Previously ArrayTransfer and ArrayManagerExecution received a reference
to a Storage class in their constructor and held the reference as an
ivar. In retrospect, this is just asking for trouble. First, it is way
too easy to pass by value when you mean to pass by reference. Second, if
there ever is a bug where the Storage goes out of scope before the
classes holding a reference, it is that much harder to debug.
This includes changing methods like LoadDataForInput to PrepareForInput.
It also changed the interface a bit to save a reference to the storage
object. (Maybe it would be better to save a pointer?) These changes also
extend up to the ArrayManagerExecution class, so it can effect device
adapter implementations.
This API change effects both ArrayTransfer and ArrayManagerExecution.
This is in preparation for a future change to make the API more
consistent with ArrayHandle.
The UserPortal in ArrayHandle was used to copy a pointer the user
created into an ArrayHandle to use in VTK-m algorithms. However, this is
only really valid for a basic storage, so the functionality has been
moved there, and you have to construct an ArrayHandle with a storage
instead of an array portal.
After a talk with Robert Maynard, we decided to change the name
ArrayContainerControl to Storage. There are several reasons for this
change.
1. The name ArrayContainerControl is unwieldy. It is long, hard for
humans to parse, and makes for long lines and wraparound. It is also
hard to distinguish from other names like ArrayHandleFoo and
ArrayExecutionManager.
2. The word container is getting overloaded. For example, there is a
SimplePolymorphicContainer. Container is being used for an object that
literally acts like a container for data. This class really manages
data.
3. The data does not necessarily have to be on the control side.
Implicit containers store the data nowhere. Derivative containers might
have all the real data on the execution side. It is possible in the
future to have storage on the execution environment instead of the
control (think interfacing with a simulator on the GPU).
Storage is not a perfect word (what does implicit storage really mean?),
but its the best English word we came up with.
