p2;
          }
      }
  

  输出：每次运行，主线程id为1，新线程的id都不同，会累加，输出顺序不固定

threadpool

• 线程完成任务不会自行销毁，而是挂起状态回到线程池

• 向线程池发出请求时，挂起线程会再次激活

• 线程池线程默认为后台线程

Loom

• 在Update中不断检查需要回调的Action进行加锁回调，回调序列作为静态数据保存，可任意添加
• 开启一个线程然后在Loom.RunAsyn()中调用需要回到Unity主线程更新界面时调用QueueOnMainThread（）即可。简单好用。

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

public class Loom : MonoBehaviour
{
    public static int maxThreads = 8;
    private static int numThreads;

    private static Loom _current;
    //private int _count;
    public static Loom Current
    {
        get
        {
            Initialize();
            return _current;
        }
    }

    private void Awake()
    {
        _current = this;
        initialized = true;
    }

    private static bool initialized;

    public static void Initialize()
    {
        if (!initialized)
        {

            if (!Application.isPlaying)
                return;
            initialized = true;
            var g = new GameObject("Loom");
            _current = g.AddComponent<Loom>();
#if !ARTIST_BUILD
            UnityEngine.Object.DontDestroyOnLoad(g);
#endif
        }

    }
    public struct NoDelayedQueueItem
    {
        public Action<object> action;
        public object param;
    }

    private List<NoDelayedQueueItem> _actions = new List<NoDelayedQueueItem>();
    public struct DelayedQueueItem
    {
        public float time;
        public Action<object> action;
        public object param;
    }
    private List<DelayedQueueItem> _delayed = new List<DelayedQueueItem>();
    private List<DelayedQueueItem> _currentDelayed = new List<DelayedQueueItem>();

    public static void QueueOnMainThread(Action<object> taction, object tparam)
    {
        QueueOnMainThread(taction, tparam, 0f);
    }
    public static void QueueOnMainThread(Action<object> taction, object tparam, float time)
    {
        if (time != 0)
        {
            lock (Current._delayed)
            {
                Current._delayed.Add(new DelayedQueueItem { time = Time.time + time, action = taction, param = tparam });
            }
        }
        else
        {
            lock (Current._actions)
            {
                Current._actions.Add(new NoDelayedQueueItem { action = taction, param = tparam });
            }
        }
    }

    public static Thread RunAsync(Action a)
    {
        Initialize();
        while (numThreads >= maxThreads)
        {
            Thread.Sleep(100);
        }
        Interlocked.Increment(ref numThreads);
        ThreadPool.QueueUserWorkItem(RunAction, a);
        return null;
    }

    private static void RunAction(object action)
    {
        try
        {
            ((Action)action)();
        }
        catch
        {
        }
        finally
        {
            Interlocked.Decrement(ref numThreads);
        }

    }

    private void OnDisable()
    {
        if (_current == this)
        {

            _current = null;
        }
    }



    // Use this for initialization
    private void Start()
    {

    }

    private List<NoDelayedQueueItem> _currentActions = new List<NoDelayedQueueItem>();

    // Update is called once per frame
    private void Update()
    {
        if (_actions.Count > 0)
        {
            lock (_actions)
            {
                _currentActions.Clear();
                _currentActions.AddRange(_actions);
                _actions.Clear();
            }
            for (int i = 0; i < _currentActions.Count; i++)
            {
                _currentActions[i].action(_currentActions[i].param);
            }
        }

        if (_delayed.Count > 0)
        {
            lock (_delayed)
            {
                _currentDelayed.Clear();
                _currentDelayed.AddRange(_delayed.Where(d => d.time <= Time.time));
                for (int i = 0; i < _currentDelayed.Count; i++)
                {
                    _delayed.Remove(_currentDelayed[i]);
                }
            }

            for (int i = 0; i < _currentDelayed.Count; i++)
            {
                _currentDelayed[i].action(_currentDelayed[i].param);
            }
        }
    }
}

调用：

//创建线程
Loom.RunAsync(() => {
    Thread thread = new Thread(Start1);
    thread.Start();
});

//回调        
Loom.QueueOnMainThread((param) =>
{
    Debug.LogError("1");
}, null);