Fix PyUnknownFields memory leak (#7928)
Properly release internal data structure on deallocation.
Fix #7301
diff --git a/python/google/protobuf/internal/unknown_fields_test.py b/python/google/protobuf/internal/unknown_fields_test.py
index 277603d..a60b942 100755
--- a/python/google/protobuf/internal/unknown_fields_test.py
+++ b/python/google/protobuf/internal/unknown_fields_test.py
@@ -39,6 +39,12 @@
import unittest2 as unittest #PY26
except ImportError:
import unittest
+import sys
+try:
+ import tracemalloc
+except ImportError:
+ # Requires python 3.4+
+ pass
from google.protobuf import map_unittest_pb2
from google.protobuf import unittest_mset_pb2
from google.protobuf import unittest_pb2
@@ -312,6 +318,24 @@
self.assertIn('UnknownFields does not exist.',
str(context.exception))
+ @unittest.skipIf((sys.version_info.major, sys.version_info.minor) < (3, 4),
+ 'tracemalloc requires python 3.4+')
+ def testUnknownFieldsNoMemoryLeak(self):
+ # Call to UnknownFields must not leak memory
+ nb_leaks = 1234
+ def leaking_function():
+ for _ in range(nb_leaks):
+ self.empty_message.UnknownFields()
+ tracemalloc.start()
+ snapshot1 = tracemalloc.take_snapshot()
+ leaking_function()
+ snapshot2 = tracemalloc.take_snapshot()
+ top_stats = snapshot2.compare_to(snapshot1, 'lineno')
+ tracemalloc.stop()
+ # There's no easy way to look for a precise leak source.
+ # Rely on a "marker" count value while checking allocated memory.
+ self.assertEqual([], [x for x in top_stats if x.count_diff == nb_leaks])
+
def testSubUnknownFields(self):
message = unittest_pb2.TestAllTypes()
message.optionalgroup.a = 123
diff --git a/python/google/protobuf/pyext/unknown_fields.cc b/python/google/protobuf/pyext/unknown_fields.cc
index 8509213..deb86e6 100644
--- a/python/google/protobuf/pyext/unknown_fields.cc
+++ b/python/google/protobuf/pyext/unknown_fields.cc
@@ -142,6 +142,7 @@
}
Py_CLEAR(self->parent);
self->~PyUnknownFields();
+ Py_TYPE(pself)->tp_free(pself);
}
static PySequenceMethods SqMethods = {
