fix(clock): dedup tasks lock bug removal

polylan_submitter/games/tasks.py

@@ -1,4 +1,5 @@
 from datetime import timedelta
+from uuid import uuid4
 
 from django.conf import settings
 from django.core.cache import cache
@@ -10,7 +11,9 @@ from .services.steam_store import refresh_steam_games
 # Set while a periodic refresh is queued, so there's only ever one loop running,
 # whatever the number of workers/containers trying to start it. It expires on
 # its own if the loop dies (worker killed mid-job, Redis queue flushed, ...),
-# letting the next schedule_steam_refresh() start a new one.
+# letting the next schedule_steam_refresh() start a new one. The guard holds the
+# loop id, so if it expires while the old loop is just late, the old one stops
+# at its next run (instead of 2 loops running side by side).
 STEAM_REFRESH_GUARD_KEY = "games:steam_refresh:scheduled"
 
 
@@ -25,28 +28,34 @@ def _guard_timeout() -> int:
 def schedule_steam_refresh() -> bool:
     """Start the periodic refresh loop right away, unless one is already queued.
     Safe to call from anywhere, any number of times."""
-    if not cache.add(STEAM_REFRESH_GUARD_KEY, 1, timeout=_guard_timeout()):
+    loop_id = uuid4().hex
+    if not cache.add(STEAM_REFRESH_GUARD_KEY, loop_id, timeout=_guard_timeout()):
         return False
 
-    refresh_steam_games_task.enqueue()
+    refresh_steam_games_task.enqueue(loop_id=loop_id)
     return True
 
 
 @task
 def refresh_steam_games_task(
-    game_ids: list[int] | None = None, reschedule: bool = True
+    game_ids: list[int] | None = None, loop_id: str | None = None
 ):
     """Refresh Steam store info, then re-enqueue itself every
     STEAM_STORE_REFRESH_MINUTES (same self-rescheduling idea as
     sync_event_game_scopes_task, no external scheduler needed).
 
-    reschedule=False is a one-off run (e.g. the admin action) that leaves the
-    periodic loop alone."""
+    Without loop_id it's a one-off run (e.g. the admin action) that leaves the
+    periodic loop alone. With loop_id, it only continues while the guard still
+    holds this loop_id."""
+    if loop_id is not None and cache.get(STEAM_REFRESH_GUARD_KEY) != loop_id:
+        # Another loop owns the guard (or it expired), stop this one
+        return
+
     try:
         refresh_steam_games(game_ids)
     finally:
-        if reschedule:
-            cache.set(STEAM_REFRESH_GUARD_KEY, 1, timeout=_guard_timeout())
+        if loop_id is not None:
+            cache.set(STEAM_REFRESH_GUARD_KEY, loop_id, timeout=_guard_timeout())
             refresh_steam_games_task.using(
                 run_after=timezone.now() + steam_refresh_interval()
-            ).enqueue()
+            ).enqueue(loop_id=loop_id)