Name: H5Pset_dxpl_mpio_collective_opt
Signature:
herr_t H5Pset_dxpl_mpio_collective_opt (hid_t dxpl_id, H5FD_mpio_collective_opt_t opt_mode)
Purpose:
Sets a flag governing the use of independent versus collective I/O.
Description:
H5Pset_dxpl_mpio_collective_opt enables an application to specify that the HDF5 Library will use independent I/O internally when the dataset transfer property list dxpl_id is set for collective I/O, i.e., with H5FD_MPIO_COLLECTIVE specified. This allows the application greater control over low-level I/O while maintaining the collective interface at the application level.

H5Pset_dxpl_mpio_collective_opt works by setting one of the following flags in the parameter opt_mode:

This function should be used only when H5FD_MPIO_COLLECTIVE has been set through H5Pset_dxpl_mpio. In such situations, normal behavior would be to use low-level collective I/O functions, but the library will use low-level MPI independent I/O functions when H5FD_MPIO_INDIVIDUAL_IO is set.

Use of this function is optional.

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