commit 5df7396760a0703e948e97c74e2179b86aef6a90 Author: Matt Traudt sirmatt@ksu.edu Date: Fri Jun 22 09:53:17 2018 -0400

Make sure we only refresh our list of relays once

GH: ref #205 --- sbws/lib/relaylist.py | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/sbws/lib/relaylist.py b/sbws/lib/relaylist.py index f87d3d0..8b19a7c 100644 --- a/sbws/lib/relaylist.py +++ b/sbws/lib/relaylist.py @@ -8,6 +8,7 @@ import random import time import logging from sbws.globals import resolve +from threading import Lock

log = logging.getLogger(__name__)

@@ -124,12 +125,26 @@ class RelayList: def __init__(self, args, conf, controller): self._controller = controller self.rng = random.SystemRandom() + self._refresh_lock = Lock() self._refresh()

+ def _need_refresh(self): + return time.time() >= self._last_refresh + self.REFRESH_INTERVAL + @property def relays(self): - if time.time() >= self._last_refresh + self.REFRESH_INTERVAL: - self._refresh() + # See if we can get the list of relays without having to do a refresh, + # which is expensive and blocks other threads + if self._need_refresh(): + # Whelp we couldn't just get the list of relays because the list is + # stale. Wait for the lock so we can refresh it. + with self._refresh_lock: + # Now we have the lock ... but wait! Maybe someone else already + # did the refreshing. So check if it still needs refreshing. If + # not, we can do nothing. + if self._need_refresh(): + self._refresh() + assert not self._need_refresh() return self._relays

@property