本文共 12236 字，大约阅读时间需要 40 分钟。
孙广东 2014.7.19
无意之间看到了，Unity维基上的一篇文章， 是关于自己写协程的介绍。 觉得很好，这样能更好的了解到协程的运行机制等特性，还是不错的。
原文链接地址如下：
项目地址:
具体的内容如下：
一个简单的协同调度程序。这个协同调度程序允许完全控制一套协同程序的执行机制。 阅读代码也将帮助您了解 协同如何在幕后工作。了解协同程序如何构建.Net 发电机的基础上构建，将允许您将协同支持添加到非Unity的项目。 协同可以yield等待 直到下次更新"yield;", 直到给定的数量的更新已通过 "yield anInt;", 直到给定的秒已通过 "yield aFloat;", 或者直到另一个协程已完成"yield scheduler.StartCoroutine(Coroutine());".StartCoroutine(Coroutine());"。 多个 调度 程序实例支持，并且可以非常有用。协同运行可以运行在一个完全不同的 调度程序实例下 (等待)。 不使用Unity的 YieldInstruction 类，因为我门不能访问这个类所需的调度的内部数据。 语义学Semantics 是和Unity的调度程序略有不同。 例如，在 Unity 中如果你开始协同 它将对其第一次的 yield 立即运行，然而 在自己写的调度程序中，它将不会运行，直到下一次调用 UpdateAllCoroutines。 此功能允许在任何时候的任何代码开始启动一个协程。 同时确保启动协同程序只能运行在特定的时间。 在相同的update协同程序运行之间不应该依赖 更新order。为更深入地了解和学会更多关于 协同程序 如何实现。使用：
using UnityEngine;using System.Collections;////// CoroutineSchedulerTest.cs/// /// Port of the Javascript version from /// http://www.unifycommunity.com/wiki/index.php?title=CoroutineScheduler/// /// Linked list node type used by coroutine scheduler to track scheduling of coroutines./// /// BMBF Researchproject http://playfm.htw-berlin.de/// PlayFM - Serious Games für den IT-gestützten Wissenstransfer im Facility Management /// Gefördert durch das bmb+f - Programm Forschung an Fachhochschulen profUntFH/// /// public class testAPI : MonoBehaviour { CoroutineScheduler scheduler; CoroutineScheduler m_scheduler2; string requestURL = "http://www.my-server.com/cgi-bin/screenshot.pl"; void Start () { scheduler = new CoroutineScheduler (); scheduler.StartCoroutine (MyCoroutine ()); m_scheduler2 = new CoroutineScheduler(); m_scheduler2.StartCoroutine(test()); } IEnumerator MyCoroutine () { Debug.Log ("MyCoroutine: Begin"); yield return 0; // wait for next update Debug.Log ("MyCoroutine: next update;" + Time.time); yield return 2; // wait for 2 updates, same as yield; yield; Debug.Log ("MyCoroutine: After yield 2;" + Time.time); yield return 3.5f; // wait for 3.5 seconds Debug.Log ("MyCoroutine: After 3.5 seconds;" + Time.time); // you can also yield for a coroutine running on a completely different scheduler instance yield return scheduler.StartCoroutine (WaitForMe ()); Debug.Log ("MyCoroutine: After WaitForMe() finished;" + Time.time); } IEnumerator WaitForMe () { yield return 7.8f; // wait for 7.8 seconds before finishing } // Update is called once per void Update () { scheduler.UpdateAllCoroutines (Time.frameCount, Time.time); } IEnumerator test() { // ...set up request var www = new UnityEngine.WWW(requestURL); yield return new UnityWWWYieldWrapper(www); // ...loading complete do some stuff }}Frank.Otto@htw-berlin.de //////
CoroutineScheduler.cs
using System.Collections;using UnityEngine;////// CoroutineScheduler.cs/// /// Port of the Javascript version from /// http://www.unifycommunity.com/wiki/index.php?title=CoroutineScheduler/// /// Linked list node type used by coroutine scheduler to track scheduling of coroutines./// /// /// BMBF Researchproject http://playfm.htw-berlin.de/// PlayFM - Serious Games für den IT-gestützten Wissenstransfer im Facility Management /// Gefördert durch das bmb+f - Programm Forschung an Fachhochschulen profUntFH/// /// public class CoroutineScheduler : MonoBehaviour{ CoroutineNode first = null; int currentFrame; float currentTime; /** * Starts a coroutine, the coroutine does not run immediately but on the * next call to UpdateAllCoroutines. The execution of a coroutine can * be paused at any point using the yield statement. The yield return value * specifies when the coroutine is resumed. */ public CoroutineNode StartCoroutine (IEnumerator fiber) { // if function does not have a yield, fiber will be null and we no-op if (fiber == null) { return null; } // create coroutine node and run until we reach first yield CoroutineNode coroutine = new CoroutineNode (fiber); AddCoroutine (coroutine); return coroutine; } /** * Stops all coroutines running on this behaviour. Use of this method is * discouraged, think of a natural way for your coroutines to finish * on their own instead of being forcefully stopped before they finish. * If you need finer control over stopping coroutines you can use multiple * schedulers. */ public void StopAllCoroutines () { first = null; } /** * Returns true if this scheduler has any coroutines. You can use this to * check if all coroutines have finished or been stopped. */ public bool HasCoroutines () { return first != null; } /** * Runs all active coroutines until their next yield. Caller must provide * the current frame and time. This allows for schedulers to run under * frame and time regimes other than the Unity's main game loop. */ public void UpdateAllCoroutines(int frame, float time) { currentFrame = frame; currentTime = time; CoroutineNode coroutine = this.first; while (coroutine != null) { // store listNext before coroutine finishes and is removed from the list CoroutineNode listNext = coroutine.listNext; if (coroutine.waitForFrame > 0 && frame >= coroutine.waitForFrame) { coroutine.waitForFrame = -1; UpdateCoroutine(coroutine); } else if (coroutine.waitForTime > 0.0f && time >= coroutine.waitForTime) { coroutine.waitForTime = -1.0f; UpdateCoroutine(coroutine); } else if (coroutine.waitForCoroutine != null && coroutine.waitForCoroutine.finished) { coroutine.waitForCoroutine = null; UpdateCoroutine(coroutine); } else if (coroutine.waitForUnityObject != null && coroutine.waitForUnityObject.finished)//lonewolfwilliams { coroutine.waitForUnityObject = null; UpdateCoroutine(coroutine); } else if (coroutine.waitForFrame == -1 && coroutine.waitForTime == -1.0f && coroutine.waitForCoroutine == null && coroutine.waitForUnityObject == null) { // initial update UpdateCoroutine(coroutine); } coroutine = listNext; } } /** * Executes coroutine until next yield. If coroutine has finished, flags * it as finished and removes it from scheduler list. */ private void UpdateCoroutine(CoroutineNode coroutine) { IEnumerator fiber = coroutine.fiber; if (coroutine.fiber.MoveNext()) { System.Object yieldCommand = fiber.Current == null ? (System.Object)1 : fiber.Current; if (yieldCommand.GetType() == typeof(int)) { coroutine.waitForFrame = (int)yieldCommand; coroutine.waitForFrame += (int)currentFrame; } else if (yieldCommand.GetType() == typeof(float)) { coroutine.waitForTime = (float)yieldCommand; coroutine.waitForTime += (float)currentTime; } else if (yieldCommand.GetType() == typeof(CoroutineNode)) { coroutine.waitForCoroutine = (CoroutineNode)yieldCommand; } else if (yieldCommand is IYieldWrapper) //lonewolfwilliams { coroutine.waitForUnityObject = yieldCommand as IYieldWrapper; } else { throw new System.ArgumentException("CoroutineScheduler: Unexpected coroutine yield type: " + yieldCommand.GetType()); //this is an alternative if you don't have access to the function passed to the couroutineScheduler - maybe it's //precompiled in a dll for example - remember you will have to add a case every time you add a wrapper :/ /* var commandType = yieldCommand.GetType(); if(commandType == typeof(UnityEngine.WWW)) { coroutine.waitForUnityObject = new UnityWWWWrapper(yieldCommand as UnityEngine.WWW); } else if(commandType == typeof(UnityEngine.AsyncOperation)) { coroutine.waitForUnityObject = new UnityASyncOpWrapper(yieldCommand as UnityEngine.AsyncOperation); } else if(commandType == typeof(UnityEngine.AssetBundleRequest)) { coroutine.waitForUnityObject = new UnityAssetBundleRequestWrapper(yieldCommand as UnityEngine.AssetBundleRequest); } else { throw new System.ArgumentException("CoroutineScheduler: Unexpected coroutine yield type: " + yieldCommand.GetType()); } */ } } else { // coroutine finished coroutine.finished = true; RemoveCoroutine(coroutine); } } private void AddCoroutine (CoroutineNode coroutine) { if (this.first != null) { coroutine.listNext = this.first; first.listPrevious = coroutine; } first = coroutine; } private void RemoveCoroutine (CoroutineNode coroutine) { if (this.first == coroutine) { // remove first this.first = coroutine.listNext; } else { // not head of list if (coroutine.listNext != null) { // remove between coroutine.listPrevious.listNext = coroutine.listNext; coroutine.listNext.listPrevious = coroutine.listPrevious; } else if (coroutine.listPrevious != null) { // and listNext is null coroutine.listPrevious.listNext = null; // remove last } } coroutine.listPrevious = null; coroutine.listNext = null; } }//classFrank.Otto@htw-berlin.de ////// /// A simple coroutine scheduler. Coroutines can yield until the next update/// "yield;", until a given number of updates "yield anInt", until a given/// amount of seconds "yield aFloat;", or until another coroutine has finished/// "yield scheduler.StartCoroutine(Coroutine())"./// /// Multiple scheduler instances are supported and can be very useful. A/// coroutine running under one scheduler can yield (wait) for a coroutine/// running under a completely different scheduler instance./// /// Unity's YieldInstruction classes are not used because I cannot/// access their internal data needed for scheduling. Semantics are slightly/// different from Unity's scheduler. For example, in Unity if you start a/// coroutine it will run up to its first yield immediately, while in this/// scheduler it will not run until the next time UpdateAllCoroutines is called./// This feature allows any code to start coroutines at any time, while/// making sure the started coroutines only run at specific times./// /// You should not depend on update order between coroutines running on the same/// update. For example, StartCoroutine(A), StartCoroutine(B), StartCoroutine(C)/// where A, B, C => while(true) { print(A|B|C); yield; }, do not expect "ABC" or/// "CBA" or any other specific ordering.///
CoroutineNode.cs
using System.Collections;using UnityEngine;////// CoroutineNode.cs/// /// Port of the Javascript version from /// http://www.unifycommunity.com/wiki/index.php?title=CoroutineScheduler/// /// Linked list node type used by coroutine scheduler to track scheduling of coroutines./// /// BMBF Researchproject http://playfm.htw-berlin.de/// PlayFM - Serious Games für den IT-gestützten Wissenstransfer im Facility Management /// Gefördert durch das bmb+f - Programm Forschung an Fachhochschulen profUntFH/// /// public class CoroutineNode{ public CoroutineNode listPrevious = null; public CoroutineNode listNext = null; public IEnumerator fiber; public bool finished = false; public int waitForFrame = -1; public float waitForTime = -1.0f; public CoroutineNode waitForCoroutine; public IYieldWrapper waitForUnityObject; //lonewolfwilliams public CoroutineNode(IEnumerator _fiber) { this.fiber = _fiber; }}Frank.Otto@htw-berlin.de //////
IYieldWrapper.cs
/* * gareth williams * http://www.lonewolfwilliams.com */public interface IYieldWrapper{ bool finished { get; }} Example Wrappers
Below are some examples of wrappers I have used, in fact they have almost identical signatures so a more generic implementation could probably be written ^_^
using System;using System.Collections.Generic;using System.Linq;using System.Text;/** Gareth Williams* http://www.lonewolfwilliams.com*/class UnityASyncOpWrapper : IYieldWrapper{ private UnityEngine.AsyncOperation m_UnityObject; public bool finished { get { return m_UnityObject.isDone; } } public UnityASyncOpWrapper(UnityEngine.AsyncOperation wraps) { m_UnityObject = wraps; }} UnityWWWYieldWrapper using System;using System.Collections.Generic;using System.Linq;using System.Text; /* * Gareth Williams * http://www.lonewolfwilliams.com */ public class UnityWWWYieldWrapper : IYieldWrapper{ private UnityEngine.WWW m_UnityObject; public bool finished { get { return m_UnityObject.isDone; } } public UnityWWWYieldWrapper(UnityEngine.WWW wraps) { m_UnityObject = wraps; }} 转载地址：http://reoa.baihongyu.com/