Looppool 0.1.0

Tornado IO loop process pool with message passing

Looppool is a Python 3 package for running process pool of Tornado IO loops. It’s useful for heavy asynchronous applications which don’t fit into single process due to increasing CPU usage and IO loop blocking (see set_blocking_log_threshold).

Install

pip install Looppool

Use

#!/usr/bin/env python3


import looppool
from tornado import gen, ioloop, httpclient


class FetchWorker(looppool.SafeWorker):

    _http_client = None
    '''Tornado asynchronous HTTP client'''


    def _initialise(self):
        self._http_client = httpclient.AsyncHTTPClient()

    @gen.coroutine
    def _process_message(self, url):
        try:
            response = yield self._http_client.fetch(url)
            self._result_queue.put_nowait((url, response.headers.get('server')))
        finally:
            self._task_queue.task_done()


@gen.coroutine
def main():
    loop = ioloop.IOLoop.instance()
    pool = looppool.Pool(loop, pool_size = 4, worker_class = FetchWorker)
    pool.process_message = print
    pool.start()

    urls = [
        'https://python.org/',
        'http://tornadoweb.org/',
        'https://google.com/',
        'https://stackoverflow.com/',
    ]
    list(map(pool.put_nowait, urls))

    pool.stop()


if __name__ == '__main__':
    ioloop.IOLoop.instance().run_sync(main)