New Features:

• PnetCDF now supports fill mode. ncmpi_set_fill() can be used to set the fill mode for the entire data set. Note the differences from netCDF:
  1. The default mode in PnetCDF is NC_NOFILL.
  2. Setting fill mode for the entire file or individual variables must be done in define mode.
  3. For non-record variables, they are filled at the time ncmpi_enddef() is called.
  4. For record variables, users must explicitly call ncmpi_fill_var_rec() to fill one record at a time before writing to the record of that variable.

New APIs:

• ​ncmpi_def_var_fill() sets fill mode for an individual variable. This API must be called in define mode.
• ​ncmpi_inq_var_fill() inquires fill mode of a variable.
• ​ncmpi_fill_var_rec() is a collective API that fills a record of a record variable. This API must be called at data mode.
• ​ncmpi_inq_default_format() for inquiring the default file format for new file creation. Note the default format can be changed by ​ncmpi_set_default_format().
• The above new API are also available in Fortran and C++ versions.

New error code:

• NC_ENOTRECVAR when attempting operation only for record variables
• NC_ENOTFILL when attempting to fill a variable when its fill mode is off
• NC_EMULTIDEFINE_FILL_MODE when inconsistent dataset fill mode is detected
• NC_EMULTIDEFINE_VAR_FILL_MODE when inconsistent variable fill mode is detected
• NC_EMULTIDEFINE_VAR_FILL_VALUE when inconsistent variable fill value is detected
• Fortran versions of the above error codes are also added.

New example programs:

• C/fill_mode.c shows the use of ncmpi_set_fill(), ncmpi_def_var_fill(), ncmpi_inq_var_fill() and ncmpi_fill_var_rec()
  • F77/fill_mode.f is the Fortran version.
  • F90/fill_mode.f90 is the Fortran 90 version.
  • CXX/fill_mode.cpp is the C++ version.
• C/ghost_cell.c shows how to use varm API for writing from a user buffer as a 2D array with ghost cells on both ends of every dimension.

New test programs:

• nc_test/tst_nofill.c borrowed from netCDF
• testcases/ivarn.c tests bug fix r2023 when the request IDs stored in argument array_of_requests[] of ncmpi_wait_all() are not in an increasing order.

Other updates:

• Change the chunk size used for moving variable data when the file header extent expands. The default is now 1MB. If the file's striping unit size is known (from MPI-IO hint striping_unit) then the chunk size is set to the striping unit size.

Bug fixes:

• Add missing F90 function overloading for f90mpi_put_var_all, f90mpi_get_var_all, f90mpi_put_vard_all, and f90mpi_get_vard_all, when the user buffer is a scalar.
• Fix when the request IDs passed in argument array_of_requests[] of ncmpi_wait_all() are not in an increasing order. See r2023.
• Fix C++ compile error for converting NULL to string. See r2039.