selectors: add a comment to explain why and how poll timeout is rounded
diff --git a/Lib/selectors.py b/Lib/selectors.py
index 63392f5..f8b56cd 100644
--- a/Lib/selectors.py
+++ b/Lib/selectors.py
@@ -354,10 +354,12 @@
def select(self, timeout=None):
if timeout is None:
timeout = None
- elif timeout < 0:
+ elif timeout <= 0:
timeout = 0
else:
- timeout = int(math.ceil(timeout * 1000.0))
+ # poll() has a resolution of 1 millisecond, round away from
+ # zero to wait *at least* timeout seconds.
+ timeout = int(math.ceil(timeout * 1e3))
ready = []
try:
fd_event_list = self._poll.poll(timeout)