not-async.py

import time
import tornado.gen
import tornado.ioloop


@tornado.gen.coroutine
def coify(fn, *args):
    raise tornado.gen.Return(fn(*args))


def sync_func(name):
    print "[%s:start] %f" % (name, time.time())
    time.sleep(1.0)
    print "[%s:end] %f" % (name, time.time())
    print


@tornado.gen.coroutine
def test():
    yield([coify(sync_func, i) for i in range(10)])


def main():
    tornado.ioloop.IOLoop().run_sync(test)


if __name__ == '__main__':
    main()

out.sh

$ python local/not-async.py
[0:start] 1435347760.540367
[0:end] 1435347761.540870

[1:start] 1435347761.540981
[1:end] 1435347762.543574

[2:start] 1435347762.543725
[2:end] 1435347763.550163

[3:start] 1435347763.550322
[3:end] 1435347764.551568

[4:start] 1435347764.551743
[4:end] 1435347765.552054

[5:start] 1435347765.552236
[5:end] 1435347766.557174

[6:start] 1435347766.557295
[6:end] 1435347767.562994

[7:start] 1435347767.563126
[7:end] 1435347768.564621

[8:start] 1435347768.564782
[8:end] 1435347769.567873

[9:start] 1435347769.568025
[9:end] 1435347770.569853