FGCObject Class Reference

#include <GCObject.h>

Inheritance diagram for FGCObject:

Public Types
enum class	EFlags : uint32 { None = 0 , RegisterLater = 1 << 0 , AddStableNativeReferencesOnly = 1 << 1 }

Public Member Functions
	FGCObject ()
	FGCObject (const FGCObject &Other)
	FGCObject (FGCObject &&Other)
	FGCObject (EFlags Flags)
virtual	~FGCObject ()
FGCObject &	operator= (const FGCObject &)
FGCObject &	operator= (FGCObject &&)
COREUOBJECT_API void	RegisterGCObject ()
COREUOBJECT_API void	UnregisterGCObject ()
virtual void	AddReferencedObjects (FReferenceCollector &Collector)=0
virtual FString	GetReferencerName () const =0
virtual bool	GetReferencerPropertyName (UObject *Object, FString &OutPropertyName) const

Static Public Member Functions
static COREUOBJECT_API void	StaticInit ()

Static Public Attributes
static COREUOBJECT_API UGCObjectReferencer *	GGCObjectReferencer = nullptr

Detailed Description

This class provides common registration for garbage collection for non-UObject classes. It is an abstract base class requiring you to implement the AddReferencedObjects() method.

Note: FGCObject instances are not trivially relocatable, and are therefore not suited for being stored in Unreal container types by value. For example, this won't work: class FMyClass : public FGCObject {}; struct FSomeStruct { TArray<FMyClass> Instances; // Storing anything here might crash GC at // reachability analysis };

Member Enumeration Documentation

EFlags

enum class FGCObject::EFlags : uint32

strong

Enumerator
None
RegisterLater	Manually call RegisterGCObject() later to avoid collecting references from empty / late-initialized FGCObjects
AddStableNativeReferencesOnly	Declare that AddReferencedObjects only calls FReferenceCollector::AddStableReference*() functions instead of the older FReferenceCollector::AddReferenceObject*() and only adds native references. Allows gathering initial references before reachability analysis starts.

Constructor & Destructor Documentation

FGCObject() [1/4]

FGCObject::FGCObject ( )

inline

Tells the global object that forwards AddReferencedObjects calls on to objects that a new object is requiring AddReferencedObjects call.

FGCObject() [2/4]

FGCObject::FGCObject ( const FGCObject &  Other )

inline

FGCObject() [3/4]

FGCObject::FGCObject ( FGCObject &&  Other )

inline

FGCObject() [4/4]

FGCObject::FGCObject ( EFlags  Flags )

inlineexplicit

~FGCObject()

virtual FGCObject::~FGCObject ( )

inlinevirtual

Member Function Documentation

AddReferencedObjects()

virtual void FGCObject::AddReferencedObjects ( FReferenceCollector &  Collector )

pure virtual

Pure virtual that must be overloaded by the inheriting class. Use this method to serialize any UObjects contained that you wish to keep around.

Parameters

Collector

The collector of referenced objects.

Implemented in Audio::FMixerDevice, Audio::FSoundSourceDecoder, FARSupportInterface, FAsyncPackage, PackageReloadInternal::FExistingPackageReferences, PackageReloadInternal::FNewPackageReferences, ConstructorHelpers::FObjectFinder< T >, ConstructorHelpers::FObjectFinderOptional< T >, ConstructorHelpers::FClassFinder< T >, TGCObjectScopeGuard< ObjectType >, TGCObjectsScopeGuard< ObjectType >, FStreamableManager, FParticleSystemWorldManager, Audio::FSoundWavePCMLoader, FTextRenderComponentMIDCache, FChaosDerivedDataCookerRefHolder, FPendingStreamingLevelHolder, FSMInstanceElementIdMap, FRepLayout, FPreviewScene, FDebugCanvasDrawer, FDeferredCleanupSlateBrush, FSlateGameResources, FSubsystemCollection< TBaseType >, FSubsystemCollection< UAudioEngineSubsystem >, FViewport::FHitProxyMap, UE::Dataflow::FContextAssetStore, UE::Dataflow::TContextCacheElementUObject< T >, UE::Dataflow::TContextCacheElementUObjectArray< T >, UE::Dataflow::FContextCacheElementUStruct, UE::Dataflow::FContextCacheElementUStructArray, UE::Interchange::FImportResult, UE::Interchange::FImportAsyncHelper, FMassEntityManager, FMassProcessingPhaseManager, FPreLoadSettingsContainerBase, FLegacySlateFontInfoCache, FSlateInvalidationRoot, FStandaloneCompositeFont, FSlateDrawBuffer, FRetainerWidgetRenderingResources, SMeshWidget, FUMGDragDropOp, UE::UniversalObjectLocator::FRegistry, FDefaultWebBrowserAdapter, and FWebJSScripting.

GetReferencerName()

virtual FString FGCObject::GetReferencerName ( ) const

pure virtual

Overload this method to report a name for your referencer

Implemented in PackageReloadInternal::FExistingPackageReferences, PackageReloadInternal::FNewPackageReferences, FSlateDrawBuffer, Audio::FMixerDevice, Audio::FSoundSourceDecoder, FARSupportInterface, FAsyncPackage, ConstructorHelpers::FObjectFinder< T >, ConstructorHelpers::FObjectFinderOptional< T >, ConstructorHelpers::FClassFinder< T >, TGCObjectScopeGuard< ObjectType >, TGCObjectsScopeGuard< ObjectType >, FStreamableManager, FParticleSystemWorldManager, Audio::FSoundWavePCMLoader, FTextRenderComponentMIDCache, FChaosDerivedDataCookerRefHolder, FPendingStreamingLevelHolder, FSMInstanceElementIdMap, FRepLayout, FPreviewScene, FDebugCanvasDrawer, FDeferredCleanupSlateBrush, FSlateGameResources, FSubsystemCollection< TBaseType >, FSubsystemCollection< UAudioEngineSubsystem >, FViewport::FHitProxyMap, UE::Dataflow::FContextAssetStore, UE::Dataflow::TContextCacheElementUObject< T >, UE::Dataflow::TContextCacheElementUObjectArray< T >, UE::Dataflow::FContextCacheElementUStruct, UE::Dataflow::FContextCacheElementUStructArray, UE::Interchange::FImportResult, UE::Interchange::FImportAsyncHelper, FMassEntityManager, FMassProcessingPhaseManager, FPreLoadSettingsContainerBase, FLegacySlateFontInfoCache, FSlateInvalidationRoot, FStandaloneCompositeFont, FRetainerWidgetRenderingResources, SMeshWidget, FUMGDragDropOp, UE::UniversalObjectLocator::FRegistry, FDefaultWebBrowserAdapter, and FWebJSScripting.

GetReferencerPropertyName()

virtual bool FGCObject::GetReferencerPropertyName ( UObject *  Object, FString &  OutPropertyName  ) const

inlinevirtual

Overload this method to report how the specified object is referenced, if necessary

Reimplemented in FStreamableManager.

operator=() [1/2]

FGCObject & FGCObject::operator= ( const FGCObject &  )

inline

operator=() [2/2]

FGCObject & FGCObject::operator= ( FGCObject &&  )

inline

RegisterGCObject()

void FGCObject::RegisterGCObject

(

)

Register with GC, only needed if constructed with EFlags::RegisterLater or after unregistering

StaticInit()

UE_AUTORTFM_ALWAYS_OPEN void FGCObject::StaticInit ( )

static

Initializes the global object referencer and adds it to the root set.

UnregisterGCObject()

void FGCObject::UnregisterGCObject

(

)

Unregister ahead of destruction. Safe to call multiple times.

Member Data Documentation

GGCObjectReferencer

UGCObjectReferencer * FGCObject::GGCObjectReferencer = nullptr

static

The static object referencer object that is shared across all garbage collectible non-UObject objects.

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The documentation for this class was generated from the following files:

• Engine/Source/Runtime/CoreUObject/Public/UObject/GCObject.h
• Engine/Source/Runtime/CoreUObject/Private/Misc/GCObjectReferencer.cpp