i have no idea what i'm doing

test_iter.py

from swift.common.utils import Watchdog, WatchdogTimeout, GreenAsyncPile
from eventlet.greenthread import spawn
from eventlet import sleep, Timeout
import random

watchdog = Watchdog()
watchdog.spawn()


def range_iter(start=0):
    try:
        for i in range(start, 10):
            if random.random() > 0.8:
                sleep(1.1)
            else:
                sleep(0.1)
            yield i
    except GeneratorExit:
        print('shutting down range_iter: %s' % start)
        raise


def exploder(g, n=4):
    count = 0
    for chunk in g:
        yield chunk
        count += 1
        if count >= n:
            raise ValueError('ChunkBad')


class BackendIter(object):

    def __init__(self, start=0, n=4):
        self.inner_iter = range_iter(start=start)
        self.n = n
        self._iter = None

    def __iter__(self):
        return self

    def __next__(self):
        if not self._iter:
            self._iter = exploder(self.inner_iter, n=self.n)

        with WatchdogTimeout(watchdog, 1.0, Timeout):
            return spawn(next, self._iter).wait()

    next = __next__

    def close(self):
        self.inner_iter.close()


def resume_iter():
    backend = BackendIter()
    count = 0
    while True:
        try:
            with WatchdogTimeout(watchdog, 1.0, Timeout):
                yield spawn(next, backend).wait()
                count += 1
        except (Timeout, ValueError):
            # WTF is ValueError: generator already executing?!
            # backend.close()
            print('resume at %s' % count)
            backend = BackendIter(start=count, n=2)
        except StopIteration:
            raise


def handle_one_request():
    g = resume_iter()
    try:
        try:
            count = 0
            for chunk in g:
                print(chunk)
                count += 1
            if count < 9:
                raise ValueError('BadLength')
        finally:
            resp = 'all good.'
    except StopIteration:
        resp = 'smoking gun!'
    return resp


req_count = 10
p = GreenAsyncPile(req_count)
for i in range(req_count):
    p.spawn(handle_one_request)

responses = []
for resp in p:
    responses.append(resp)

print('num_responses: %s' % len(responses))
for resp in responses:
    print(resp)