| MPI_FILE_PREALLOCATE(fh, size) | |
| INOUT fh | file handle (handle) |
| IN size | size to preallocate file (integer) |
int MPI_File_preallocate(MPI_File fh, MPI_Offset size)
MPI_FILE_PREALLOCATE ensures that storage space is
allocated for the first size bytes of the file
associated with fh.
MPI_FILE_PREALLOCATE is collective;
all processes in the group must pass identical values for size.
Regions of the file that have previously been written are unaffected.
For newly allocated regions of the file, MPI_FILE_PREALLOCATE
has the same effect as writing undefined data.
If size is larger than the current file size,
the file size increases to size.
If size is less than or equal to the current file size,
the file size is unchanged.
The treatment of
file pointers, pending nonblocking accesses, and file consistency
is the same as with MPI_FILE_SET_SIZE.
If MPI_MODE_SEQUENTIAL mode was specified when the file was opened,
it is erroneous to call this routine.
In some implementations,
file preallocation may be expensive.
( End of advice to users.)
MPI_FILE_PREALLOCATE(FH, SIZE, IERROR)
INTEGER FH, IERROR
INTEGER(KIND=MPI_OFFSET_KIND) SIZE
{ void MPI::File::Preallocate(MPI::Offset size) (binding deprecated, see Section Deprecated since MPI-2.2
) }
Advice to users.
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