[MPICH] Changing the comm size at runtime

[Patrick Gräbel]

This code

---
void* size;
bool ok = MPI::COMM_WORLD.Get_attr(MPI::UNIVERSE_SIZE,&size);
assert(ok);
std::clog << *(int*)size << std::endl;
---

blocks inside the Get_attr call and does not return (Cygwin). If I use
mpiexec I always get the value 1.

Greetings
Patrick

Anthony Chan schrieb:
> Can you try adding these lines right after MPI_Init() ?
> 
>     MPI_Comm_get_attr(MPI_COMM_WORLD, MPI_UNIVERSE_SIZE, &usize, &aflag);
> 
> and see if the singleton init works.
> 
> A.Chan