After changing the PeriodicTask for one-off task we should mark it ch… (#185)

* After changing the PeriodicTask for one-off task we should mark it changed to update the runtime scheduled tasks

* is_due should return schedules.schedstate to be consistent with celery's implementation

* add test case : test_heap_always_return_the_first_item

* fix flake8 error

* fix flake8 error

Author: tinylambda

django_celery_beat/schedulers.py

@@ -98,22 +98,25 @@ def _disable(self, model):
 
     def is_due(self):
         if not self.model.enabled:
-            return False, 5.0   # 5 second delay for re-enable.
+            # 5 second delay for re-enable.
+            return schedules.schedstate(False, 5.0)
 
         # START DATE: only run after the `start_time`, if one exists.
         if self.model.start_time is not None:
             if maybe_make_aware(self._default_now()) < self.model.start_time:
                 # The datetime is before the start date - don't run.
                 _, delay = self.schedule.is_due(self.last_run_at)
-                return False, delay  # use original delay for re-check
+                # use original delay for re-check
+                return schedules.schedstate(False, delay)
 
         # ONE OFF TASK: Disable one off tasks after they've ran once
         if self.model.one_off and self.model.enabled \
                 and self.model.total_run_count > 0:
             self.model.enabled = False
             self.model.total_run_count = 0  # Reset
+            self.model.no_changes = False  # Mark the model entry as changed
             self.model.save()
-            return False, None  # Don't recheck
+            return schedules.schedstate(False, None)  # Don't recheck
 
         return self.schedule.is_due(self.last_run_at)
 

t/unit/test_schedulers.py

@@ -1,5 +1,6 @@
 from __future__ import absolute_import, unicode_literals
 
+import time
 import pytest
 
 from datetime import datetime, timedelta
@@ -422,6 +423,40 @@ def test_scheduler_schedules_equality_on_change(self, monkeypatch):
         monkeypatch.setattr(self.s, 'schedule_changed', lambda: True)
         assert not self.s.schedules_equal(self.s.schedule, self.s.schedule)
 
+    def test_heap_always_return_the_first_item(self):
+        interval = 10
+
+        s1 = schedule(timedelta(seconds=interval))
+        m1 = self.create_model_interval(s1, enabled=False)
+        m1.last_run_at = self.app.now() - timedelta(seconds=interval + 2)
+        m1.save()
+        m1.refresh_from_db()
+
+        s2 = schedule(timedelta(seconds=interval))
+        m2 = self.create_model_interval(s2, enabled=True)
+        m2.last_run_at = self.app.now() - timedelta(seconds=interval + 1)
+        m2.save()
+        m2.refresh_from_db()
+
+        e1 = EntryTrackSave(m1, self.app)
+        # because the disabled task e1 runs first, e2 will never be executed
+        e2 = EntryTrackSave(m2, self.app)
+
+        s = self.Scheduler(app=self.app)
+        s.schedule.clear()
+        s.schedule[e1.name] = e1
+        s.schedule[e2.name] = e2
+
+        tried = set()
+        for _ in range(len(s.schedule) * 8):
+            tick_interval = s.tick()
+            if tick_interval and tick_interval > 0.0:
+                tried.add(s._heap[0].entry.name)
+                time.sleep(tick_interval)
+                if s.should_sync():
+                    s.sync()
+        assert len(tried) == 1 and tried == set([e1.name])
+
 
 @pytest.mark.django_db()
 class test_models(SchedulerCase):