Unity3d：GameFramework解析：实体，对象池，资源管理，获取计数，引用计数，自动释放

基本概念

1.GF万物基于引用池IReference
2.ObjectBase : IReference类的m_Target持有unity中Mono，资源，GameObejct
3.AssetObject : ObjectBase类m_Target持有Assetbundle中的Asset，具有获取，引用两个计数管理释放
4.ResourceObject : ObjectBase类m_Target持有Assetbundle，具有获取，引用两个计数管理释放
5.EntityInstanceObject : ObjectBase类m_Target指向Assetbundle中的Asset实例化后的GameObject，内部m_EntityAsset也是Assetbundle中的Asset
6.对象池具有按照间隔自动释放无用对象，对于实体，获取为0，即无用对象；对于AssetObject，ResourceObject要获取为0，父依赖（自己被别依赖）为0，即无用
7.引用的概念为资源被依赖，例如bundleA依赖bundleB，于是bundleB的引用=1
8.获取的概念：针对资源为对象再派生（关联）出别的对象，例如ResourceObjectA派生出AssetObjectA，即ResourceObjectA获取为1；AssetObjectA再派生出EntityInstanceObjectA，AssetObjectA的获取为1

对象池创建

InstancePool

只能单获取，即不能对一个对象反复Spawn

m_InstancePool = objectPoolManager.CreateSingleSpawnObjectPool<EntityInstanceObject>(Utility.Text.Format("Entity Instance Pool ({0})", name), instanceCapacity, instanceExpireTime, instancePriority);

AssetPool与ResourceObject

public void SetObjectPoolManager(IObjectPoolManager objectPoolManager)
{
    m_AssetPool = objectPoolManager.CreateMultiSpawnObjectPool<AssetObject>("Asset Pool");
    m_ResourcePool = objectPoolManager.CreateMultiSpawnObjectPool<ResourceObject>("Resource Pool");
}

EntityInstanceObject实体对象

1.每次使用看实体对象池中有无，有是指存在空闲未使用实体对象，取出来用
2.没有的话，需要从资源加载流程中走一遍

释放时

UnityGameFramework.Runtime.DefaultEntityHelper.ReleaseEntity

        /// <summary>
        /// 释放实体。
        /// </summary>
        /// <param name="entityAsset">要释放的实体资源。</param>
        /// <param name="entityInstance">要释放的实体实例。</param>
        public override void ReleaseEntity(object entityAsset, object entityInstance)
        {
            m_ResourceComponent.UnloadAsset(entityAsset);
            Destroy((Object)entityInstance);
        }

1.AssetPool中把entityAsset的获取-1
2.销毁asset实例出来的GameObject

ResourceObject

何时引用+1

在assetA加载完，assetA的依赖asset的bundle引用+1。注意是依赖的asset的bundle，自身的bundle并不会引用+1
GameFramework.Resource.ResourceManager.ResourceLoader.LoadResourceAgent.OnLoadResourceAgentHelperLoadComplete

foreach (object dependencyAsset in dependencyAssets)
{
    object dependencyResource = null;
    if (m_ResourceLoader.m_AssetToResourceMap.TryGetValue(dependencyAsset, out dependencyResource))
    {
        m_Task.ResourceObject.AddDependencyResource(dependencyResource); //所有依赖这个asset的resource引用+1
    }

同时被依赖的bundleB加入到主bundleA的ResourceObject依赖列表中
GameFramework.Resource.ResourceManager.ResourceLoader.ResourceObject.AddDependencyResource

m_DependencyResources.Add(dependencyResource);

何时引用-1

bundle被释放时，子依赖bundle引用-1
GameFramework.Resource.ResourceManager.ResourceLoader.ResourceObject.Release

 foreach (object dependencyResource in m_DependencyResources)
{
    int referenceCount = 0;
    if (m_ResourceLoader.m_ResourceDependencyCount.TryGetValue(dependencyResource, out referenceCount))
    {
        m_ResourceLoader.m_ResourceDependencyCount[dependencyResource] = referenceCount - 1;
        //只会-1，不会对为 0 的Assetbundle进行卸载
    }

何时获取+1

bundleA中获取assetA时，获取+1。此时有有两种情况，
1.执行加载asset任务时，主bundle已加载，从ResourcePool中获取
GameFramework.Resource.ResourceManager.ResourceLoader.LoadResourceAgent.Start

ResourceObject resourceObject = m_ResourceLoader.m_ResourcePool.Spawn(resourceName);
if (resourceObject != null)
{
    GameFrameworkLog.Info("ResourcePool获取到了{0}，说明asset:{1}的bundle已经加好了，返回bundle", resourceName, m_Task.AssetName);
    //从resource对象池中取出，说明之前加载过Assetbundle，任务可以接着执行
    OnResourceObjectReady(resourceObject);
    return StartTaskStatus.CanResume;
}

2.bundle未加载，加载完后注册入对象池，获取+1
GameFramework.Resource.ResourceManager.ResourceLoader.LoadResourceAgent.OnLoadResourceAgentHelperReadFileComplete

private void OnLoadResourceAgentHelperReadFileComplete(object sender, LoadResourceAgentHelperReadFileCompleteEventArgs e)
{
    GameFrameworkLog.Info("Assetbundle加载完成：{0}", m_Task.ResourceInfo.ResourceName.Name);
    ResourceObject resourceObject = ResourceObject.Create(m_Task.ResourceInfo.ResourceName.Name, e.Resource, m_ResourceHelper, m_ResourceLoader);
    m_ResourceLoader.m_ResourcePool.Register(resourceObject, true);
    s_LoadingResourceNames.Remove(m_Task.ResourceInfo.ResourceName.Name);
    OnResourceObjectReady(resourceObject);
}

何时获取-1

GameFramework.Resource.ResourceManager.ResourceLoader.AssetObject.Release

m_ResourceLoader.m_ResourcePool.Unspawn(m_Resource);

AssetObject

何时引用+1

assetA新加载完成时，创建AssetObjectA，把子依赖asset引用+1
GameFramework.Resource.ResourceManager.ResourceLoader.AssetObject.Create

//所有依赖的asset 引用+1，它自己次数不会+1
foreach (object dependencyAsset in dependencyAssets)
{
    int referenceCount = 0;
    GameFrameworkLog.Info("AssetObject创建-->{0}引用次数+1", dependencyAsset);
    if (resourceLoader.m_AssetDependencyCount.TryGetValue(dependencyAsset, out referenceCount))
    {
        resourceLoader.m_AssetDependencyCount[dependencyAsset] = referenceCount + 1;
    }
    else
    {
        resourceLoader.m_AssetDependencyCount.Add(dependencyAsset, 1);
    }
}

何时引用-1

AssetObjectA释放时，把所有子依赖资源-1。这里只会找直接子依赖（子节点），不会找到孙节点上
GameFramework.Resource.ResourceManager.ResourceLoader.AssetObject.Release

foreach (object dependencyAsset in m_DependencyAssets)
{
    int referenceCount = 0;
    if (m_ResourceLoader.m_AssetDependencyCount.TryGetValue(dependencyAsset, out referenceCount))
    {
        m_ResourceLoader.m_AssetDependencyCount[dependencyAsset] = referenceCount - 1;
        //子依赖的asset -1
    }

何时获取+1

AssetObject的获取，是为了给实例对象实例化。两种情况下
1.任务执行时，AssetPool有，直接返回，获取+1
GameFramework.Resource.ResourceManager.ResourceLoader.LoadResourceAgent.Start

//从对象池里拿一个 
AssetObject assetObject = m_ResourceLoader.m_AssetPool.Spawn(m_Task.AssetName);
if (assetObject != null)
{
    //说明资源之前加载过，且在AssetObject缓存池中
    //一旦成功执行Spawn，Spawn+1，在释放资源时不为0会跳过
    GameFrameworkLog.Info("AssetPool获取到了{0}，不需要加载，直接返回asset", m_Task.AssetName);
    //如果是实体，实例化asset，并且新建一个实体对象
    OnAssetObjectReady(assetObject);
    return StartTaskStatus.Done;
}

2.AssetPool没有，从Assetbundle中加载完成asset，创建新AssetObject，并注册进入AssetPool，获取+1
GameFramework.Resource.ResourceManager.ResourceLoader.LoadResourceAgent.OnLoadResourceAgentHelperLoadComplete

            assetObject = AssetObject.Create(m_Task.AssetName, e.Asset, dependencyAssets, m_Task.ResourceObject.Target, m_ResourceHelper, m_ResourceLoader);
            GameFrameworkLog.Info("asset-->{0}加载完成,并且创建AssetObject到m_AssetPool缓冲池中", m_Task.AssetName);
            m_ResourceLoader.m_AssetPool.Register(assetObject, true);

何时获取-1

EntityInstanceObject释放时
UnityGameFramework.Runtime.DefaultEntityHelper.ReleaseEntity

        /// <summary>
        /// 释放实体。
        /// </summary>
        /// <param name="entityAsset">要释放的实体资源。</param>
        /// <param name="entityInstance">要释放的实体实例。</param>
        public override void ReleaseEntity(object entityAsset, object entityInstance)
        {
            m_ResourceComponent.UnloadAsset(entityAsset);
            Destroy((Object)entityInstance);
        }

加载实体创建各个asset任务

加载一个实体，一个asset作为主任务，asset依赖的各个asset作为依赖任务

单个asest任务加载任务执行

任务

任务派生LoadAssetTask，LoadDependencyAssetTask，LoadSceneTask

任务完成的标志

资源准备好，即任务完成。不管是是从AssetPool中获取，还是异步加载完成

private void OnAssetObjectReady(AssetObject assetObject)
{
    m_Helper.Reset();
 
    object asset = assetObject.Target;
    if (m_Task.IsScene)
    {
        m_ResourceLoader.m_SceneToAssetMap.Add(m_Task.AssetName, asset);
    }
 
    m_Task.OnLoadAssetSuccess(this, asset, (float)(DateTime.UtcNow - m_Task.StartTime).TotalSeconds);
    m_Task.Done = true;
}

自动释放

隐藏某实体时，在对象池自动释放中，如果改实体池依赖的asset获取为0，再判断出bundle获取为0，触发assetbundle.Unload(true)，释放内存