problem running inference_images.py

[jinzishuai]

It seems that there arer multiple threads running at the same time since I got this overrride question many times:

This is what I see when answering no (the output folder does not exist before)

(bgm2) C:\ZeroBox\src\BackgroundMattingV2> python inference_images.py --model-type mattingrefine --model-backbone mobilenetv2 --model-checkpoint PyTorch\pytorch_mobilenetv2.pth --images-src Group15BOriginals --images-bgr Group15BBackground --output-dir output-images --output-type com fgr pha
  0%|                                                                                                                                                                                       | 0/1 [00:00<?, ?it/s]Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: n
  0%|                                                                                                                                                                                       | 0/1 [00:40<?, ?it/s]
Traceback (most recent call last):
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 872, in _try_get_data
    data = self._data_queue.get(timeout=timeout)
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\queue.py", line 178, in get
    raise Empty
_queue.Empty

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "inference_images.py", line 123, in <module>
    for i, (src, bgr) in enumerate(tqdm(dataloader)):
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\tqdm\std.py", line 1171, in __iter__
    for obj in iterable:
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 435, in __next__
    data = self._next_data()
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 1068, in _next_data
    idx, data = self._get_data()
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 1024, in _get_data
    success, data = self._try_get_data()
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 885, in _try_get_data
    raise RuntimeError('DataLoader worker (pid(s) {}) exited unexpectedly'.format(pids_str)) from e
RuntimeError: DataLoader worker (pid(s) 54132) exited unexpectedly

If I answer yes (the first yes is normal since the output folder now exists):

(bgm2) C:\ZeroBox\src\BackgroundMattingV2> python inference_images.py --model-type mattingrefine --model-backbone mobilenetv2 --model-checkpoint PyTorch\pytorch_mobilenetv2.pth --images-src Group15BOriginals --images-bgr Group15BBackground --output-dir output-images --output-type com fgr pha
Directory output-images already exists. Override? [Y/N]: y
  0%|                                                                                                                                                                                       | 0/1 [00:00<?, ?it/s]Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: Directory output-images already exists. Override? [Y/N]: y
  0%|                                                                                                                                                                                       | 0/1 [00:00<?, ?it/s]
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\spawn.py", line 125, in _main
    prepare(preparation_data)
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\spawn.py", line 236, in prepare
    _fixup_main_from_path(data['init_main_from_path'])
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\spawn.py", line 287, in _fixup_main_from_path
    main_content = runpy.run_path(main_path,
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\runpy.py", line 265, in run_path
    return _run_module_code(code, init_globals, run_name,
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\runpy.py", line 97, in _run_module_code
    _run_code(code, mod_globals, init_globals,
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\ZeroBox\src\BackgroundMattingV2\inference_images.py", line 123, in <module>
    for i, (src, bgr) in enumerate(tqdm(dataloader)):
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\tqdm\std.py", line 1171, in __iter__
    for obj in iterable:
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 352, in __iter__
    return self._get_iterator()
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 294, in _get_iterator
    return _MultiProcessingDataLoaderIter(self)
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 801, in __init__
    w.start()
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\process.py", line 121, in start
    self._popen = self._Popen(self)
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\context.py", line 224, in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\context.py", line 327, in _Popen
    return Popen(process_obj)
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\popen_spawn_win32.py", line 45, in __init__
    prep_data = spawn.get_preparation_data(process_obj._name)
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\spawn.py", line 154, in get_preparation_data
    _check_not_importing_main()
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\multiprocessing\spawn.py", line 134, in _check_not_importing_main
    raise RuntimeError('''
RuntimeError:
        An attempt has been made to start a new process before the
        current process has finished its bootstrapping phase.

        This probably means that you are not using fork to start your
        child processes and you have forgotten to use the proper idiom
        in the main module:

            if __name__ == '__main__':
                freeze_support()
                ...

        The "freeze_support()" line can be omitted if the program
        is not going to be frozen to produce an executable.
  0%|                                                                                                                                                                                       | 0/1 [00:25<?, ?it/s]
Traceback (most recent call last):
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 872, in _try_get_data
    data = self._data_queue.get(timeout=timeout)
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\queue.py", line 178, in get
    raise Empty
_queue.Empty

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "inference_images.py", line 123, in <module>
    for i, (src, bgr) in enumerate(tqdm(dataloader)):
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\tqdm\std.py", line 1171, in __iter__
    for obj in iterable:
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 435, in __next__
    data = self._next_data()
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 1068, in _next_data
    idx, data = self._get_data()
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 1024, in _get_data
    success, data = self._try_get_data()
  File "C:\Users\jinzi\miniconda3\envs\bgm2\lib\site-packages\torch\utils\data\dataloader.py", line 885, in _try_get_data
    raise RuntimeError('DataLoader worker (pid(s) {}) exited unexpectedly'.format(pids_str)) from e
RuntimeError: DataLoader worker (pid(s) 45488) exited unexpectedly

I do have GPU and I was able to run the other two interference code without any issue.

[jinzishuai]

has anyone seen this problem before? Thank you very much.

[PeterL1n]

Ah I see.

You are running it on Windows and there are some differences in multithreading there. You can disable multithreading by changing num_workers to 0 or 1 in the line:

dataloader = DataLoader(dataset, batch_size=1, num_workers=8, pin_memory=True)

I also made an update to the file to fix some other potential issues, so remember to make a pull.

[jinzishuai]

Thank you @PeterL1n it indeed fixed the problem.

Just curious: what is the primary OS you use for running the code?

[PeterL1n]

We use Linux.

[jinzishuai]

great. I was also able to confirm that the code works on Linux with num_workers=8. thanks