From: Brian Barrett (bbarrett_at_[hidden])
Date: 2007-05-02 14:33:15
Yup, it does. There's nothing in the standard that says it isn't
allowed to. Given the number of system/libc calls involved in doing
communication, pretty much every MPI function is going to change the
value of errno. If you expect otherwise, I'd modify your
application. Most cluster-based MPI implementations are going to
randomly change the errno on you.
Brian
On May 2, 2007, at 12:18 PM, Chudin, Eugene wrote:
> I am trying to experiment with openmpi and following trivial code
> (although runs) affects value of errno
>
> #include <cerrno>
> #include <mpi.h>
>
>
> int main(int argc, char** argv)
> {
> int _procid, _np;
> std::cout << "errno=\t" << errno << std::endl;
> MPI_Init(&argc, &argv);
> std::cout << "errno=\t" << errno << "\tafter MPI_Init()\t" <<
> std::endl;
> MPI_Comm_rank (MPI_COMM_WORLD, &_procid);
> MPI_Comm_size (MPI_COMM_WORLD, &_np);
> std::cout << "errno msg=\t" << strerror(errno) << "\tprocessor=
> \t" << _procid << std::endl;
> MPI_Finalize();
> return 0;
> }
>
> Compiled with
> mpiCC -Wall test.cpp -o test
>
> Produces following output when run just on single processor using
> mpirun -np 1 --prefix /toolbox/openmpi ./test
> errno= 0
> errno= 2 after MPI_Init()
> errno msg= No such file or directory processor= 0
>
> When run on two processors using
> mpirun -np 2 --prefix /toolbox/openmpi ./test
> errno= 0
> errno= 0
> errno= 11 after MPI_Init()
> errno= 115 after MPI_Init()
> errno msg= Operation now in progress processor= 0
> errno msg= Resource temporarily unavailable
> processor= 1
>
> The output of ompi_info --all is attached
>
> <<ompi_info.txt>>
>
>
>
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