bpo-26836: Add os.memfd_create() (#13567)

* bpo-26836: Add os.memfd_create()

* Use the glibc wrapper for memfd_create()

Co-Authored-By: Christian Heimes <christian@python.org>

* Fix deletions caused by autoreconf.

* Use MFD_CLOEXEC as the default value for *flags*.

* Add memset_s to configure.ac.

* Revert memset_s changes.

* Apply the requested changes.

* Tweak the docs.

1 files changed, 16 insertions, 0 deletions

diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 353b9a5..820c99c 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -3122,6 +3122,22 @@ class TermsizeTests(unittest.TestCase):
         self.assertEqual(expected, actual)
 
 
+@unittest.skipUnless(hasattr(os, 'memfd_create'), 'requires os.memfd_create')
+class MemfdCreateTests(unittest.TestCase):
+    def test_memfd_create(self):
+        fd = os.memfd_create("Hi", os.MFD_CLOEXEC)
+        self.assertNotEqual(fd, -1)
+        self.addCleanup(os.close, fd)
+        self.assertFalse(os.get_inheritable(fd))
+        with open(fd, "wb", closefd=False) as f:
+            f.write(b'memfd_create')
+            self.assertEqual(f.tell(), 12)
+
+        fd2 = os.memfd_create("Hi")
+        self.addCleanup(os.close, fd2)
+        self.assertFalse(os.get_inheritable(fd2))
+
+
 class OSErrorTests(unittest.TestCase):
     def setUp(self):
         class Str(str):