Now that we have the functions in `vtkm/Atomic.h`, we can deprecate (and
eventually remove) the more cumbersome classes `AtomicInterfaceControl`
and `AtomicInterfaceExecution`.
Also reversed the order of the `expected` and `desired` parameters of
`vtkm::AtomicCompareAndSwap`. I think the former order makes more sense
and matches more other implementations (such as `std::atomic` and the
GCC `__atomic` built ins). However, there are still some non-deprecated
classes with similar methods that cannot easily be switched. Thus, it's
better to be inconsistent with most other libraries and consistent with
ourself than to be inconsitent with ourself.
Now that we have atomic free functions (e.g. `vtkm::AtomicAdd()`), we no
longer need special implementations for control and each execution
device. (Well, technically we do have special implementations for each,
but they are handled with compiler directives in the free functions.)
Convert the old atomic interface classes (`AtomicInterfaceControl` and
`AtomicInterfaceExecution`) to use the new atomic free functions. This
will allow us to test the new atomic functions everywhere that atomics
are used in VTK-m.
Once verified, we can deprecate the old atomic interface classes.
The buffer class encapsulates the movement of raw C arrays between
host and devices.
The `Buffer` class itself is not associated with any device. Instead,
`Buffer` is used in conjunction with a new templated class named
`DeviceAdapterMemoryManager` that can allocate data on a given
device and transfer data as necessary. `DeviceAdapterMemoryManager`
will eventually replace the more complicated device adapter classes
that manage data on a device.
The code in `DeviceAdapterMemoryManager` is actually enclosed in
virtual methods. This allows us to limit the number of classes that
need to be compiled for a device. Rather, the implementation of
`DeviceAdapterMemoryManager` is compiled once with whatever compiler
is necessary, and then the `RuntimeDeviceInformation` is used to
get the correct object instance.
As the RuntimeDeviceTracker is a per thread construct we now make
it explicit that you can only get a reference to the per-thread
version and can't copy it.
BitFields are:
- Stored in memory using a contiguous buffer of bits.
- Accessible via portals, a la ArrayHandle.
- Portals operate on individual bits or words.
- Operations may be atomic for safe use from concurrent kernels.
The new BitFieldToUnorderedSet device algorithm produces an ArrayHandle
containing the indices of all set bits, in no particular order.
The new AtomicInterface classes provide an abstraction into bitwise
atomic operations across control and execution environments and are used
to implement the BitPortals.
`vtkm::cont::testing` now initializes with logging enabled and support
for device being passed on the command line, `vtkm::testing` only
enables logging.
Previously ArrayHandleBasicImpl had no support for OpenMP since
we forgot to update the implementation. This version will
work when adding new devices without any changes.
The previous implementation of DeviceAdapterRuntimeDetector caused
multiple differing definitions of the same class to exist and
was causing the runtime device tracker to report CUDA as disabled
when it actually was enabled.
The ODR was caused by having a default implementation for
DeviceAdapterRuntimeDetector and a specific specialization for
CUDA. If a library had both CUDA and C++ sources it would pick up
both implementations and would have undefined behavior. In general
it would think the CUDA backend was disabled.
To avoid this kind of situation in the future I have reworked VTK-m
so that each device adapter must implement DeviceAdapterRuntimeDetector
for that device.
By hard coding the PrepareForDevice to know about all the different VTK-m
devices, we can have a single base class do the execution allocation, and not
have that logic repeated in each child class.
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.
The old templated array transfer mechanism generated a lot of code
that ended up doing a simple, type-agnostic memcpy for most devices.
This patch specialized array handles for basic storage and uses a
fast-path array transfer implementation. This reduces the size of the
vtkm_cont library by 27% on gcc (from 6.2MB to 4.5MB).
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.
Previously each device adapter only had a unique string name. This was
not the best when it came to developing data structures to track the status
of a given device at runtime.
This adds in a unique numeric identifier to each device adapter. This will
allow classes to easily create bitmasks / lookup tables for the validity of
devices.
Previously it was really hard to verify if a device adapter was valid. Since
you would have to check for the existence of the tag. Now the tag always
exists, but instead you query the traits of the DeviceAdapter to see if
it is a valid adapter.
This makes compiling with multiple backends alot easier.
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.
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.
