This class was used indirectly by the old `ArrayHandle`, through
`ArrayHandleTransfer`, to move data to and from a device. This
functionality has been replaced in the new `ArrayHandle`s through the
`Buffer` class (which can be compiled into libraries rather than make
every translation unit compile their own template).
This commit removes `ArrayManagerExecution` and all the implementations
that the device adapters were required to make. None of this code was in
any use anymore.
`ArrayTransfer` is used with the old `ArrayHandle` style to move data
between host and device. The new version of `ArrayHandle` does not use
`ArrayTransfer` at all because this functionality is wrapped in `Buffer`
(where it can exist in a precompiled library).
Once all the old `ArrayHandle` classes are gone, this class will be
removed completely. Although all the remaining `ArrayHandle` classes
provide their own versions of `ArrayTransfer`, they still need the
prototype to be defined to specialize. Thus, the guts of the default
`ArrayTransfer` are removed and replaced with a compile error if you try
to compile it.
The old version of ExecutionObject (that only takes a device) is still
supported, but you will get a deprecated warning if that is what is
defined.
Supporing this also included sending vtkm::cont::Token through the
vtkm::cont::arg::Transport mechanism, which was a change that propogated
through a lot of code.
Sandia National Laboratories recently changed management from the
Sandia Corporation to the National Technology & Engineering Solutions
of Sandia, LLC (NTESS). The copyright statements need to be updated
accordingly.
Change the VTKM_CONT_EXPORT to VTKM_CONT. (Likewise for EXEC and
EXEC_CONT.) Remove the inline from these macros so that they can be
applied to everything, including implementations in a library.
Because inline is not declared in these modifies, you have to add the
keyword to functions and methods where the implementation is not inlined
in the class.
ArrayHandles in DAX have a CopyInto function which allows the user to copy an array handle's data into a compatible STL type iterator. Originally this was fairly straight forward to implement since array handles in DAX are templated on the DeviceAdapterTag. In contrast, VTKm array handles use a polymorphic ArrayHandleExecutionManager under the hood allowing a single array handle to interface with multiple devices at runtime. To achieve this virtual functions are used. This makes implementing the CopyInto function difficult since it is templated on the IteratorType and virtual functions cannot be templated.
To work around this, I've implemented a concrete templated CopyInto function in the class derived from ArrayHandleExecutionManagerBase. In the ArrayHandle class, CopyInto dynamically casts the base class into the derived class, then calls the CopyInto function defined in the derived class.
The drawback to this approach is that, should the user define their own class that inherits from ArrayHandleExectionManagerBase, they are not forced to implement the CopyInto function, unlike the other virtual functions.
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.
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.
It was originally put there to support CopyInto in ArrayHandle, but that
has already been removed. It really only makes sense for trivial
examples and testing code, and it sometimes causes complications with
coding.
We made this change a while ago to help with completion in IDEs.
(Completion was matching a bunch of wrapper macros that were almost
never used anywhere.) Most of the changes are in comments, but there are
a few bad macro definitions.
