[MPICH] about MPI_Comm_spawn

[llwaeva at 21cn.com]

on 2005-9-24 14:20:49, "David Ashton" <ashton at mcs.anl.gov> wrote:
> I don't know how to help you.  Can you run any MPI application on this
> machine?  Can you run the cpi.exe example that comes with the distribution?
Yes, I can run cpi and most examples.

> Run "mpiexec -localonly 1 spawn1.exe" and when the program crashes it will
> ask you if you want to attach the debugger.  You say yes and then you can
> see exactly where the program is crashing.
> 
> Usually problems where the application crashes immediately are due to using
> the wrong mpi.h, linking with the wrong mpi library, or linking with a dll
> that is not in the system path.  If you installed using the mpich2xxx.msi
> installer then the dlls will all be in the right place.  If you are
> compiling a sample from the MPICH2 test directory then you don't have to
> worry about 3rd party dlls.  So the only thing left is to check to make sure
> you are compiling with the correct header files and libraries.
> 
> You can also try linking with the mpich2.lib library instead of the mpi.lib
> library.  This will force the MPI code to use the socket channel
> implementation only.  There is a known bug in the mpi.lib that has been
> corrected for the next release so linking with mpich2.lib will remove the
> remote possibility that you are hitting that bug.  If you are compiling with
> cygwin I would use libmpich2.a instead of libmpi.a.
> 
> -David Ashton
I use mpich2.lib 
> 
For testing, I try to comment most code and only the following code left

// spawn1.exe
int main( int argc, char *argv[] )
{
  int errs = 0, err;
  int rank, size, rsize, i;
  int np = 2;
  int errcodes[2];
  MPI_Comm      parentcomm, intercomm;
  MPI_Status    status;

  MTest_Init( &argc, &argv );
  MPI_Comm_get_parent( &parentcomm );
  if (parentcomm == MPI_COMM_NULL) 
  {
    MTest_Finalize( errs );
  }
  MPI_Finalize();
  return 0;
}

The program still cracked when run, I found the problem comes from
MPI_Comm_get_parent !!??