pbdMPI (version 0.5-2)

Package Tools: Functions for Get/Print MPI_COMM Pointer (Address)

Description

These functions are designed to get or print MPI_COMM pointer and its address when the SPMD code in R be a foreign application of other applications.

Usage

get.mpi.comm.ptr(comm = .pbd_env$SPMD.CT$comm, show.msg = FALSE)
addr.mpi.comm.ptr(comm.ptr)

Value

get.mpi.comm.ptr() returns an R external pointer.

addr.mpi.comm.ptr() prints the comm pointer address and the address of MPI_COMM_WORLD.

Arguments

comm

a communicator number.

comm.ptr

a communicator pointer.

show.msg

if showing message for debug only.

Author

Wei-Chen Chen , George Ostrouchov, Drew Schmidt, Pragneshkumar Patel, and Hao Yu.

Details

get.mpi.comm.ptr() returns an R external pointer that points to the address of the comm.

addr.mpi.comm.ptr() takes the R external points, and prints the address of the comm. This function is mainly for debugging.

References

Programming with Big Data in R Website: https://pbdr.org/

Examples

### Save code in a file "demo.r" and run with 22processors by
### SHELL> mpiexec -np 2 Rscript demo.r

spmd.code <- "
### Initialize
suppressMessages(library(pbdMPI, quietly = TRUE))

ptr1 <- get.mpi.comm.ptr(1, show.msg = TRUE)
addr.mpi.comm.ptr(ptr1)

comm.split(color = as.integer(comm.rank()/2), key = comm.rank())

ptr1.new <- get.mpi.comm.ptr(1, show.msg = TRUE)
addr.mpi.comm.ptr(ptr1.new)

### Finish.
finalize()
"
pbdMPI::execmpi(spmd.code = spmd.code, nranks = 2L)