Navigation API > API/Runtime > API/Runtime/MassEntity > API/Runtime/MassEntity/TMassExternalSubsystemTraits References Module MassEntity Header /Engine/Source/Runtime/MassEntity/Public/MassExternalSubsystemTraits.h Include #include "MassExternalSubsystemTraits.h" Syntax enum { ThreadSafeRead = false, ThreadSafeWrite = false, } Copy full snippetenum { ThreadSafeRead = false, ThreadSafeWrite = false, } Values Name Description ThreadSafeRead Note that we're not supplying a default value for this property to be able to statically catch code that tries to access given subsystem without including the appropriate headers. ThreadSafeWrite