Migrate timer status to enum instead of int

django_q/cluster.py

@@ -31,6 +31,7 @@ from django_q.conf import (
     psutil,
     setproctitle,
 )
+from django_q.enums import TimerStatus
 from django_q.humanhash import humanize
 from django_q.monitor import monitor
 from django_q.pusher import pusher
@@ -234,7 +235,11 @@ class Sentinel:
 
     def spawn_worker(self):
         self.spawn_process(
-            worker, self.task_queue, self.result_queue, Value("f", -1), self.timeout
+            worker,
+            self.task_queue,
+            self.result_queue,
+            Value("f", TimerStatus.IDLE),
+            self.timeout,
         )
 
     def spawn_monitor(self) -> Process:
@@ -271,7 +276,7 @@ class Sentinel:
 
             self.pool.remove(process)
             self.spawn_worker()
-            if process.timer.value == 0:
+            if process.timer.value == TimerStatus.TIMEOUT:
                 # only need to terminate on timeout, otherwise we risk destabilizing
                 # the queues
                 task_name = ""
@@ -296,7 +301,7 @@ class Sentinel:
                         "name": process.name
                     }
                 logger.critical(msg)
-            elif int(process.timer.value) == -2:
+            elif int(process.timer.value) == TimerStatus.RECYCLED:
                 logger.info(_("recycled worker %(name)s") % {"name": process.name})
             else:
                 logger.critical(
@@ -348,11 +353,11 @@ class Sentinel:
             for p in self.pool:
                 with p.timer.get_lock():
                     # Are you alive?
-                    if not p.is_alive() or p.timer.value == 0:
+                    if not p.is_alive() or p.timer.value == TimerStatus.TIMEOUT:
                         self.reincarnate(p)
                         continue
                     # Decrement timer if work is being done
-                    if p.timer.value > 0:
+                    if p.timer.value > TimerStatus.TIMEOUT:
                         p.timer.value -= cycle
             # Check Monitor
             if not self.monitor.is_alive():

django_q/enums.py

@@ -0,0 +1,14 @@
+from enum import IntEnum
+
+
+class TimerStatus(IntEnum):
+    """
+    Sentinel values for the countdown timer a worker shares with the sentinel.
+
+    Any positive value is the number of seconds left before the sentinel
+    considers the task timed out and reincarnates the worker.
+    """
+
+    TIMEOUT = 0  # task timed out, the worker has to be terminated
+    IDLE = -1  # waiting for work, or working without a timeout
+    RECYCLED = -2  # recycle limit reached, the worker stopped on its own

django_q/tests/test_cached.py

@@ -6,6 +6,7 @@ import pytest
 
 from django_q.brokers import get_broker
 from django_q.conf import Conf
+from django_q.enums import TimerStatus
 from django_q.monitor import monitor
 from django_q.pusher import pusher
 from django_q.queues import Queue
@@ -67,7 +68,7 @@ def test_cached(broker):
     assert task_queue.qsize() == task_count
     task_queue.put("STOP")
     result_queue = Queue()
-    worker(task_queue, result_queue, Value("f", -1))
+    worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
     assert result_queue.qsize() == task_count
     result_queue.put("STOP")
     monitor(result_queue)

django_q/tests/test_cluster.py

@@ -15,6 +15,7 @@ from django.utils import timezone
 from django_q.brokers import Broker, get_broker
 from django_q.cluster import Cluster, Sentinel
 from django_q.conf import Conf
+from django_q.enums import TimerStatus
 from django_q.humanhash import DEFAULT_WORDLIST, uuid
 from django_q.models import Success, Task
 from django_q.monitor import monitor, save_task
@@ -245,7 +246,7 @@ def test_cluster(broker):
     assert queue_size(broker=broker) == 0
     # Test work
     task_queue.put("STOP")
-    worker(task_queue, result_queue, Value("f", -1))
+    worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
     assert task_queue.qsize() == 0
     assert result_queue.qsize() == 1
     # Test monitor
@@ -272,7 +273,7 @@ def test_results(broker):
     pusher(task_queue, stop_event, broker=broker)
     task_queue.put("STOP")
     result_queue = Queue()
-    worker(task_queue, result_queue, Value("f", -1))
+    worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
     result_queue.put("STOP")
     monitor(result_queue)
 
@@ -372,7 +373,7 @@ def test_enqueue(broker, admin_user):
     assert fetch_group("test_j", count=2, wait=10) is None
     # let a worker handle them
     result_queue = Queue()
-    worker(task_queue, result_queue, Value("f", -1))
+    worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
     assert result_queue.qsize() == task_count
     result_queue.put("STOP")
     # store the results
@@ -541,7 +542,7 @@ def test_recycle(broker, monkeypatch, django_assert_num_queries):
     pusher(task_queue, stop_event, broker=broker)
     pusher(task_queue, stop_event, broker=broker)
     # worker should exit on recycle
-    worker(task_queue, result_queue, Value("f", -1))
+    worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
     # check if the work has been done
     assert result_queue.qsize() == 2
     # save_limit test
@@ -573,7 +574,7 @@ def test_save_limit_per_func(broker, monkeypatch):
     threading.Timer(3, stop_event.set).start()
     for i in range(3):
         pusher(task_queue, stop_event, broker=broker)
-    worker(task_queue, result_queue, Value("f", -1))
+    worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
     s = Sentinel(stop_event, start_event, cluster_id=cluster_id, broker=broker)
     assert start_event.is_set()
     assert s.status() == Conf.STOPPED
@@ -618,7 +619,7 @@ def test_max_rss(broker, monkeypatch):
     # push the task
     pusher(task_queue, stop_event, broker=broker)
     # worker should exit on recycle
-    worker(task_queue, result_queue, Value("f", -1))
+    worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
     # check if the work has been done
     assert result_queue.qsize() == 1
     # save_limit test
@@ -654,7 +655,7 @@ def test_bad_secret(broker, monkeypatch):
     worker(
         task_queue,
         result_queue,
-        Value("f", -1),
+        Value("f", TimerStatus.IDLE),
     )
     assert result_queue.qsize() == 0
     broker.delete_queue()
@@ -838,7 +839,7 @@ class TestSignals:
         event.set()
         pusher(task_queue, event, broker=broker)
         task_queue.put("STOP")
-        worker(task_queue, result_queue, Value("f", -1))
+        worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
         result_queue.put("STOP")
         monitor(result_queue, broker)
         broker.delete_queue()
@@ -867,7 +868,7 @@ class TestSignals:
         event.set()
         pusher(task_queue, event, broker=broker)
         task_queue.put("STOP")
-        worker(task_queue, result_queue, Value("f", -1))
+        worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
         result_queue.put("STOP")
         monitor(result_queue, broker)
         broker.delete_queue()
@@ -896,7 +897,7 @@ class TestSignals:
         event.set()
         pusher(task_queue, event, broker=broker)
         task_queue.put("STOP")
-        worker(task_queue, result_queue, Value("f", -1))
+        worker(task_queue, result_queue, Value("f", TimerStatus.IDLE))
         result_queue.put("STOP")
         monitor(result_queue, broker)
         broker.delete_queue()

django_q/tests/test_scheduler.py

@@ -13,6 +13,7 @@ from django.utils.timezone import is_naive
 
 from django_q.brokers import Broker, get_broker
 from django_q.conf import Conf
+from django_q.enums import TimerStatus
 from django_q.monitor import monitor
 from django_q.pusher import pusher
 from django_q.queues import Queue
@@ -222,7 +223,7 @@ def test_scheduler(broker, monkeypatch):
     task_queue.put("STOP")
     # let a worker handle them
     result_queue = Queue()
-    worker(task_queue, result_queue, Value("b", -1))
+    worker(task_queue, result_queue, Value("b", TimerStatus.IDLE))
     assert result_queue.qsize() == 1
     result_queue.put("STOP")
     # store the results

django_q/worker.py

@@ -17,6 +17,7 @@ except core.exceptions.AppRegistryNotReady:
     django.setup()
 
 from django_q.conf import Conf, error_reporter, logger, resource, setproctitle
+from django_q.enums import TimerStatus
 from django_q.exceptions import TimeoutException
 from django_q.signals import post_execute_in_worker, post_spawn, pre_execute
 from django_q.timeout import TimeoutHandler
@@ -54,11 +55,11 @@ def worker(
         setproctitle.setproctitle(f"qcluster {proc_name} idle")
     task_count = 0
     if timeout is None:
-        timeout = -1
+        timeout = TimerStatus.IDLE
     # Start reading the task queue
     for task in iter(task_queue.get, "STOP"):
         result = None
-        timer.value = -1  # Idle
+        timer.value = TimerStatus.IDLE
         task_count += 1
         f = task["func"]
 
@@ -92,7 +93,7 @@ def worker(
         pre_execute.send(sender="django_q", func=f, task=task)
         # execute the payload
         timer.value = timer_value  # Busy
-        if timer.value != -1:
+        if timer.value != TimerStatus.IDLE:
             timer.value += 3  # Add buffer so that guard doesn't kill the process on timeout before it gets processed
 
         timeout_error = False
@@ -122,15 +123,15 @@ def worker(
             result_queue.put(task)
             if timeout_error:
                 # force destroy process due to timeout
-                timer.value = 0
+                timer.value = TimerStatus.TIMEOUT
                 break
 
-            timer.value = -1  # Idle
+            timer.value = TimerStatus.IDLE
             if setproctitle:
                 setproctitle.setproctitle(f"qcluster {proc_name} idle")
             # Recycle
             if task_count == Conf.RECYCLE or rss_check():
-                timer.value = -2  # Recycled
+                timer.value = TimerStatus.RECYCLED
                 break
     logger.info(_("%(proc_name)s stopped doing work") % {"proc_name": proc_name})