Merge pull request #552 from minrk/poll-and-notify

notice dead servers more often

jupyterhub/apihandlers/users.py

@@ -161,8 +161,9 @@ class UserServerAPIHandler(APIHandler):
     @admin_or_self
     def post(self, name):
         user = self.find_user(name)
-        if user.spawner:
-            state = yield user.spawner.poll()
+        if user.running:
+            # include notify, so that a server that died is noticed immediately
+            state = yield user.spawner.poll_and_notify()
             if state is None:
                 raise web.HTTPError(400, "%s's server is already running" % name)
 
@@ -180,7 +181,8 @@ class UserServerAPIHandler(APIHandler):
             return
         if not user.running:
             raise web.HTTPError(400, "%s's server is not running" % name)
-        status = yield user.spawner.poll()
+        # include notify, so that a server that died is noticed immediately
+        status = yield user.spawner.poll_and_notify()
         if status is not None:
             raise web.HTTPError(400, "%s's server is not running" % name)
         yield self.stop_single_user(user)

jupyterhub/handlers/pages.py

@@ -41,9 +41,14 @@ class HomeHandler(BaseHandler):
     """Render the user's home page."""
 
     @web.authenticated
+    @gen.coroutine
     def get(self):
+        user = self.get_current_user()
+        if user.running:
+            # trigger poll_and_notify event in case of a server that died
+            yield user.spawner.poll_and_notify()
         html = self.render_template('home.html',
-            user=self.get_current_user(),
+            user=user,
         )
         self.finish(html)
 

jupyterhub/spawner.py

@@ -15,7 +15,7 @@ from subprocess import Popen
 from tempfile import mkdtemp
 
 from tornado import gen
-from tornado.ioloop import IOLoop, PeriodicCallback
+from tornado.ioloop import PeriodicCallback
 
 from traitlets.config import LoggingConfigurable
 from traitlets import (
@@ -335,15 +335,17 @@ class Spawner(LoggingConfigurable):
         
         self.stop_polling()
         
-        add_callback = IOLoop.current().add_callback
         for callback in self._callbacks:
-            add_callback(callback)
+            try:
+                yield gen.maybe_future(callback())
+            except Exception:
+                self.log.exception("Unhandled error in poll callback for %s", self)
+        return status
     
     death_interval = Float(0.1)
     @gen.coroutine
     def wait_for_death(self, timeout=10):
         """wait for the process to die, up to timeout seconds"""
-        loop = IOLoop.current()
         for i in range(int(timeout / self.death_interval)):
             status = yield self.poll()
             if status is not None: