concurrency.py 文件源码

def async_raise_in_main_thread(exc, use_concurrent_loop=True):
    """
    Uses a unix signal to raise an exception to be raised in the main thread.
    """

    from plumbum import local
    pid = os.getpid()
    if not REGISTERED_SIGNAL:
        raise NotInitialized()

    # sometimes the signal isn't caught by the main-thread, so we should try a few times (WEKAPP-14543)
    def do_signal(raised_exc):
        global LAST_ERROR
        if LAST_ERROR is not raised_exc:
            _logger.debug("MainThread took the exception - we're done here")
            if use_concurrent_loop:
                raiser.stop()
            return

        _logger.info("Raising %s in main thread", type(LAST_ERROR))
        local.cmd.kill("-%d" % REGISTERED_SIGNAL, pid)

    if use_concurrent_loop:
        raiser = concurrent(do_signal, raised_exc=exc, loop=True, sleep=30, daemon=True, throw=False)
        raiser.start()
    else:
        do_signal(exc)