.\" Man page generated from reStructuredText. . .TH "MPI_INEIGHBOR_ALLGATHER" "3" "Jul 22, 2024" "" "Open MPI" . .nr rst2man-indent-level 0 . .de1 rstReportMargin \\$1 \\n[an-margin] level \\n[rst2man-indent-level] level margin: \\n[rst2man-indent\\n[rst2man-indent-level]] - \\n[rst2man-indent0] \\n[rst2man-indent1] \\n[rst2man-indent2] .. .de1 INDENT .\" .rstReportMargin pre: . RS \\$1 . nr rst2man-indent\\n[rst2man-indent-level] \\n[an-margin] . nr rst2man-indent-level +1 .\" .rstReportMargin post: .. .de UNINDENT . RE .\" indent \\n[an-margin] .\" old: \\n[rst2man-indent\\n[rst2man-indent-level]] .nr rst2man-indent-level -1 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]] .in \\n[rst2man-indent\\n[rst2man-indent-level]]u .. .INDENT 0.0 .INDENT 3.5 .UNINDENT .UNINDENT .sp \fI\%MPI_Neighbor_allgather\fP, \fI\%MPI_Ineighbor_allgather\fP, \fI\%MPI_Neighbor_allgather\fP — Gathers and distributes data from and to all neighbors .SH SYNTAX .SS C Syntax .INDENT 0.0 .INDENT 3.5 .sp .nf .ft C #include int MPI_Neighbor_allgather(const void *sendbuf, int sendcount, MPI_Datatype sendtype, void *recvbuf, int recvcount, MPI_Datatype recvtype, MPI_Comm comm) int MPI_Ineighbor_allgather(const void *sendbuf, int sendcount, MPI_Datatype sendtype, void *recvbuf, int recvcount, MPI_Datatype recvtype, MPI_Comm comm, MPI_Request req) int MPI_Neighbor_allgather_init(const void *sendbuf, int sendcount, MPI_Datatype sendtype, void *recvbuf, int recvcount, MPI_Datatype recvtype, MPI_Comm comm, MPI_Infoinfo, MPI_Request req) .ft P .fi .UNINDENT .UNINDENT .SS Fortran Syntax .INDENT 0.0 .INDENT 3.5 .sp .nf .ft C USE MPI ! or the older form: INCLUDE \(aqmpif.h\(aq MPI_NEIGHBOR_ALLGATHER(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF, RECVCOUNT, RECVTYPE, COMM, IERROR) SENDBUF (*), RECVBUF (*) INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT, RECVTYPE, COMM, INTEGER IERROR MPI_INEIGHBOR_ALLGATHER(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF, RECVCOUNT, RECVTYPE, COMM, REQUEST, IERROR) SENDBUF (*), RECVBUF (*) INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT, RECVTYPE, COMM, INTEGER REQUEST, IERROR MPI_NEIGHBOR_ALLGATHER_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF, RECVCOUNT, RECVTYPE, COMM, INFO, IREQUEST, IERROR) SENDBUF (*), RECVBUF (*) INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT, RECVTYPE, COMM, INTEGER INFO, REQUEST, IERROR .ft P .fi .UNINDENT .UNINDENT .SS Fortran 2008 Syntax .INDENT 0.0 .INDENT 3.5 .sp .nf .ft C USE mpi_f08 MPI_Neighbor_allgather(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype, comm, ierror) TYPE(*), DIMENSION(..), INTENT(IN) :: sendbuf TYPE(*), DIMENSION(..) :: recvbuf INTEGER, INTENT(IN) :: sendcount, recvcount TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype TYPE(MPI_Comm), INTENT(IN) :: comm INTEGER, OPTIONAL, INTENT(OUT) :: ierror MPI_Ineighbor_allgather(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype, comm, request, ierror) TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf INTEGER, INTENT(IN) :: sendcount, recvcount TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype TYPE(MPI_Comm), INTENT(IN) :: comm TYPE(MPI_Request), INTENT(OUT) :: request INTEGER, OPTIONAL, INTENT(OUT) :: ierror MPI_Neighbor_allgather_init(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype, comm, info, request, ierror) TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf INTEGER, INTENT(IN) :: sendcount, recvcount TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype TYPE(MPI_Comm), INTENT(IN) :: comm TYPE(MPI_Info), INTENT(IN) :: info TYPE(MPI_Request), INTENT(OUT) :: request INTEGER, OPTIONAL, INTENT(OUT) :: ierror .ft P .fi .UNINDENT .UNINDENT .SH INPUT PARAMETERS .INDENT 0.0 .IP \(bu 2 \fBsendbuf\fP: Starting address of send buffer (choice). .IP \(bu 2 \fBsendcount\fP: Number of elements in send buffer (integer). .IP \(bu 2 \fBsendtype\fP: Datatype of send buffer elements (handle). .IP \(bu 2 \fBrecvbuf\fP: Starting address of recv buffer (choice). .IP \(bu 2 \fBrecvcount\fP: Number of elements received from any process (integer). .IP \(bu 2 \fBrecvtype\fP: Datatype of receive buffer elements (handle). .IP \(bu 2 \fBcomm\fP: Communicator (handle). .UNINDENT .SH OUTPUT PARAMETERS .INDENT 0.0 .IP \(bu 2 \fBrecvbuf\fP: Address of receive buffer (choice). .IP \(bu 2 \fBrequest\fP: Request (handle, non\-blocking only). .IP \(bu 2 \fBierror\fP: Fortran only: Error status (integer). .UNINDENT .SH DESCRIPTION .sp \fI\%MPI_Neighbor_allgather\fP is similar to \fI\%MPI_Allgather\fP, except that only the neighboring processes receive the result, instead of all processes. The neighbors and buffer layout is determined by the topology of \fIcomm\fP\&. .sp The type signature associated with sendcount, sendtype at a process must be equal to the type signature associated with recvcount, recvtype at any other process. .SH NEIGHBOR ORDERING .sp For a distributed graph topology, created with \fI\%MPI_Dist_graph_create\fP, the sequence of neighbors in the send and receive buffers at each process is defined as the sequence returned by \fI\%MPI_Dist_graph_neighbors\fP for destinations and sources, respectively. For a general graph topology, created with \fI\%MPI_Graph_create\fP, the order of neighbors in the send and receive buffers is defined as the sequence of neighbors as returned by \fI\%MPI_Graph_neighbors\fP\&. Note that general graph topologies should generally be replaced by the distributed graph topologies. .sp For a Cartesian topology, created with \fI\%MPI_Cart_create\fP, the sequence of neighbors in the send and receive buffers at each process is defined by order of the dimensions, first the neighbor in the negative direction and then in the positive direction with displacement 1. The numbers of sources and destinations in the communication routines are 2*ndims with ndims defined in \fI\%MPI_Cart_create\fP\&. If a neighbor does not exist, i.e., at the border of a Cartesian topology in the case of a non\-periodic virtual grid dimension (i.e., periods[…]==false), then this neighbor is defined to be \fBMPI_PROC_NULL\fP\&. .sp If a neighbor in any of the functions is \fBMPI_PROC_NULL\fP, then the neighborhood collective communication behaves like a point\-to\-point communication with \fBMPI_PROC_NULL\fP in this direction. That is, the buffer is still part of the sequence of neighbors but it is neither communicated nor updated. .SH NOTES .sp The MPI_IN_PLACE option for \fIsendbuf\fP is not meaningful for this operation. .SH ERRORS .sp Almost all MPI routines return an error value; C routines as the return result of the function and Fortran routines in the last argument. .sp Before the error value is returned, the current MPI error handler associated with the communication object (e.g., communicator, window, file) is called. If no communication object is associated with the MPI call, then the call is considered attached to MPI_COMM_SELF and will call the associated MPI error handler. When MPI_COMM_SELF is not initialized (i.e., before \fI\%MPI_Init\fP/\fI\%MPI_Init_thread\fP, after \fI\%MPI_Finalize\fP, or when using the Sessions Model exclusively) the error raises the initial error handler. The initial error handler can be changed by calling \fI\%MPI_Comm_set_errhandler\fP on MPI_COMM_SELF when using the World model, or the mpi_initial_errhandler CLI argument to mpiexec or info key to \fI\%MPI_Comm_spawn\fP/\fI\%MPI_Comm_spawn_multiple\fP\&. If no other appropriate error handler has been set, then the MPI_ERRORS_RETURN error handler is called for MPI I/O functions and the MPI_ERRORS_ABORT error handler is called for all other MPI functions. .sp Open MPI includes three predefined error handlers that can be used: .INDENT 0.0 .IP \(bu 2 \fBMPI_ERRORS_ARE_FATAL\fP Causes the program to abort all connected MPI processes. .IP \(bu 2 \fBMPI_ERRORS_ABORT\fP An error handler that can be invoked on a communicator, window, file, or session. When called on a communicator, it acts as if \fI\%MPI_Abort\fP was called on that communicator. If called on a window or file, acts as if \fI\%MPI_Abort\fP was called on a communicator containing the group of processes in the corresponding window or file. If called on a session, aborts only the local process. .IP \(bu 2 \fBMPI_ERRORS_RETURN\fP Returns an error code to the application. .UNINDENT .sp MPI applications can also implement their own error handlers by calling: .INDENT 0.0 .IP \(bu 2 \fI\%MPI_Comm_create_errhandler\fP then \fI\%MPI_Comm_set_errhandler\fP .IP \(bu 2 \fI\%MPI_File_create_errhandler\fP then \fI\%MPI_File_set_errhandler\fP .IP \(bu 2 \fI\%MPI_Session_create_errhandler\fP then \fI\%MPI_Session_set_errhandler\fP or at \fI\%MPI_Session_init\fP .IP \(bu 2 \fI\%MPI_Win_create_errhandler\fP then \fI\%MPI_Win_set_errhandler\fP .UNINDENT .sp Note that MPI does not guarantee that an MPI program can continue past an error. .sp See the \fI\%MPI man page\fP for a full list of \fI\%MPI error codes\fP\&. .sp See the Error Handling section of the MPI\-3.1 standard for more information. .sp \fBSEE ALSO:\fP .INDENT 0.0 .INDENT 3.5 .INDENT 0.0 .IP \(bu 2 \fI\%MPI_Neighbor_allgatherv\fP .IP \(bu 2 \fI\%MPI_Cart_create\fP .IP \(bu 2 MPI_Garph_create .IP \(bu 2 \fI\%MPI_Dist_graph_create\fP .IP \(bu 2 \fI\%MPI_Gather\fP .UNINDENT .UNINDENT .UNINDENT .SH COPYRIGHT 2003-2024, The Open MPI Community .\" Generated by docutils manpage writer. .