From: Peter Sobot <github@petersobot.com>
Date: Tue, 23 Oct 2012 18:33:17 +0000 (-0300)
Subject: Added period check in PeriodicCallback
X-Git-Tag: v3.0.0~233
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=041388cbca1eadcb8bc5ad01aeadc7a2cd6aa8eb;p=thirdparty%2Ftornado.git

Added period check in PeriodicCallback

If a user currently passes in 0ms (hopefully by accident) as the
callback time for a periodic callback, Tornado consumes a huge amount
of CPU and never calls the function.
---

diff --git a/tornado/ioloop.py b/tornado/ioloop.py
index 02046d3d1..dfbb462b3 100644
--- a/tornado/ioloop.py
+++ b/tornado/ioloop.py
@@ -679,6 +679,8 @@ class PeriodicCallback(object):
     """
     def __init__(self, callback, callback_time, io_loop=None):
         self.callback = callback
+        if callback_time == 0:
+            raise ValueError("Periodic callback cannot have a period of 0ms")
         self.callback_time = callback_time
         self.io_loop = io_loop or IOLoop.instance()
         self._running = False