Concepts

Kokkos Comm-specific concepts

template<typename T>
concept CommunicationSpace

Specifies that a type T is a Kokkos Comm communication backend.

Constraints for implementing the ``CommunicationSpace`` concept

type T::communication_space

type T::communicator_type

type T::request_type

type T::datatype_type

type T::reduction_op_type

type T::size_type

type T::rank_type

Types implementing the CommunicationSpace concept

class MpiSpace

using communication_space = MpiSpace

using communicator_type = MPI_Comm

using request_type = MPI_Request

using datatype_type = MPI_Datatype

using reduction_op_type = MPI_Op

using size_type = int

using rank_type = int

class Experimental::NcclSpace

using communication_space = NcclSpace

using communicator_type = ncclComm_t

using request_type = cudaEvent_t

using datatype_type = ncclDataType_t

using reduction_op_type = ncclRedOp_t

using size_type = int

using rank_type = int

template<typename T>
concept ReductionOperator

Specifies that a type T is a Kokkos Comm reduction operator.

Types implementing the ReductionOperator concept

class BAnd

The bitwise AND operator (&).

class BOr

The bitwise OR operator (|).

class BXor

The bitwise XOR (exclusive OR) operator (^).

class LAnd

The logical AND operator (&&).

class LOr

The logical OR operator (||).

class LXor

The logical XOR (exclusive OR) operator.

class Max

The MAXIMUM operator.

class MaxLoc

The MAXIMUM with location (index) operator.

class Min

The MINIMUM operator.

class MinLoc

The MINIMUM with location (index) operator.

class Sum

The SUM operator.

class Prod

The PRODUCT operator.

class Average

The AVERAGE operator.

Kokkos interoperability concepts

template<typename T>
concept KokkosView

Specifies that a type T is a Kokkos::View object.

This concept accepts both mutable views, such as Kokkos::View<T*>, and views with a constant value type, such as Kokkos::View<const T*>.

Kokkos Comm uses this concept for view arguments that are not written by the communication operation, such as send buffers. The view may still be mutable for other uses, such as Kokkos kernels.

template<typename T>
concept MutKokkosView

Specifies that a type T is a mutable Kokkos::View object, such as Kokkos::View<T*>.

Kokkos Comm uses this concept for view arguments that may be written by a communication operation, such as receive buffers and in-place collective buffers.

template<typename T>
concept KokkosExecutionSpace

Specifies that a type T is a Kokkos::ExecutionSpace.

template<typename T>
concept KokkosMemorySpace

Specifies that a type T is a Kokkos::MemorySpace.