MPI_Ialltoallv(3) MPI MPI_Ialltoallv(3)
NAME
MPI_Ialltoallv - Sends data from all to all processes in a nonblocking
way; each process may send a different amount of data and provide
displacements for the input and output data.
SYNOPSIS
int MPI_Ialltoallv(const void *sendbuf, const int sendcounts[],
const int sdispls[], MPI_Datatype sendtype, void *recvbuf,
const int recvcounts[], const int rdispls[],
MPI_Datatype recvtype, MPI_Comm comm, MPI_Request *request)
int MPI_Ialltoallv_c(const void *sendbuf, const MPI_Count sendcounts[],
const MPI_Aint sdispls[], MPI_Datatype sendtype,
void *recvbuf, const MPI_Count recvcounts[],
const MPI_Aint rdispls[], MPI_Datatype recvtype,
MPI_Comm comm, MPI_Request *request)
INPUT PARAMETERS
sendbuf
- starting address of send buffer (choice)
sendcounts
- non-negative integer array (of length group size) specifying the
number of elements to send to each rank (non-negative integer)
sdispls
- integer array (of length group size). Entry j specifies the
displacement (relative to sendbuf) from which to take the outgoing
data destined for process j (integer)
sendtype
- data type of send buffer elements (handle)
recvcounts
- non-negative integer array (of length group size) specifying the
number of elements that can be received from each rank (non-
negative integer)
rdispls
- integer array (of length group size). Entry i specifies the
displacement (relative to recvbuf) at which to place the incoming
data from process i (integer)
recvtype
- data type of receive buffer elements (handle)
comm - communicator (handle)
OUTPUT PARAMETERS
recvbuf
- address of receive buffer (choice)
request
- communication request (handle)
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.
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_BUFFER
- Invalid buffer pointer. Usually a null buffer where one is not
valid.
MPI_ERR_COMM
- Invalid communicator. A common error is to use a null
communicator in a call (not even allowed in MPI_Comm_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.
1/27/2023 MPI_Ialltoallv(3)
mpi 4.1 - Generated Sat Jan 28 08:24:57 CST 2023