MPI_Get_count

Gets the number of "top level" elements

Synopsis

#include "mpi.h"
int MPI_Get_count( status, datatype, count )
MPI_Status   *status;
MPI_Datatype datatype;
int          *count;

Input Parameters

status return status of receive operation (Status)
datatype datatype of each receive buffer element (handle)

Output Parameter

count
number of received elements (integer) Notes: If the size of the datatype is zero, this routine will return a count of zero. If the amount of data in status is not an exact multiple of the size of datatype (so that count would not be integral), a count of MPI_UNDEFINED is returned instead.

Notes for Fortran

All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK) havean additional argument ierr at the end of the argument list. ierris an integer and has the same meaning as the return value of the routinein C. In Fortran, MPI routines are subroutines, and are invoked with thecall statement.

All MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGERin Fortran.

Errors

All MPI routines (except MPI_Wtime and MPI_Wtick) return an error value; C routines as the value of the function and Fortran routines in the lastargument. Before the value is returned, the current MPI error handler iscalled. By default, this error handler aborts the MPI job. The error handlermay be changed with MPI_Errhandler_set; the predefined error handlerMPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarentee that an MPI program can continue pastan error.

MPI_SUCCESS
No error; MPI routine completed successfully.
MPI_ERR_TYPE
Invalid datatype argument. May be an uncommitted MPI_Datatype (see MPI_Type_commit).

Location:getcount.c