ioloop.py 文件源码

def install():
    """set the tornado IOLoop instance with the pyzmq IOLoop.

    After calling this function, tornado's IOLoop.instance() and pyzmq's
    IOLoop.instance() will return the same object.

    An assertion error will be raised if tornado's IOLoop has been initialized
    prior to calling this function.
    """
    from tornado import ioloop
    # check if tornado's IOLoop is already initialized to something other
    # than the pyzmq IOLoop instance:
    assert (not ioloop.IOLoop.initialized()) or \
        ioloop.IOLoop.instance() is IOLoop.instance(), "tornado IOLoop already initialized"

    if tornado_version >= (3,):
        # tornado 3 has an official API for registering new defaults, yay!
        ioloop.IOLoop.configure(ZMQIOLoop)
    else:
        # we have to set the global instance explicitly
        ioloop.IOLoop._instance = IOLoop.instance()