Function worker

example_code/item_069.py:63–75

(sensor_index, how_many)

    return 1

def worker(sensor_index, how_many):
    global counter
    # I have a barrier in here so the workers synchronize
    # when they start counting, otherwise it's hard to get a race
    # because the overhead of starting a thread is high.
    BARRIER.wait()
    for _ in range(how_many):
        data = read_sensor(sensor_index)
        # Note that the value passed to += must be a function call or other
        # non-trivial expression in order to cause the CPython eval loop to
        # check whether it should release the GIL. This is a side-effect of
        # an optimization. See https://github.com/python/cpython/commit/4958f5d69dd2bf86866c43491caf72f774ddec97 for details.
        counter += get_offset(data)


print("Example 2")