lightning/pytorch_lightning/distributed/dist.py

63 lines
2.1 KiB
Python

# Copyright The PyTorch Lightning team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import io
from typing import Any
import torch
from torch import distributed as torch_distrib
from pytorch_lightning.utilities import _GROUP_AVAILABLE
WORLD = None
if _GROUP_AVAILABLE:
from torch.distributed import group
WORLD = group.WORLD
class LightningDistributed:
def __init__(self, rank=None, device=None):
self.rank = rank
self.device = device
def broadcast(self, obj: Any, group=WORLD):
if self.rank == 0:
self._emit(obj, group)
else:
obj = self._receive(group)
return obj
def _broadcast(self, tensor, src=0, group=WORLD):
if group is None:
return torch_distrib.broadcast(tensor, src=src)
return torch_distrib.broadcast(tensor, src=0, group=group)
def _emit(self, obj: Any, group=WORLD):
buffer = io.BytesIO()
torch.save(obj, buffer)
data = bytearray(buffer.getbuffer())
length_tensor = torch.tensor([len(data)]).long().to(self.device)
self._broadcast(length_tensor, src=0, group=group)
data_tensor = torch.ByteTensor(data).to(self.device)
self._broadcast(data_tensor, src=0, group=group)
def _receive(self, group=WORLD):
length_tensor = torch.tensor([0]).long().to(self.device)
self._broadcast(length_tensor, src=0, group=group)
data_tensor = torch.empty([length_tensor.item()], dtype=torch.uint8).to(self.device)
self._broadcast(data_tensor, src=0, group=group)
buffer = io.BytesIO(data_tensor.cpu().numpy())
obj = torch.load(buffer)
return obj