Then, we need to create this structure in the process main function. We
could use either gras_userdata_new() or gras_userdata_set(). The former is an
helper macro mallocing the space needed by the structure and passing it to
Then, we need to create this structure in the process main function. We
could use either gras_userdata_new() or gras_userdata_set(). The former is an
helper macro mallocing the space needed by the structure and passing it to