MPI_Get_accumulate function

Performs atomic read-modify-write and returns the data before the accumulate operation.

Syntax

int MPIAPI MPI_Get_accumulate(
  _In_  void         *origin_addr,
        int          origin_count,
        MPI_Datatype origin_datatype,
  _Out_ void         *result_addr,
        int          result_count,
        MPI_Datatype result_datatype,
        int          target_rank,
        MPI_Aint     target_disp,
        int          target_count,
        MPI_Datatype datatype,
        MPI_Op       op,
        MPI_Win      win
);

Parameters

• origin_addr [in]
  initial address of buffer

• origin_count
  number of entries in buffer

• origin_datatype
  datatype of each buffer entry

• result_addr [out]
  initial address of result buffer

• result_count
  number of entries in result buffer

• result_datatype
  datatype of each entry in result buffer

• target_rank
  rank of target

• target_disp
  displacement from start of window to beginning of target buffer

• target_count
  number of entries in target buffer

• datatype
  datatype of each entry in target buffer

• op
  predefined reduce operation

• win
  window object

Return value

Returns MPI_SUCCESS on success. Otherwise, the return value is an error code.

In Fortran, the return value is stored in the IERROR parameter.

Fortran

    MPI_GET_ACCUMULATE(ORIGIN_ADDR, ORIGIN_COUNT, ORIGIN_DATATYPE, RESULT_ADDR, RESULT_COUNT, RESULT_DATATYPE,
                TARGET_RANK, TARGET_DISP, TARGET_COUNT, TARGET_DATATYPE, OP, WIN, IERROR)
        <type> ORIGIN_ADDR(*), RESULT_ADDR(*)
        INTEGER(KIND=MPI_ADDRESS_KIND) TARGET_DISP
        INTEGER ORIGIN_COUNT, ORIGIN_DATATYPE, RESULT_COUNT, RESULT_DATATYPE, TARGET_RANK, TARGET_COUNT,
        TARGET_DATATYPE, OP, WIN, IERROR

Remarks

Accumulate origin_count elements of type origin_datatype from the origin buffer (origin_addr) to the buffer at offset target_disp, in the target window specified by target_rank and win, using the operation op and return in the result buffer result_addr the content of the target buffer before the accumulation, specified by target_disp, target_count, and target_datatype. The data transferred from origin to target must fit, without truncation, in the target buffer. Likewise, the data copied from target to origin must fit, without truncation, in the result buffer.

The origin and result buffers (origin_addr and result_addr) must be disjoint. Each datatype argument must be a predefined datatype or a derived datatype where all basic components are of the same predefined datatype. All datatype arguments must be constructed from the same predefined datatype. The operation op applies to elements of that predefined type. target_datatype must not specify overlapping entries, and the target buffer must fit in the target window or in attached memory in a dynamic window. The operation is executed atomically for each basic datatype.

Requirements

See also

MPI One-Sided Communications Functions