mpi

Class Intracomm

java.lang.Object

mpi.Comm

mpi.Intracomm

Direct Known Subclasses:

Cartcomm, Graphcomm

public class Intracomm
extends Comm

This class represents intracommunicators.

Field Summary

Fields inherited from class mpi.Comm

handle, MPI_COMM_NULL_VAL

Method Summary

Modifier and Type	Method and Description
void	allGather(java.lang.Object sendbuf, int sendcount, Datatype sendtype, java.lang.Object recvbuf, int recvcount, Datatype recvtype) Similar to Gather, but all processes receive the result.
void	allGatherv(java.lang.Object sendbuf, int sendcount, Datatype sendtype, java.lang.Object recvbuf, int[] recvcount, int[] displs, Datatype recvtype) Similar to Gatherv, but all processes receive the result.
void	allReduce(java.lang.Object sendbuf, java.lang.Object recvbuf, int count, Datatype datatype, Op op) Same as reduce except that the result appears in receive buffer of all process in the group.
void	allToAll(java.lang.Object sendbuf, int sendcount, Datatype sendtype, java.lang.Object recvbuf, int recvcount, Datatype recvtype) Extension of Allgather to the case where each process sends distinct data to each of the receivers.
void	allToAllv(java.lang.Object sendbuf, int[] sendcount, int[] sdispls, Datatype sendtype, java.lang.Object recvbuf, int[] recvcount, int[] rdispls, Datatype recvtype) Adds flexibility to Alltoall: location of data for send is specified by sdispls and location to place data on receive side is specified by rdispls.
void	barrier() A call to Barrier blocks the caller until all process in the group have called it.
void	bcast(java.lang.Object buf, int count, Datatype type, int root) Broadcast a message from the process with rank root to all processes of the group.
Intracomm	clone() Duplicate this communicator.
Intracomm	create(Group group) Create a new communicator.
Cartcomm	createCart(int[] dims, boolean[] periods, boolean reorder) Create a Cartesian topology communicator whose group is a subset of the group of this communicator.
Graphcomm	createGraph(int[] index, int[] edges, boolean reorder) Create a graph topology communicator whose group is a subset of the group of this communicator.
Intracomm	createGroup(Group group, int tag) Create a new intracommunicator for the given group.
void	gather(java.lang.Object sendbuf, int sendcount, Datatype sendtype, java.lang.Object recvbuf, int recvcount, Datatype recvtype, int root) Each process sends the contents of its send buffer to the root process.
void	gatherv(java.lang.Object sendbuf, int sendcount, Datatype sendtype, java.lang.Object recvbuf, int[] recvcount, int[] displs, Datatype recvtype, int root) Extends functionality of Gather by allowing varying counts of data from each process.
void	nativeGatherv(long commHandle, java.nio.Buffer sendbuf, int count, int datatype, java.nio.Buffer recvbuf, int[] recvcount, int recvtype, int[] displs, int root)
void	reduce(java.lang.Object sendbuf, java.lang.Object recvbuf, int count, Datatype datatype, Op op, int root) Combine elements in input buffer of each process using the reduce operation, and return the combined value in the output buffer of the root process.
void	reduceScatter(java.lang.Object sendbuf, java.lang.Object recvbuf, int[] recvcounts, Datatype datatype, Op op) Combine elements in input buffer of each process using the reduce operation, and scatter the combined values over the output buffers of the processes.
void	scan(java.lang.Object sendbuf, java.lang.Object recvbuf, int count, Datatype datatype, Op op) Perform a prefix reduction on data distributed across the group.
void	scatter(java.lang.Object sendbuf, int sendcount, Datatype sendtype, java.lang.Object recvbuf, int recvcount, Datatype recvtype, int root) Inverse of the operation Gather.
void	scatterv(java.lang.Object sendbuf, int[] sendcount, int[] displs, Datatype sendtype, java.lang.Object recvbuf, int recvcount, Datatype recvtype, int root) Inverse of the operation Gatherv.
Intracomm	split(int color, int key) Partition the group associated with this communicator and create a new communicator within each subgroup.

Methods inherited from class mpi.Comm

Abort, bSend, bSendInit, compare, create, createIntercomm, deleteAttr, free, getAttr, getGroup, getRank, getSize, getTopology, ibSend, iProbe, iRecv, irSend, iSend, isInter, isNull, isSend, pack, packSize, probe, recv, recvInit, rSend, rSendInit, send, sendInit, sendRecv, sendRecvReplace, spawn, spawnMultiple, sSend, sSendInit, unpack

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

split

public Intracomm split(int color,
                       int key)
                throws MPIException

Partition the group associated with this communicator and create a new communicator within each subgroup.

Parameters:

color - control of subset assignment.

key - control of rank assignment.

Returns:

new communicator. Java binding of the MPI operation MPI_COMM_SPLIT.

Throws:

MPIException - Points out that an MPI exception has occured.

clone

public Intracomm clone()
                throws MPIException

Duplicate this communicator.

Overrides:

clone in class Comm

Returns:

copy of this communicator. Java binding of the MPI operation MPI_COMM_DUP. The new communicator is ``congruent'' to the old one, but has a different context.

Throws:

MPIException - Points out that an MPI exception has occured.

create

public Intracomm create(Group group)
                 throws MPIException

Create a new communicator.

Parameters:

group - group which is a subset of the group of this communicator.

Returns:

new communicator. Java binding of the MPI operation MPI_COMM_CREATE.

Throws:

MPIException - Points out that an MPI exception has occured.

barrier

public void barrier()
             throws MPIException

A call to Barrier blocks the caller until all process in the group have called it. Java binding of the MPI operation MPI_BARRIER.

Throws:

MPIException

bcast

public void bcast(java.lang.Object buf,
                  int count,
                  Datatype type,
                  int root)
           throws MPIException

Broadcast a message from the process with rank root to all processes of the group.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.CHAR, MPI.SHORT, MPI.BOOLEAN, MPI.INT, MPI.LONG, MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

buf - buffer array.

count - number of items in buffer.

type - datatype of each item in buffer.

root - rank of broadcast root.

Java binding of the MPI operation MPI_BCAST.

Throws:

MPIException - Points out that an MPI exception has occured.

gather

public void gather(java.lang.Object sendbuf,
                   int sendcount,
                   Datatype sendtype,
                   java.lang.Object recvbuf,
                   int recvcount,
                   Datatype recvtype,
                   int root)
            throws MPIException

Each process sends the contents of its send buffer to the root process.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.CHAR, MPI.SHORT, MPI.BOOLEAN, MPI.INT, MPI.LONG, MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

sendcount - number of items to send.

sendtype - datatype of each item in send buffer.

recvbuf - receive buffer array.

recvcount - number of items to receive.

recvtype - datatype of each item in receive buffer.

root - rank of receiving process.

Java binding of the MPI operation MPI_GATHER.

Throws:

MPIException - Points out that an MPI exception has occured.

gatherv

public void gatherv(java.lang.Object sendbuf,
                    int sendcount,
                    Datatype sendtype,
                    java.lang.Object recvbuf,
                    int[] recvcount,
                    int[] displs,
                    Datatype recvtype,
                    int root)
             throws MPIException

Extends functionality of Gather by allowing varying counts of data from each process.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.CHAR MPI.SHORT, MPI.INT, MPI.LONG, MPI.BOOLEAN MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

sendcount - number of items to send.

sendtype - datatype of each item in send buffer.

recvbuf - receive buffer array.

recvcount - number of elements received from each process.

displs - displacements at which to place incoming data.

recvtype - datatype of each item in receive buffer.

root - rank of receiving process.

Java binding of the MPI operation MPI_GATHERV.

The sizes of arrays recvcount and displs should be the size of the group.

Entry i of displs specifies the displacement relative to element recvoffset of recvbuf at which to place incoming data.

Throws:

MPIException - Points out that an MPI exception has occured.

scatter

public void scatter(java.lang.Object sendbuf,
                    int sendcount,
                    Datatype sendtype,
                    java.lang.Object recvbuf,
                    int recvcount,
                    Datatype recvtype,
                    int root)
             throws MPIException

Inverse of the operation Gather.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.CHAR, MPI.SHORT, MPI.BOOLEAN, MPI.INT, MPI.LONG, MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

sendcount - number of items to send.

sendtype - datatype of each item in send buffer.

recvbuf - receive buffer array.

recvcount - number of items to receive.

recvtype - datatype of each item in receive buffer.

root - rank of sending process.

Java binding of the MPI operation MPI_SCATTER.

Throws:

MPIException - Points out that an MPI exception has occured.

scatterv

public void scatterv(java.lang.Object sendbuf,
                     int[] sendcount,
                     int[] displs,
                     Datatype sendtype,
                     java.lang.Object recvbuf,
                     int recvcount,
                     Datatype recvtype,
                     int root)
              throws MPIException

Inverse of the operation Gatherv.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.CHAR, MPI.SHORT, MPI.INT, MPI.LONG, MPI.BOOLEAN, MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

sendcount - number of items to send.

displs - displacements from which to take outgoing data.

sendtype - datatype of each item in send buffer.

recvbuf - receive buffer array.

recvcount - number of items to receive.

recvtype - datatype of each item in receive buffer.

root - rank of sending process.

Java binding of the MPI operation MPI_SCATTERV.

Throws:

MPIException - Points out that an MPI exception has occured.

allGather

public void allGather(java.lang.Object sendbuf,
                      int sendcount,
                      Datatype sendtype,
                      java.lang.Object recvbuf,
                      int recvcount,
                      Datatype recvtype)
               throws MPIException

Similar to Gather, but all processes receive the result.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.CHAR, MPI.SHORT, MPI.BOOLEAN, MPI.INT, MPI.LONG, MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

sendcount - number of items to send.

sendtype - datatype of each item in send buffer.

recvbuf - receive buffer array.

recvcount - number of items to receive.

recvtype - datatype of each item in receive buffer.

Java binding of the MPI operation MPI_ALLGATHER.

Throws:

MPIException - Points out that an MPI exception has occured.

allGatherv

public void allGatherv(java.lang.Object sendbuf,
                       int sendcount,
                       Datatype sendtype,
                       java.lang.Object recvbuf,
                       int[] recvcount,
                       int[] displs,
                       Datatype recvtype)
                throws MPIException

Similar to Gatherv, but all processes receive the result.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.CHAR, MPI.SHORT, MPI.INT, MPI.LONG, MPI.BOOLEAN, MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

sendcount - number of items to send.

sendtype - datatype of each item in send buffer.

recvbuf - receive buffer array.

recvcount - number of items to receive.

displs - displacements at which to place incoming data.

recvtype - datatype of each item in receive buffer.

Java binding of the MPI operation MPI_ALLGATHERV.

Throws:

MPIException - Points out that an MPI exception has occured.

allToAll

public void allToAll(java.lang.Object sendbuf,
                     int sendcount,
                     Datatype sendtype,
                     java.lang.Object recvbuf,
                     int recvcount,
                     Datatype recvtype)
              throws MPIException

Extension of Allgather to the case where each process sends distinct data to each of the receivers.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.BOOLEAN MPI.SHORT, MPI.INT, MPI.LONG, MPI.CHAR MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

sendcount - number of items to send.

sendtype - datatype of each item in send buffer.

recvbuf - receive buffer array.

recvcount - number of items to receive.

recvtype - datatype to receive buffer items.

Java binding of the MPI operation MPI_ALLTOALL.

Throws:

MPIException - Points out that an MPI exception has occured.

allToAllv

public void allToAllv(java.lang.Object sendbuf,
                      int[] sendcount,
                      int[] sdispls,
                      Datatype sendtype,
                      java.lang.Object recvbuf,
                      int[] recvcount,
                      int[] rdispls,
                      Datatype recvtype)
               throws MPIException

Adds flexibility to Alltoall: location of data for send is specified by sdispls and location to place data on receive side is specified by rdispls.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.CHAR MPI.SHORT, MPI.INT, MPI.LONG, MPI.BOOLEAN MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

sendcount - number of items to send.

sdispls - displacements from which to take outgoing data.

sendtype - datatype of each item in send buffer.

recvbuf - receive buffer array.

recvcount - number of items to receive.

rdispls - displacements at which to place incoming data.

recvtype - datatype to receive buffer items.

Java binding of the MPI operation MPI_ALLTOALLV.

Throws:

MPIException - Points out that an MPI exception has occured.

reduce

public void reduce(java.lang.Object sendbuf,
                   java.lang.Object recvbuf,
                   int count,
                   Datatype datatype,
                   Op op,
                   int root)
            throws MPIException

Combine elements in input buffer of each process using the reduce operation, and return the combined value in the output buffer of the root process.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.BOOLEAN, MPI.SHORT, MPI.INT, MPI.LONG, MPI.CHAR MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

recvbuf - receive buffer array.

count - number of items in send buffer.

datatype - datatype of each item in send buffer.

op - reduce operation.

root - rank of root process.

Java binding of the MPI operation MPI_REDUCE.

The predefined operations are available in Java as MPI.MAX, MPI.MIN, MPI.SUM, MPI.PROD, MPI.LAND, MPI.BAND, MPI.LOR, MPI.BOR, MPI.LXOR, MPI.BXOR, MPI.MINLOC and MPI.MAXLOC.

Throws:

MPIException - Points out that an MPI exception has occured.

allReduce

public void allReduce(java.lang.Object sendbuf,
                      java.lang.Object recvbuf,
                      int count,
                      Datatype datatype,
                      Op op)
               throws MPIException

Same as reduce except that the result appears in receive buffer of all process in the group.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.BYTE, MPI.BOOLEAN, MPI.SHORT, MPI.INT, MPI.LONG, MPI.CHAR MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

recvbuf - receive buffer array.

count - number of items in send buffer.

datatype - datatype of each item in send buffer.

op - reduce operation.

Java binding of the MPI operation MPI_ALLREDUCE.

Throws:

MPIException - Points out that an MPI exception has occured.

reduceScatter

public void reduceScatter(java.lang.Object sendbuf,
                          java.lang.Object recvbuf,
                          int[] recvcounts,
                          Datatype datatype,
                          Op op)
                   throws MPIException

Combine elements in input buffer of each process using the reduce operation, and scatter the combined values over the output buffers of the processes.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.SHORT, MPI.INT, MPI.BOOLEAN, MPI.CHAR, MPI.BYTE, MPI.LONG, MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

recvbuf - receive buffer array.

recvcounts - numbers of result elements distributed to each process.

datatype - datatype of each item in send buffer.

op - reduce operation.

Java binding of the MPI operation MPI_REDUCE_SCATTER.

Throws:

MPIException - Points out that an MPI exception has occured.

scan

public void scan(java.lang.Object sendbuf,
                 java.lang.Object recvbuf,
                 int count,
                 Datatype datatype,
                 Op op)
          throws MPIException

Perform a prefix reduction on data distributed across the group.

The method supports communication of both ByteBuffers and Java arrays. For arrays, the datatypes MPI.SHORT, MPI.INT, MPI.BOOLEAN, MPI.CHAR, MPI.BYTE, MPI.LONG, MPI.FLOAT, and MPI.DOUBLE are supported. For ByteBuffers, the datatypes we currently support are MPI.BYTE.

Parameters:

sendbuf - send buffer array.

recvbuf - receive buffer array.

count - number of items in input buffer.

datatype - datatype of each item in send buffer.

op - reduce operations.

Java binding of the MPI operation MPI_SCAN.

Throws:

MPIException - Points out that an MPI exception has occured.

createCart

public Cartcomm createCart(int[] dims,
                           boolean[] periods,
                           boolean reorder)
                    throws MPIException

Create a Cartesian topology communicator whose group is a subset of the group of this communicator.

Not Implemented in the current release

.

Parameters:

dims - the number of processes in each dimension.

periods - true if grid is periodic in each dimension, otherwise false.

reorder - true if ranking may be reordered, false, false if not.

Returns:

new Cartesian topology communicator.

Java binding of the MPI operation MPI_CART_CREATE.

The number of dimensions of the Cartesian grid is taken to be the size of the dims argument. The array periods must be the same size.

Throws:

MPIException - Points out that an MPI exception has occured.

createGraph

public Graphcomm createGraph(int[] index,
                             int[] edges,
                             boolean reorder)
                      throws MPIException

Create a graph topology communicator whose group is a subset of the group of this communicator.

Not Implemented in the current release

.

Parameters:

index - node degrees.

edges - graph edges.

reorder - true if ranking may be reordered, false, false if not.

Returns:

new graph topology communicator.

Java binding of the MPI operation MPI_GRAPH_CREATE.

The number of nodes in the graph, nnodes, is taken to be size of the index argument. The size of array edges must be index [nnodes - 1]}.

Throws:

MPIException

createGroup

public Intracomm createGroup(Group group,
                             int tag)
                      throws MPIException

Create a new intracommunicator for the given group.

Parameters:

group - group which is a subset of the group of this communicator

tag - an integer tag

Java binding of the MPI operation MPI_COMM_CREATE_GROUP.

Returns:

new communicator

Throws:

MPIException - Points out that an MPI exception has occured.

nativeGatherv

public void nativeGatherv(long commHandle,
                          java.nio.Buffer sendbuf,
                          int count,
                          int datatype,
                          java.nio.Buffer recvbuf,
                          int[] recvcount,
                          int recvtype,
                          int[] displs,
                          int root)