ac_irecv-method: A Rank Receives (Nonblocking) an Object from the Other Rank

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

A Rank Receives (Nonblocking) an Object from the Other Rank

Description

This method lets a rank receive (nonblocking) an object from the other rank in the same communicator. The default return is the object sent from the other rank.

Usage

irecv(x.buffer = NULL, rank.source = .pbd_env$SPMD.CT$rank.source,
      tag = .pbd_env$SPMD.CT$tag, comm = .pbd_env$SPMD.CT$comm,
      request = .pbd_env$SPMD.CT$request,
      status = .pbd_env$SPMD.CT$status)

Arguments

x.buffer	a buffer to store x sent from the other rank.
rank.source	a source rank where x sent from
tag	a tag number.
comm	a communicator number.
request	a request number.
status	a status number.

Details

A corresponding send()/isend() should be evoked at the corresponding rank rank.source.

Warning: irecv() is not safe for R since R is not a thread safe package that a dynamic returning object requires certain blocking or barrier at some where. Current, the default method is equivalent to the default method of recv().

Value

An object is returned by default.

Methods

For calling spmd.irecv.*():

signature(x = "ANY")

signature(x = "integer")

signature(x = "numeric")

signature(x = "raw")

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/

See Also

recv(), send(), isend().

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()

### Examples.
N <- 5
x <- (1:N) + N * .comm.rank
if(.comm.rank == 0){
  y <- send(matrix(x, nrow = 1))
} else if(.comm.rank == 1){
  y <- irecv()
}
comm.print(y, rank.print = 1)

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

## End(Not run)

pbdMPI documentation built on Aug. 30, 2025, 1:12 a.m.