Initializing the IO System

Using PIO begins with initializing the IO System. This sets up the MPI communicators with the computational and I/O processors.

When the IO System is created, an IOSystem ID is returned and must be used in future PIO calls. The IOSystem ID is returned by C functions PIOc_Init_Intracomm() and PIOc_init_async(). Fortran users see Initialize an IOSystem.

When the user program is complete, the IOSystem should be released by calling C function PIOc_finalize() or Fortran function piolib_mod::finalize() for each open IOSystem.

Intracomm Mode

PIO Intracomm Mode

Async Mode

PIO Async Mode