feat: add concurrency checks for POS orders and payments using write_date verification

models/pos_order.py

@@ -142,6 +142,18 @@ class PosOrder(models.Model):
                 # Use PostgreSQL transaction-level advisory lock
                 self.env.cr.execute("SELECT pg_advisory_xact_lock(hashtext(%s))", (uuid,))
 
+                # Check for concurrent updates that occurred before we acquired the lock
+                with self.env.registry.cursor() as fresh_cr:
+                    fresh_cr.execute("SELECT write_date FROM pos_order WHERE uuid = %s", (uuid,))
+                    fresh_res = fresh_cr.fetchone()
+
+                self.env.cr.execute("SELECT write_date FROM pos_order WHERE uuid = %s", (uuid,))
+                curr_res = self.env.cr.fetchone()
+
+                if fresh_res != curr_res:
+                    from odoo.exceptions import ConcurrencyError
+                    raise ConcurrencyError("Concurrent update detected for order uuid %s. Retrying transaction." % uuid)
+
         return super(PosOrder, self).sync_from_ui(orders)
 
 

models/pos_payment.py

@@ -18,7 +18,20 @@ class PosPayment(models.Model):
         for uuid in sorted_uuids:
             self.env.cr.execute("SELECT pg_advisory_xact_lock(hashtext(%s))", (uuid,))
 
-        # 3. Check which payments already exist in the database
+        # 3. Check for concurrent updates/creations of these payments
+        if sorted_uuids:
+            with self.env.registry.cursor() as fresh_cr:
+                fresh_cr.execute("SELECT uuid, write_date FROM pos_payment WHERE uuid IN %s", (tuple(sorted_uuids),))
+                fresh_res = dict(fresh_cr.fetchall())
+
+            self.env.cr.execute("SELECT uuid, write_date FROM pos_payment WHERE uuid IN %s", (tuple(sorted_uuids),))
+            curr_res = dict(self.env.cr.fetchall())
+
+            if fresh_res != curr_res:
+                from odoo.exceptions import ConcurrencyError
+                raise ConcurrencyError("Concurrent update/insertion detected for payment uuids. Retrying transaction.")
+
+        # 4. Check which payments already exist in the database using the current snapshot
         existing_payments_map = {}
         if sorted_uuids:
             existing_payments = self.search([('uuid', 'in', sorted_uuids)])