fix(events): keep registration status reads nonblocking

apps/events/api/views.py

@@ -39,7 +39,7 @@ from apps.events.models import Event, Registration
 from apps.events.checkout import (
     CHECKOUT_TIMEOUT,
     cancel_event_checkouts,
-    expire_stale_registration_checkouts,
+    expire_user_registration_checkouts,
     mark_checkout_cancelled,
     queue_checkout_reconciliation,
 )
@@ -599,8 +599,13 @@ def register_for_event(
     """Register current user for an event"""
     user = request.auth
     now = timezone.now()
-    expire_stale_registration_checkouts(now=now, event_id=event_id)
-
+    with transaction.atomic():
+        event = get_object_or_404(
+            Event.objects.select_for_update(),
+            id=event_id,
+            is_deleted=False,
+        )
+        expire_user_registration_checkouts(event=event, user=user, now=now)
     with transaction.atomic():
         event = get_object_or_404(
             Event.objects.select_for_update(),
@@ -937,10 +942,6 @@ def is_registered(request, event_id: int):
         .order_by("-registered_at", "-id")
         .first()
     )
-    if registration and registration.status == Registration.StatusChoices.PENDING and registration.checkout_expires_at and registration.checkout_expires_at <= now:
-        expire_stale_registration_checkouts(now=now, event_id=event_id)
-        registration.refresh_from_db()
-
     payment = None
     if registration:
         payment = registration.payments.order_by("-created_at", "-id").first()
@@ -1154,7 +1155,6 @@ def registration_hub_status(
         lookup = {"pk": int(slug)} if slug.isdecimal() else {"slug": slug}
         event = get_object_or_404(Event, is_deleted=False, **lookup)
     now = timezone.now()
-    expire_stale_registration_checkouts(now=now, event_id=event.id)
     registration, payment = _registration_hub_records(
         event,
         request.auth,