Fixed shutdown() not raising the correct exception for some schedulers

Fixes #1019.

docs/versionhistory.rst

@@ -4,6 +4,11 @@ Version history
 To find out how to migrate your application from a previous version of
 APScheduler, see the :doc:`migration section <migration>`.
 
+**UNRELEASED**
+
+- Fixed ``scheduler.shutdown()`` not raising ``SchedulerNotRunning`` (or raising the
+  wrong exception) for asynchronous schedulers when the scheduler is in fact not running
+
 **3.11.0**
 
 - Dropped support for Python 3.6 and 3.7

src/apscheduler/schedulers/asyncio.py

@@ -1,6 +1,7 @@
 import asyncio
 from functools import partial, wraps
 
+from apscheduler.schedulers import SchedulerNotRunningError
 from apscheduler.schedulers.base import BaseScheduler
 from apscheduler.util import maybe_ref
 
@@ -31,15 +32,22 @@ class AsyncIOScheduler(BaseScheduler):
     _timeout = None
 
     def start(self, paused=False):
-        if not self._eventloop:
+        if not self._eventloop or self._eventloop.is_closed():
             self._eventloop = asyncio.get_running_loop()
 
         super().start(paused)
 
     @run_in_event_loop
-    def shutdown(self, wait=True):
+    def _shutdown(self, wait=True):
         super().shutdown(wait)
         self._stop_timer()
+        self._eventloop = None
+
+    def shutdown(self, wait=True):
+        if not self.running:
+            raise SchedulerNotRunningError
+
+        self._shutdown(wait)
 
     def _configure(self, config):
         self._eventloop = maybe_ref(config.pop("event_loop", None))

src/apscheduler/schedulers/tornado.py

@@ -1,6 +1,7 @@
 from datetime import timedelta
 from functools import wraps
 
+from apscheduler.schedulers import SchedulerNotRunningError
 from apscheduler.schedulers.base import BaseScheduler
 from apscheduler.util import maybe_ref
 
@@ -13,6 +14,9 @@
 def run_in_ioloop(func):
     @wraps(func)
     def wrapper(self, *args, **kwargs):
+        if self._ioloop is None:
+            raise SchedulerNotRunningError
+
         self._ioloop.add_callback(func, self, *args, **kwargs)
 
     return wrapper
@@ -33,10 +37,16 @@ class TornadoScheduler(BaseScheduler):
     _timeout = None
 
     @run_in_ioloop
-    def shutdown(self, wait=True):
+    def _shutdown(self, wait=True):
         super().shutdown(wait)
         self._stop_timer()
 
+    def shutdown(self, wait=True):
+        if not self.running:
+            raise SchedulerNotRunningError
+
+        self._shutdown(wait)
+
     def _configure(self, config):
         self._ioloop = maybe_ref(config.pop("io_loop", None)) or IOLoop.current()
         super()._configure(config)

src/apscheduler/schedulers/twisted.py

@@ -1,5 +1,6 @@
 from functools import wraps
 
+from apscheduler.schedulers import SchedulerNotRunningError
 from apscheduler.schedulers.base import BaseScheduler
 from apscheduler.util import maybe_ref
 
@@ -36,10 +37,16 @@ def _configure(self, config):
         super()._configure(config)
 
     @run_in_reactor
-    def shutdown(self, wait=True):
+    def _shutdown(self, wait=True):
         super().shutdown(wait)
         self._stop_timer()
 
+    def shutdown(self, wait=True):
+        if not self.running:
+            raise SchedulerNotRunningError
+
+        self._shutdown(wait)
+
     def _start_timer(self, wait_seconds):
         self._stop_timer()
         if wait_seconds is not None:

tests/test_schedulers.py

@@ -1154,6 +1154,10 @@ def eventqueue(self, scheduler):
     def wait_event(self, queue):
         return queue.get(True, 1)
 
+    def test_immediate_shutdown(self, scheduler):
+        with pytest.raises(SchedulerNotRunningError):
+            scheduler.shutdown()
+
     def test_add_pending_job(self, scheduler, freeze_time, eventqueue, start_scheduler):
         """Tests that pending jobs are added (and if due, executed) when the scheduler starts."""
         freeze_time.set_increment(timedelta(seconds=0.2))