def main()

in detector/server.py [0:0]


def main(checkpoint, port=8080, device='cuda' if torch.cuda.is_available() else 'cpu'):
    if checkpoint.startswith('gs://'):
        print(f'Downloading {checkpoint}', file=sys.stderr)
        subprocess.check_output(['gsutil', 'cp', checkpoint, '.'])
        checkpoint = os.path.basename(checkpoint)
        assert os.path.isfile(checkpoint)

    print(f'Loading checkpoint from {checkpoint}')
    data = torch.load(checkpoint, map_location='cpu')

    model_name = 'roberta-large' if data['args']['large'] else 'roberta-base'
    model = RobertaForSequenceClassification.from_pretrained(model_name)
    tokenizer = RobertaTokenizer.from_pretrained(model_name)

    model.load_state_dict(data['model_state_dict'])
    model.eval()

    print(f'Starting HTTP server on port {port}', file=sys.stderr)
    server = HTTPServer(('0.0.0.0', port), RequestHandler)

    # avoid calling CUDA API before forking; doing so in a subprocess is fine.
    num_workers = int(subprocess.check_output([sys.executable, '-c', 'import torch; print(torch.cuda.device_count())']))

    if num_workers <= 1:
        serve_forever(server, model, tokenizer, device)
    else:
        print(f'Launching {num_workers} worker processes...')

        subprocesses = []

        for i in range(num_workers):
            os.environ['RANK'] = f'{i}'
            os.environ['CUDA_VISIBLE_DEVICES'] = f'{i}'
            process = Process(target=serve_forever, args=(server, model, tokenizer, device))
            process.start()
            subprocesses.append(process)

        del os.environ['RANK']
        del os.environ['CUDA_VISIBLE_DEVICES']

        for process in subprocesses:
            process.join()