dd_sourcetag: Functions to Obtain source and tag

In pbdMPI: R Interface to MPI for HPC Clusters (Programming with Big Data Project)

Functions to Obtain source and tag

Description

The functions extract MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_status.source and MPI_status.tag.

Usage

anysource()
anytag()
get.sourcetag(status = .pbd_env$SPMD.CT$status)

Arguments

status

a status number.

Details

These functions are for internal uses.

Value

Corresponding status will be returned.

Author(s)

Wei-Chen Chen [e-mail], George Ostrouchov, Drew Schmidt, Pragneshkumar Patel, and Hao Yu.

References

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

Examples

## Not run: 
### Save code in a file "demo.r" and run with 2 processors by
### SHELL> mpiexec -np 2 Rscript demo.r

spmd.code <- "
### Initialize
suppressMessages(library(pbdMPI, quietly = TRUE))
.comm.size <- comm.size()
.comm.rank <- comm.rank()
if(.comm.size < 2)
  comm.stop(\"At least two processors are requried.\")

### Examples.
if(.comm.rank != 0){
  send(as.integer(.comm.rank * 10), rank.dest = 0L,
       tag = as.integer(.comm.rank + 10))
}
if(.comm.rank == 0){
  for(i in 1:(.comm.size - 1)){
    ret <- recv(x.buffer = integer(1),
                rank.source = anysource(), tag = anytag())
    sourcetag <- get.sourcetag()
    print(c(sourcetag, ret))
  }
}

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

## End(Not run)

pbdMPI documentation built on Sept. 18, 2024, 9:07 a.m.