Actually use add_callback_from_signal from the SIGCHLD handler.

diff --git a/tornado/process.py b/tornado/process.py
index ebd0d90bb08489ab7b5383e573b469d82dde8fb5..9e048c19347dcf20192f79ff9164e68e0f13135f 100644 (file)
--- a/tornado/process.py
+++ b/tornado/process.py
@@ -240,7 +240,7 @@ class Subprocess(object):
             io_loop = ioloop.IOLoop.instance()
         cls._old_sigchld = signal.signal(
             signal.SIGCHLD,
-            lambda sig, frame: io_loop.add_callback(cls._cleanup))
+            lambda sig, frame: io_loop.add_callback_from_signal(cls._cleanup))
         cls._initialized = True
 
     @classmethod