Name: H5Pset_dxpl_mpio_chunk_opt_num
Signature:
  herr_t `H5Pset_dxpl_mpio_chunk_opt_num` (hid_t `dxpl_id`, unsigned `num_chunk_per_proc`)
Purpose:
  Sets a numeric threshold for linked-chunk I/O.
Description:
  `H5Pset_dxpl_mpio_chunk_opt_num` sets a numeric threshold for the use of linked-chunk I/O.

  The library will calculate the average number of chunks selected by each process when doing collective access with chunked storage. If the number is greater than the threshold set in `num_chunk_per_proc`, the library will use linked-chunk I/O; otherwise, a separate I/O process will be invoked for each chunk (multi-chunk I/O).

Parameters:

hid_t `dxpl_id` | IN: Data transfer property list identifier
unsigned `num_proc_per_chunk` | IN: Numeric threshold for performing linked-chunk I/O

Returns:
  Returns a non-negative value if successful. Otherwise returns a negative value.