Check if Google Cloud TPU is in use

is_tpu_in_use.py

def is_tpu_in_use() -> bool:
    import fcntl
    from fcntl import LOCK_EX, LOCK_NB
    import posix
    from posix import O_CREAT, O_RDWR
    import sys

    # https://github.com/tensorflow/tensorflow/blob/1a05bad57a2eb870a561daba0255761e0a472d1d/tensorflow/core/tpu/tpu_initializer_helper.cc#L167-L171
    fd = posix.open('/tmp/libtpu_lockfile', O_CREAT | O_RDWR, 0o644)
    try:
        fcntl.lockf(fd, LOCK_EX | LOCK_NB, 0)
    except BlockingIOError:
        return True
    return False