npRmpi (version 0.60-20)

mpi.sendrecv: MPI_Sendrecv and MPI_Sendrecv_replace APIs

Description

mpi.sendrecv and mpi.sendrecv.replace execute blocking send and receive operations. Both of them combine the sending of one message to a destination and the receiving of another message from a source in one call. The source and destination are possibly the same. The send buffer and receive buffer are disjoint for mpi.sendrecv, while the buffers are not disjoint for mpi.sendrecv.replace.

Usage

mpi.sendrecv(senddata, sendtype, dest, sendtag, recvdata, recvtype, 
source, recvtag, comm = 1, status = 0)
mpi.sendrecv.replace(x, type, dest, sendtag, source, recvtag, 
comm = 1, status = 0)

Value

Returns the int, double or char vector sent from the send buffers.

Arguments

x

data to be sent or recieved. Must be the same type for source and destination.

senddata

data to be sent. May have different datatypes and lengths

recvdata

data to be recieved. May have different datatypes and lengths

type

type of the data to be sent or recieved. 1 for integer, 2 for double, and 3 for character. Others are not supported.

sendtype

type of the data to be sent. 1 for integer, 2 for double, and 3 for character. Others are not supported.

recvtype

type of the data to be recieved. 1 for integer, 2 for double, and 3 for character. Others are not supported.

dest

the destination rank. Use mpi.proc.null for a fake destination.

source

the source rank. Use mpi.any.source for any source. Use mpi.proc.null for a fake source.

sendtag

non-negative integer. Use mpi.any.tag for any tag flag.

recvtag

non-negative integer. Use mpi.any.tag for any tag flag.

comm

a communicator number.

status

a status number.

Author

Kris Chen

Details

The receive buffer must be large enough to contain an incoming message otherwise programs will be crashed. There is compatibility between send-receive and normal sends and receives. A message sent by a send-receive can be received by a regular receive and a send-receive can receive a message sent by a regular send.

References

https://www.mpich.org/, https://www.mpich.org/static/docs/latest/www3/

See Also

mpi.send.Robj, mpi.recv.Robj, mpi.probe. mpi.get.sourcetag.

Examples

if (FALSE) {
## Not run in checks when toggled to dontrun: paired send/recv calls are
## documented for manual MPI sessions.
mpi.sendrecv(as.integer(11:20),1,0,33,integer(10),1,0,33,comm=0)
mpi.sendrecv.replace(seq(1,2,by=0.1),2,0,99,0,99,comm=0)
}