MPI_Type_hindexed(3) MPI MPI_Type_hindexed(3)
NAME
MPI_Type_hindexed - Creates an indexed datatype with offsets in bytes
SYNOPSIS
int MPI_Type_hindexed(int count, int array_of_blocklengths[],
MPI_Aint array_of_displacements[], MPI_Datatype oldtype,
MPI_Datatype *newtype)
INPUT PARAMETERS
count - number of blocks -- also number of entries in
array_of_displacements and array_of_blocklengths (non-negative
integer)
array_of_blocklengths
- number of elements in each block (non-negative integer)
array_of_displacements
- byte displacement of each block (integer)
oldtype
- old datatype (handle)
OUTPUT PARAMETERS
newtype
- new datatype (handle)
REMOVED FUNCTION
The current MPI standard defines this routine as removed. The user
should use the replacement routine. The replacement for this routine
is MPI_Type_create_hindexed .
THREAD AND INTERRUPT SAFETY
This routine is thread-safe. This means that this routine may be
safely used by multiple threads without the need for any user-provided
thread locks. However, the routine is not interrupt safe. Typically,
this is due to the use of memory allocation routines such as malloc or
other non-MPICH runtime routines that are themselves not interrupt-
safe.
NOTES FOR FORTRAN
All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
an additional argument ierr at the end of the argument list. ierr is
an integer and has the same meaning as the return value of the routine
in C. In Fortran, MPI routines are subroutines, and are invoked with
the call statement.
All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
Fortran. The array_of_displacements are displacements, and are based
on a zero origin. A common error is to do something like to following
integer a(100)
integer array_of_blocklengths(10), array_of_displacements(10)
do i=1,10
array_of_blocklengths(i) = 1
10 array_of_displacements(i) = (1 + (i-1)*10) * sizeofint
call MPI_TYPE_HINDEXED(10,array_of_blocklengths,array_of_displacements,MPI_INTEGER,newtype,ierr)
call MPI_TYPE_COMMIT(newtype,ierr)
call MPI_SEND(a,1,newtype,...)
expecting this to send "a(1),a(11),..." because the
array_of_displacements have values "1,11,...". Because these are
displacements from the beginning of "a", it actually sends
"a(1+1),a(1+11),...".
If you wish to consider the displacements as array_of_displacements
into a Fortran array, consider declaring the Fortran array with a zero
origin
integer a(0:99)
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 last argument. Before the value is returned, the current MPI error
handler is called. By default, this error handler aborts the MPI job.
The error handler may be changed with MPI_Comm_set_errhandler (for
communicators), MPI_File_set_errhandler (for files), and
MPI_Win_set_errhandler (for RMA windows). The MPI-1 routine
MPI_Errhandler_set may be used but its use is deprecated. The
predefined error handler MPI_ERRORS_RETURN may be used to cause error
values to be returned. Note that MPI does not guarantee that an MPI
program can continue past an error; however, MPI implementations will
attempt to continue whenever possible.
MPI_SUCCESS
- No error; MPI routine completed successfully.
MPI_ERR_ARG
- Invalid argument. Some argument is invalid and is not
identified by a specific error class (e.g., MPI_ERR_RANK ).
MPI_ERR_COUNT
- Invalid count argument. Count arguments must be non-negative;
a count of zero is often valid.
MPI_ERR_TYPE
- Invalid datatype argument. Additionally, this error can occur
if an uncommitted MPI_Datatype (see MPI_Type_commit ) is used in
a communication call.
MPI_ERR_OTHER
- Other error; use MPI_Error_string to get more information
about this error code.
2/3/2025 MPI_Type_hindexed(3)
mpi 4.3.0 - Generated Tue Mar 4 14:21:50 CST 2025