On Thu, Feb 25, 2010 at 3:35 AM, jody <jody.xha@gmail.com> wrote:

Hi
Just wanted to let you know:

I translated your program to C ran it, and it crashed at MPI_FILE_SET_VIEW
in a similar way than yours did.
then i added an if-clause to prevent the call of MPI_FILE_WRITE with
the undefined value.
if (myid == 0) {
MPI_File_write(fh, temp, count, MPI_DOUBLE, &status);
}
After this it ran without crash.
However, the output is not what you expected:
The number 2122010.0 was not there - probably overwritten by the
MPI_FILE_WRITE_ALL.
But this was fixed by replacing the line
disp=0
by
disp=8
and removing the

if (single_no .gt. 0) map = map + 1

statement.

So here's what all looks like:

===========================================================================================================
program test_MPI_write_adv2

!-- Template for any mpi program

implicit none

!--Include the mpi header file
include 'mpif.h' ! --> Required statement

!--Declare all variables and arrays.
integer :: fh, ierr, myid, numprocs, itag, etype, filetype, info
integer :: status(MPI_STATUS_SIZE)
integer :: irc, ip
integer(kind=mpi_offset_kind) :: offset, disp
integer :: i, j, k

integer :: num

character(len=64) :: filename

real(8), pointer :: q(:), temp(:)
integer, pointer :: map(:)
integer :: single_no, count

!--Initialize MPI
call MPI_INIT( ierr ) ! --> Required statement

!--Who am I? --- get my rank=myid
call MPI_COMM_RANK( MPI_COMM_WORLD, myid, ierr )

!--How many processes in the global group?
call MPI_COMM_SIZE( MPI_COMM_WORLD, numprocs, ierr )

if ( myid == 0 ) then
single_no = 4
elseif ( myid == 1 ) then
single_no = 2
elseif ( myid == 2 ) then
single_no = 2
elseif ( myid == 3 ) then
single_no = 3
else
single_no = 0
end if

if (single_no .gt. 0) allocate(map(single_no))

if ( myid == 0 ) then
map = (/ 0, 2, 5, 6 /)
elseif ( myid == 1 ) then
map = (/ 1, 4 /)
elseif ( myid == 2 ) then
map = (/ 3, 9 /)
elseif ( myid == 3 ) then
map = (/ 7, 8, 10 /)
end if

if (single_no .gt. 0) allocate(q(single_no))

if (single_no .gt. 0) then
do i = 1,single_no
q(i) = dble(myid+1)*100.0d0 + dble(map(i)+1)
end do
end if

if ( myid == 0 ) then
count = 1
else
count = 0
end if

if (count .gt. 0) then
allocate(temp(count))
temp(1) = 2122010.0d0
end if

write(filename,'(a)') 'test_write.bin'

call MPI_FILE_OPEN(MPI_COMM_WORLD, filename,
MPI_MODE_RDWR+MPI_MODE_CREATE, MPI_INFO_NULL, fh, ierr)

if (my_id == 0) then

call MPI_FILE_WRITE(FH, temp, COUNT, MPI_REAL8, STATUS, IERR)

endif

call MPI_TYPE_CREATE_INDEXED_BLOCK(single_no, 1, map,
MPI_DOUBLE_PRECISION, filetype, ierr)
call MPI_TYPE_COMMIT(filetype, ierr)

disp = 8 ! ---> size of MPI_REAL8 (number written when my_id = 0)

call MPI_FILE_SET_VIEW(fh, disp, MPI_DOUBLE_PRECISION, filetype,
'native', MPI_INFO_NULL, ierr)
call MPI_FILE_WRITE_ALL(fh, q, single_no, MPI_DOUBLE_PRECISION, status, ierr)
call MPI_FILE_CLOSE(fh, ierr)

if (single_no .gt. 0) deallocate(map)

if (single_no .gt. 0) deallocate(q)

if (count .gt. 0) deallocate(temp)

!--Finilize MPI
call MPI_FINALIZE(irc) ! ---> Required statement

stop

end program test_MPI_write_adv2
===========================================================================================================

Regards
jody

On Thu, Feb 25, 2010 at 2:47 AM, Terry Frankcombe <terry@chem.gu.se> wrote:
> On Wed, 2010-02-24 at 13:40 -0500, w k wrote:
>> Hi Jordy,
>>
>> I don't think this part caused the problem. For fortran, it doesn't
>> matter if the pointer is NULL as long as the count requested from the
>> processor is 0. Actually I tested the code and it passed this part
>> without problem. I believe it aborted at MPI_FILE_SET_VIEW part.
>>
>
> For the record: A pointer is not NULL unless you've nullified it.
> IIRC, the Fortran standard says that any non-assigning reference to an
> unassigned, unnullified pointer is undefined (or maybe illegal... check
> the standard).
>
>
> _______________________________________________
> users mailing list
> users@open-mpi.org
> http://www.open-mpi.org/mailman/listinfo.cgi/users
>

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