gko::experimental::mpi::contiguous_type

Move-only RAII wrapper around a contiguous MPI_Datatype. The wrapper builds the datatype via MPI_Type_contiguous, commits it, and frees it on destruction.

gko::experimental::mpi::contiguous_type t{3, MPI_DOUBLE};
// t.get() is a committed MPI_Datatype representing 3 doubles

Used internally by the distributed kernels to ship multi-vector columns as a single typed message rather than as one MPI_Send per column.

class contiguous_type

A move-only wrapper for a contiguous MPI_Datatype.

The underlying MPI_Datatype is automatically created and committed when an object of this type is constructed, and freed when it is destructed.

Public Functions

inline contiguous_type(int count, MPI_Datatype old_type)

Constructs a wrapper for a contiguous MPI_Datatype.

Parameters:

• count – the number of old_type elements the new datatype contains.

• old_type – the MPI_Datatype that is contained.

inline contiguous_type()

Constructs empty wrapper with MPI_DATATYPE_NULL.

contiguous_type(const contiguous_type&) = delete

Disallow copying of wrapper type.

contiguous_type &operator=(const contiguous_type&) = delete

Disallow copying of wrapper type.

inline contiguous_type(contiguous_type &&other) noexcept

Move constructor, leaves other with MPI_DATATYPE_NULL.

Parameters:

other – to be moved from object.

inline contiguous_type &operator=(contiguous_type &&other) noexcept

Move assignment, leaves other with MPI_DATATYPE_NULL.

Parameters:

other – to be moved from object.

Returns:

this object.

inline ~contiguous_type()

Destructs object by freeing wrapped MPI_Datatype.

inline MPI_Datatype get() const

Access the underlying MPI_Datatype.

Returns:

the underlying MPI_Datatype.