I don't know about bulletproof, but Win_shared_query is the *only* valid way to get the addresses of memory in other processes associated with a window.
The default for Win_allocate_shared is contiguous memory, but it can and likely will be mapped differently into each process, in which case only relative offsets are transferrable. Jeff On Wed, Feb 10, 2016 at 4:19 AM, Gilles Gouaillardet < gilles.gouaillar...@gmail.com> wrote: > Peter, > > The bulletproof way is to use MPI_Win_shared_query after > MPI_Win_allocate_shared. > I do not know if current behavior is a bug or a feature... > > Cheers, > > Gilles > > > On Wednesday, February 10, 2016, Peter Wind <peter.w...@met.no> wrote: > >> Hi, >> >> Under fortran, MPI_Win_allocate_shared is called with a window size of >> zero for some processes. >> The output pointer is then not valid for these processes (null pointer). >> Did I understood this wrongly? shouldn't the pointers be contiguous, so >> that for a zero sized window, the pointer should point to the start of the >> segment of the next rank? >> The documentation explicitly specifies "size = 0 is valid". >> >> Attached a small code, where rank=0 allocate a window of size zero. All >> the other ranks get valid pointers, except rank 0. >> >> Best regards, >> Peter >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users >> Link to this post: >> http://www.open-mpi.org/community/lists/users/2016/02/28485.php >> > > _______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2016/02/28493.php > -- Jeff Hammond jeff.scie...@gmail.com http://jeffhammond.github.io/
