diff --git a/tests/delete_regress/tests.py b/tests/delete_regress/tests.py index 0d33c9df9f..abfa248aea 100644 --- a/tests/delete_regress/tests.py +++ b/tests/delete_regress/tests.py @@ -15,46 +15,44 @@ from .models import (Book, Award, AwardNote, Person, Child, Toy, PlayedWith, # Can't run this test under SQLite, because you can't # get two connections to an in-memory database. +@skipUnlessDBFeature('test_db_allows_multiple_connections') class DeleteLockingTest(TransactionTestCase): available_apps = ['delete_regress'] def setUp(self): - transaction.set_autocommit(False) # Create a second connection to the default database new_connections = ConnectionHandler(settings.DATABASES) self.conn2 = new_connections[DEFAULT_DB_ALIAS] self.conn2.set_autocommit(False) def tearDown(self): - transaction.rollback() - transaction.set_autocommit(True) # Close down the second connection. self.conn2.rollback() self.conn2.close() - @skipUnlessDBFeature('test_db_allows_multiple_connections') def test_concurrent_delete(self): - "Deletes on concurrent transactions don't collide and lock the database. Regression for #9479" - - # Create some dummy data + """Concurrent deletes don't collide and lock the database (#9479).""" with transaction.atomic(): Book.objects.create(id=1, pagecount=100) Book.objects.create(id=2, pagecount=200) Book.objects.create(id=3, pagecount=300) - self.assertEqual(3, Book.objects.count()) - # Delete something using connection 2. - cursor2 = self.conn2.cursor() - cursor2.execute('DELETE from delete_regress_book WHERE id=1') - self.conn2._commit() - - # Now perform a queryset delete that covers the object - # deleted in connection 2. This causes an infinite loop - # under MySQL InnoDB unless we keep track of already - # deleted objects. with transaction.atomic(): + # Start a transaction on the main connection. + self.assertEqual(3, Book.objects.count()) + + # Delete something using another database connection. + with self.conn2.cursor() as cursor2: + cursor2.execute("DELETE from delete_regress_book WHERE id = 1") + self.conn2.commit() + + # In the same transaction on the main connection, perform a + # queryset delete that covers the object deleted with the other + # connection. This causes an infinite loop under MySQL InnoDB + # unless we keep track of already deleted objects. Book.objects.filter(pagecount__lt=250).delete() + self.assertEqual(1, Book.objects.count())