.TH MPI_Ineighbor_alltoallw 3 "11/10/2017" " " "MPI"

.SH NAME

MPI_Ineighbor_alltoallw \-  Nonblocking version of MPI_Neighbor_alltoallw. 

.SH SYNOPSIS

.nf

int MPI_Ineighbor_alltoallw(const void *sendbuf, const int sendcounts[], const MPI_Aint sdispls[], const MPI_Datatype sendtypes[], void *recvbuf, const int recvcounts[], const MPI_Aint rdispls[], const MPI_Datatype recvtypes[], MPI_Comm comm, MPI_Request *request)

.fi

.SH INPUT PARAMETERS

.PD 0

.TP

.B sendbuf 

- starting address of the send buffer (choice)

.PD 1

.PD 0

.TP

.B sendcounts 

- non-negative integer array (of length outdegree) specifying the number of elements to send to each neighbor

.PD 1

.PD 0

.TP

.B sdispls 

- integer array (of length outdegree).  Entry j specifies the displacement in bytes (relative to sendbuf) from which to take the outgoing data destined for neighbor j (array of integers)

.PD 1

.PD 0

.TP

.B sendtypes 

- array of datatypes (of length outdegree).  Entry j specifies the type of data to send to neighbor j (array of handles)

.PD 1

.PD 0

.TP

.B recvcounts 

- non-negative integer array (of length indegree) specifying the number of elements that are received from each neighbor

.PD 1

.PD 0

.TP

.B rdispls 

- integer array (of length indegree).  Entry i specifies the displacement in bytes (relative to recvbuf) at which to place the incoming data from neighbor i (array of integers).

.PD 1

.PD 0

.TP

.B recvtypes 

- array of datatypes (of length indegree).  Entry i specifies the type of data received from neighbor i (array of handles).

.PD 1

.PD 0

.TP

.B comm 

- communicator with topology structure (handle)

.PD 1

.SH OUTPUT PARAMETERS

.PD 0

.TP

.B recvbuf 

- starting address of the receive buffer (choice)

.PD 1

.PD 0

.TP

.B request 

- communication request (handle)

.PD 1

.SH 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 

.I malloc

or other non-MPICH runtime routines that are themselves not interrupt-safe.

.SH NOTES FOR FORTRAN

All MPI routines in Fortran (except for 

.I MPI_WTIME

and 

.I MPI_WTICK

) have

an additional argument 

.I ierr

at the end of the argument list.  

.I 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

.I call

statement.

All MPI objects (e.g., 

.I MPI_Datatype

, 

.I MPI_Comm

) are of type 

.I INTEGER

in Fortran.

.SH ERRORS

All MPI routines (except 

.I MPI_Wtime

and 

.I 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 

.I MPI_Comm_set_errhandler

(for communicators),

.I MPI_File_set_errhandler

(for files), and 

.I MPI_Win_set_errhandler

(for

RMA windows).  The MPI-1 routine 

.I MPI_Errhandler_set

may be used but

its use is deprecated.  The predefined error handler

.I MPI_ERRORS_RETURN

may be used to cause error values to be returned.

Note that MPI does 

.B not

guarentee that an MPI program can continue past

an error; however, MPI implementations will attempt to continue whenever

possible.