Issue #11675: Zero-out newly-created multiprocessing.[Raw]Array objects.
diff --git a/Lib/multiprocessing/sharedctypes.py b/Lib/multiprocessing/sharedctypes.py
index 2430be7..1eb044d 100644
--- a/Lib/multiprocessing/sharedctypes.py
+++ b/Lib/multiprocessing/sharedctypes.py
@@ -80,7 +80,9 @@
type_ = typecode_to_type.get(typecode_or_type, typecode_or_type)
if isinstance(size_or_initializer, (int, long)):
type_ = type_ * size_or_initializer
- return _new_value(type_)
+ obj = _new_value(type_)
+ ctypes.memset(ctypes.addressof(obj), 0, ctypes.sizeof(obj))
+ return obj
else:
type_ = type_ * len(size_or_initializer)
result = _new_value(type_)
diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py
index bdfc171..0df2f78 100644
--- a/Lib/test/test_multiprocessing.py
+++ b/Lib/test/test_multiprocessing.py
@@ -914,6 +914,21 @@
self.assertEqual(list(arr[:]), seq)
@unittest.skipIf(c_int is None, "requires _ctypes")
+ def test_array_from_size(self):
+ size = 10
+ # Test for zeroing (see issue #11675).
+ # The repetition below strengthens the test by increasing the chances
+ # of previously allocated non-zero memory being used for the new array
+ # on the 2nd and 3rd loops.
+ for _ in range(3):
+ arr = self.Array('i', size)
+ self.assertEqual(len(arr), size)
+ self.assertEqual(list(arr), [0] * size)
+ arr[:] = range(10)
+ self.assertEqual(list(arr), range(10))
+ del arr
+
+ @unittest.skipIf(c_int is None, "requires _ctypes")
def test_rawarray(self):
self.test_array(raw=True)
diff --git a/Misc/NEWS b/Misc/NEWS
index 4447289..d435890 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -9,6 +9,10 @@
Core and Builtins
-----------------
+- Issue #11675: multiprocessing.[Raw]Array objects created from an integer size
+ are now zeroed on creation. This matches the behaviour specified by the
+ documentation.
+
- Issue #11450: Don't truncate hg version info in Py_GetBuildInfo() when
there are many tags (e.g. when using mq). Patch by Nadeem Vawda.