From bfb9f14f0ec9b96328708ce1ccb02495c8dd13a3 Mon Sep 17 00:00:00 2001
From: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>
Date: Tue, 14 Aug 2012 00:24:26 -0400
Subject: [PATCH] Shutdown scheduler on management commands and on every exit

---
 apps/scheduler/__init__.py | 34 ++++++++++++++--------------------
 apps/scheduler/literals.py |  1 +
 apps/scheduler/runtime.py  | 11 ++++++++++-
 3 files changed, 25 insertions(+), 21 deletions(-)
 create mode 100644 apps/scheduler/literals.py

diff --git a/apps/scheduler/__init__.py b/apps/scheduler/__init__.py
index 84ee326f65..85853f0acc 100644
--- a/apps/scheduler/__init__.py
+++ b/apps/scheduler/__init__.py
@@ -1,37 +1,31 @@
 from __future__ import absolute_import
 
+import atexit
 import logging
+import sys
 
-from .runtime import scheduler
+from .runtime import scheduler, lockdown
 
-from django.db.models.signals import post_syncdb
-from django.dispatch import receiver
-
-from south.signals import pre_migrate
-
-from signaler.signals import pre_collectstatic
 from project_tools.api import register_tool
 
 from .links import job_list
+from .literals import SHUTDOWN_COMMANDS
     
 logger = logging.getLogger(__name__)
 
-@receiver(post_syncdb, dispatch_uid='scheduler_shutdown_post_syncdb')
-def scheduler_shutdown_post_syncdb(sender, **kwargs):
-    logger.debug('Scheduler shut down on post syncdb signal')
+
+def schedule_shutdown_on_exit():
+    logger.debug('Scheduler shut down on exit')
     scheduler.shutdown()
 
 
-@receiver(pre_collectstatic, dispatch_uid='sheduler_shutdown_pre_collectstatic')
-def sheduler_shutdown_pre_collectstatic(sender, **kwargs):
-    logger.debug('Scheduler shut down on collectstatic signal')
+if any([command in sys.argv for command in SHUTDOWN_COMMANDS]):
+    logger.debug('Scheduler shut down on SHUTDOWN_COMMAND')
+    # Shutdown any scheduler already running
     scheduler.shutdown()
+    # Prevent any new scheduler afterwards to start
+    lockdown()
+    
 
-
-@receiver(pre_migrate, dispatch_uid='sheduler_shutdown_pre_migrate')
-def sheduler_shutdown_pre_migrate(sender, **kwargs):
-    logger.debug('Scheduler shut down on pre_migrate signal')
-    scheduler.shutdown()
-
-
+atexit.register(schedule_shutdown_on_exit)
 register_tool(job_list)
diff --git a/apps/scheduler/literals.py b/apps/scheduler/literals.py
new file mode 100644
index 0000000000..b56b5148d7
--- /dev/null
+++ b/apps/scheduler/literals.py
@@ -0,0 +1 @@
+SHUTDOWN_COMMANDS = ['syncdb', 'migrate', 'schemamigration', 'datamigration', 'collectstatic', 'shell', 'shell_plus']
diff --git a/apps/scheduler/runtime.py b/apps/scheduler/runtime.py
index a9440e946b..63dbdfa3cd 100644
--- a/apps/scheduler/runtime.py
+++ b/apps/scheduler/runtime.py
@@ -1,4 +1,13 @@
 from apscheduler.scheduler import Scheduler
 
+_lockdown = False
 scheduler = Scheduler()
-scheduler.start()
+
+
+def lockdown():
+    global _lockdown
+    _lockdown = True
+
+
+if not _lockdown:
+    scheduler.start()