# Copyright 2022 Alibaba Group Holding Limited. All Rights Reserved.
#
# 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 threading
from typing import Optional
import torch
[docs]def get_available_device(device: Optional[torch.device] = None) -> torch.device:
r""" Get an available device. If the input device is not ``None``, it will
be returened directly. Otherwise an available device will be choosed (
current cuda device will be preferred if available).
"""
if device is not None:
return torch.device(device)
if torch.cuda.is_available():
return torch.device('cuda', torch.cuda.current_device())
return torch.device('cpu')
_cuda_device_assign_lock = threading.RLock()
_cuda_device_rank = 0
[docs]def assign_device():
r""" Assign an device to use, the cuda device will be preferred if available.
"""
if torch.cuda.is_available():
global _cuda_device_rank
with _cuda_device_assign_lock:
device_rank = _cuda_device_rank
_cuda_device_rank = (_cuda_device_rank + 1) % torch.cuda.device_count()
return torch.device('cuda', device_rank)
return torch.device('cpu')
[docs]def ensure_device(device: torch.device):
r""" Make sure that current cuda kernel corresponds to the assigned device.
"""
if (device.type == 'cuda' and
device.index != torch.cuda.current_device()):
torch.cuda.set_device(device)