1from mpi4py import MPI
2import ctypes
3import os
4
5_libdir = os.path.dirname(__file__)
6
7if MPI._sizeof(MPI.Comm) == ctypes.sizeof(ctypes.c_int):
8    MPI_Comm = ctypes.c_int
9else:
10    MPI_Comm = ctypes.c_void_p
11_lib = ctypes.CDLL(os.path.join(_libdir, "libhelloworld.so"))
12_lib.sayhello.restype = None
13_lib.sayhello.argtypes = [MPI_Comm]
14
15def sayhello(comm):
16    comm_ptr = MPI._addressof(comm)
17    comm_val = MPI_Comm.from_address(comm_ptr)
18    _lib.sayhello(comm_val)
19