Ticket #9479: 9479-r10858.2.diff

new file tests/regressiontests/delete_regress/__init__.py

@@ +1 @@
+

new file tests/regressiontests/delete_regress/models.py

@@ +1 @@
+from django.conf import settings
+from django.db import models, backend, connection, transaction
+from django.db.models import sql, query
+from django.test import TransactionTestCase
+
+class Book(models.Model):
+    pagecount = models.IntegerField()
+
+if settings.DATABASE_ENGINE != 'sqlite3':
+    class DeleteLockingTest(TransactionTestCase):
+        def setUp(self):
+            # Create a second connection to the database
+            self.conn2 = backend.DatabaseWrapper({
+                'DATABASE_HOST': settings.DATABASE_HOST,
+                'DATABASE_NAME': settings.DATABASE_NAME,
+                'DATABASE_OPTIONS': settings.DATABASE_OPTIONS,
+                'DATABASE_PASSWORD': settings.DATABASE_PASSWORD,
+                'DATABASE_PORT': settings.DATABASE_PORT,
+                'DATABASE_USER': settings.DATABASE_USER,
+                'TIME_ZONE': settings.TIME_ZONE,
+            })
+
+            # Put both DB connections into managed transaction mode
+            transaction.enter_transaction_management(True)
+            self.conn2._enter_transaction_management(True)
+
+        def tearDown(self):
+            # Close down the second connection.
+            self.conn2.close()
+
+        def test_concurrent_delete(self):
+            "Deletes on concurrent transactions don't collide and lock the database"
+
+            # Create some dummy data
+            b1 = Book(id=1, pagecount=100)
+            b2 = Book(id=2, pagecount=200)
+            b1.save()
+            b2.save()
+
+            transaction.commit()
+
+            self.assertEquals(2, Book.objects.count())
+
+            # Now with connection 1 committed, delete something using connection 2
+            # This causes an infinite loop under MySQL InnoDB if we don't keep track
+            # of already deleted objects.
+            cursor2 = self.conn2.cursor()
+            q = sql.Query(Book, self.conn2)
+            query.QuerySet(Book, q).filter(pk=1).delete()
+
+            self.assertEquals(1, Book.objects.count())