Previously, when a ReadPortal or a WritePortal was returned from an
ArrayHandle, it had wrapped in it a Token that was attached to the
ArrayHandle. This Token would prevent other reads and writes from the
ArrayHandle.
This added safety in the form of making sure that the ArrayPortal was
always valid. Unfortunately, it also made deadlocks very easy. They
happened when an ArrayPortal did not leave scope immediately after use
(which is not all that uncommon).
Now, the ArrayPortal no longer locks up the ArrayHandle. Instead, when
an access happens on the ArrayPortal, it checks to make sure that
nothing has happened to the data being accessed. If it has, a fatal
error is reported to the log.
To get a portal to access ArrayHandle values in the control
environment, you now use the ReadPortal and WritePortal methods.
The portals returned are wrapped in an ArrayPortalToken object
so that the data between the portal and the ArrayHandle are
guaranteed to be consistent.
Marked the old versions of PrepareFor* that do not use tokens as
deprecated and moved all of the code to use the new versions that
require a token. This makes the scope of the execution object more
explicit so that it will be kept while in use and can potentially be
reclaimed afterward.
When a single `ArrayHandle` is given to multiple arguments of a worklet
dispatch, the `PrepareFor*` methods will be called multiple times with
the same token. If one of them is a `PrepareForInPlace` or
`PrepareForOutput`, then the two requests will deadlock. To prevent
this, allow the `PrepareFor*` to happen if the same token was used
previously.
Duplicated the new versions of PrepareFor* methods from the basic
ArrayHandle that take a token in addition to the other arguments. The
ArrayHandle attaches itself to the token and will not allow operaitons
that make the returned portal invalid until the token goes out of scope.
Later the old versions will be deprecated.
Added new versions of PrepareFor* methods that take a token in addition
to the other arguments. The ArrayHandle attaches itself to the token and
will not allow operations that make the returned portal invalid until
the token goes out of scope.
Later the old versions will be deprecated.
This adds an ExecutionSignature tag named Device that passes the
DeviceAdapterTag as an argument to the worklet's operator(). This allows
worklets to specialize their code based on the device.
Previously memory that was allocated outside of VTK-m was impossible to transfer to
VTK-m as we didn't know how to free it. By extending the ArrayHandle constructors
to support a Storage object that is being moved, we can clearly express that
the ArrayHandle now owns memory it didn't allocate.
Here is an example of how this is done:
```cpp
T* buffer = new T[100];
auto user_free_function = [](void* ptr) { delete[] static_cast<T*>(ptr); };
vtkm::cont::internal::Storage<T, vtkm::cont::StorageTagBasic>
storage(buffer, 100, user_free_function);
vtkm::cont::ArrayHandle<T> arrayHandle(std::move(storage));
```
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.
In generic code, it's a pain to use the equality operators since they
requires the ValueType and Storage to match, else the operator is undefined.
This commit adds operators for such comparisons, as well as a unit test.
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).
