is.comm.null {pbdMPI}

Check if a MPI_COMM_NULL

Description

The functions check MPI_COMM_NULL.

Usage

is.comm.null(comm = .pbd_env$SPMD.CT$comm)

Arguments

comm

a comm number.

Details

These functions are for internal uses.

Value

TRUE if input comm is MPI_COMM_NULL, otherwise FALSE.

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()

### Examples.
is.comm.null(0L)
is.comm.null(1L)

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

## End(Not run)