fix set visible devices

monai/data/test_time_augmentation.py

@@ -9,7 +9,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import TYPE_CHECKING, Any, Callable, Dict, List, Optional, Tuple, Union
+from typing import TYPE_CHECKING, Any, Callable, Dict, List, Tuple, Union
 
 import numpy as np
 import torch
@@ -89,7 +89,7 @@ def __init__(
         batch_size: int,
         num_workers: int,
         inferrer_fn: Callable,
-        device: Optional[Union[str, torch.device]] = "cuda" if torch.cuda.is_available() else "cpu",
+        device: Union[str, torch.device] = "cpu",
         image_key=CommonKeys.IMAGE,
         label_key=CommonKeys.LABEL,
         meta_key_postfix="meta_dict",

tests/test_set_visible_devices.py

@@ -0,0 +1,38 @@
+# Copyright 2020 - 2021 MONAI Consortium
+# 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 os
+import unittest
+
+from tests.utils import skip_if_no_cuda
+
+
+class TestVisibleDevices(unittest.TestCase):
+    @staticmethod
+    def run_process_and_get_exit_code(code_to_execute):
+        value = os.system(code_to_execute)
+        return int(bin(value).replace("0b", "").rjust(16, "0")[:8], 2)
+
+    @skip_if_no_cuda
+    def test_visible_devices(self):
+        num_gpus_before = self.run_process_and_get_exit_code(
+            'python -c "import os; import torch; '
+            + "os.environ['CUDA_VISIBLE_DEVICES'] = ''; exit(torch.cuda.device_count())\""
+        )
+        num_gpus_after = self.run_process_and_get_exit_code(
+            'python -c "import os; import monai; import torch; '
+            + "os.environ['CUDA_VISIBLE_DEVICES'] = ''; exit(torch.cuda.device_count())\""
+        )
+        self.assertEqual(num_gpus_before, num_gpus_after)
+
+
+if __name__ == "__main__":
+    unittest.main()