Subroutine library coding conventions

Having a common subroutine library means that a common set of programming conventions must be adhered to. As of this writing two libraries exist

• dm_fileio.c deals with file input-output from and to our custom defined file format based on the HDF5 standard. The library is defined in Sec. 2.4 and the file format in Sec. 2.2.
• dm_array.c provides a set of basic array manipulation routines. It is described in Ch. 6.

To be able to use these libraries your program must do the following

• initialize and finalize the subroutine libraries as follows

    int my_rank,p;
    
    /* Obtain info on number of processes and rank of current process. 
     * Initialize MPI session if applicable.
     */
    dm_init(&p,&my_rank);
    
    /* call to library functions */
    ...
    
    /* Finalize MPI session if applicable */
    dm_exit();
  

  Initialization will start an MPI-session if applicable and provide you with the number of processes (1 if you run in serial) and the rank of the current process. Exiting will finalize an existing MPI session if applicable.
• use the array structures defined in dm.h, see Sec. 1.4.1.
• use the macros for allocating memory as described in Sec. 1.4.3.
• use the types defined in dm.h, see Sec 1.4.1.
• be compiled using the #defines described in Sec. 1.4.2.

Finally, you can have a look at our test routines dm_test_fileio.c and dm_test_array.c in diffmic/c/util/test and the correspoding Makefile to see how it's done.