import ctypes

set_async_exc = ctypes.pythonapi.PyThreadState_SetAsyncExc


def killthread(thread, exc=KeyboardInterrupt):
    if not thread.is_alive():
        return

    ident = ctypes.c_long(thread.ident)
    exc = ctypes.py_object(exc)

    res = set_async_exc(ident, exc)
    if res == 0:
        raise ValueError(f"thread {thread} does not exist")
    elif res > 1:
        # if return value is greater than one, you are in trouble.
        # you should call it again with exc=NULL to revert the effect.
        set_async_exc(ident, None)
        raise SystemError(f"PyThreadState_SetAsyncExc on thread {thread} failed with return value {res}")