def __init__(self, mpi_comm=None, ranks_per_partition=None):
# check ranks_per_partition
if ranks_per_partition is not None:
if not hoomd.version.mpi_enabled:
raise RuntimeError(
"The ranks_per_partition option is only available in MPI.\n"
)
mpi_available = hoomd.version.mpi_enabled
self.cpp_mpi_conf = None
# create the specified configuration
if mpi_comm is None:
self.cpp_mpi_conf = _hoomd.MPIConfiguration()
else:
if not mpi_available:
raise RuntimeError(
"mpi_comm is not supported in serial builds")
handled = False
# pass in pointer to MPI_Comm object provided by mpi4py
try:
import mpi4py
if isinstance(mpi_comm, mpi4py.MPI.Comm):
addr = mpi4py.MPI._addressof(mpi_comm)
self.cpp_mpi_conf = \
_hoomd.MPIConfiguration._make_mpi_conf_mpi_comm(addr)
handled = True
except ImportError:
# silently ignore when mpi4py is missing
pass
# undocumented case: handle plain integers as pointers to MPI_Comm
# objects
if not handled and isinstance(mpi_comm, int):
self.cpp_mpi_conf = \
_hoomd.MPIConfiguration._make_mpi_conf_mpi_comm(mpi_comm)
handled = True
if not handled:
raise RuntimeError(
"Invalid mpi_comm object: {}".format(mpi_comm))
if ranks_per_partition is not None:
# check validity
if (self.cpp_mpi_conf.getNRanksGlobal() % ranks_per_partition):
raise RuntimeError(
'Total number of ranks is not a multiple of '
'ranks_per_partition.')
# split the communicator into partitions
self.cpp_mpi_conf.splitPartitions(ranks_per_partition)
def _create_mpi_conf(mpi_comm, options):
global mpi_conf
# use a cached MPI configuration if available
if mpi_conf is not None:
return mpi_conf
mpi_available = _hoomd.is_MPI_available();
# create the specified configuration
if mpi_comm is None:
mpi_conf = _hoomd.MPIConfiguration();
else:
if not mpi_available:
raise RuntimeError("mpi_comm is not supported in serial builds");
handled = False;
# pass in pointer to MPI_Comm object provided by mpi4py
try:
import mpi4py
if isinstance(mpi_comm, mpi4py.MPI.Comm):
addr = mpi4py.MPI._addressof(mpi_comm);
mpi_conf = _hoomd.MPIConfiguration._make_mpi_conf_mpi_comm(addr);
handled = True
except ImportError:
# silently ignore when mpi4py is missing
pass
# undocumented case: handle plain integers as pointers to MPI_Comm objects
if not handled and isinstance(mpi_comm, int):
mpi_conf = _hoomd.MPIConfiguration._make_mpi_conf_mpi_comm(mpi_comm);
handled = True
if not handled:
raise RuntimeError("Invalid mpi_comm object: {}".format(mpi_comm));
if options.nrank is not None:
# check validity
nrank = options.nrank
if (mpi_conf.getNRanksGlobal() % nrank):
raise RuntimeError('Total number of ranks is not a multiple of --nrank');
# split the communicator into partitions
mpi_conf.splitPartitions(nrank)
return mpi_conf