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@@ -604,3 +604,79 @@ gc.AllowParallelGC=True
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3. 采用对象池，不频繁清理和生成大的对象
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最厉害的还是改源码... 比如将标记那块改为无锁的
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+
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+## 智能指针
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+
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+`TWeakObjectPtr` 继承自 `FWeakObjectPtr`，存储 `UObject` 在 `GUObjectArray` 的 `Index` 和 `SerialNumber`，而不是直接引用 `UObject`
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+
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+```cpp
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+void FWeakObjectPtr::operator=(const class UObject *Object)
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+{
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+ if (Object)
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+ {
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+ ObjectIndex = GUObjectArray.ObjectToIndex((UObjectBase*)Object);
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+ ObjectSerialNumber = GUObjectArray.AllocateSerialNumber(ObjectIndex);
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+ checkSlow(SerialNumbersMatch());
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+ }
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+ else
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+ {
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+ Reset();
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+ }
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+}
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+```
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+
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+`TStrongObjectPtr` 自 `FGCObject` 的 `ReferenceCollector`，通过 `FGCObject` 的构造将 `UObject` 添加到 `GGCObjectReferencer` 中
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+
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+因为 `GGCObjectReferencer` 是 `AddToRoot` 的，所以不会被销毁，那么该智能指针指向的 `UObject` 也不会被销毁，在析构的时候将 `UObject` 从 `GGCObjectReferencer` 销毁即可
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+
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+```cpp
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+void FGCObject::RegisterGCObject()
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+{
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+ if (!IsEngineExitRequested() && !bReferenceAdded)
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+ {
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+ StaticInit();
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+ GGCObjectReferencer->AddObject(this);
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+ bReferenceAdded = true;
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+ }
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+}
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+void FGCObject::StaticInit()
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+{
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+ if (GGCObjectReferencer == nullptr)
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+ {
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+ GGCObjectReferencer = NewObject<UGCObjectReferencer>();
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+ GGCObjectReferencer->AddToRoot();
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+ }
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+}
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+```
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+
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+`TSoftObjectPtr` 组合 `FSoftObjectPtr` 使用，既不是强引用指针也不是软引用指针
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+
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+主要功能在 `TPersistentObjectPtr` 类中实现，该类维护一个 `WeakPtr` 用于记录指向的对象，存储一个 `TObjectID` 也就是 `FSoftObjectPath` 对象用于记录目标对象的资产路径
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+
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+```cpp
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+struct FSoftObjectPtr : public TPersistentObjectPtr<FSoftObjectPath>;
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+
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+template<class TObjectID>
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+struct TPersistentObjectPtr
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+{
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+private:
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+ mutable FWeakObjectPtr WeakPtr;
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+ TObjectID ObjectID;
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+}
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+```
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+
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+通过 `TPersistentObjectPtr` 获取对象可以窥见 `TSoftObjectPtr` 的核心功能
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+
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+```cpp
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+FORCEINLINE UObject* Get() const
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+{
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+ UObject* Object = WeakPtr.Get();
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+ if (!Object && ObjectID.IsValid())
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+ {
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+ Object = ObjectID.ResolveObject();
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+ WeakPtr = Object;
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+ return ::GetValid(Object);
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+ }
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+ return Object;
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+}
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+```
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NiceTry12138