diff options
| -rw-r--r-- | Lib/test/test_os.py | 20 | ||||
| -rw-r--r-- | Misc/NEWS | 4 | ||||
| -rw-r--r-- | Python/random.c | 8 |
3 files changed, 30 insertions, 2 deletions
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py index eb13667..b7796b5 100644 --- a/Lib/test/test_os.py +++ b/Lib/test/test_os.py @@ -30,6 +30,11 @@ try: import threading except ImportError: threading = None +try: + import resource +except ImportError: + resource = None + from test.script_helper import assert_python_ok with warnings.catch_warnings(): @@ -1010,6 +1015,21 @@ class URandomTests(unittest.TestCase): data2 = self.get_urandom_subprocess(16) self.assertNotEqual(data1, data2) + @unittest.skipUnless(resource, "test requires the resource module") + def test_urandom_failure(self): + soft_limit, hard_limit = resource.getrlimit(resource.RLIMIT_NOFILE) + resource.setrlimit(resource.RLIMIT_NOFILE, (1, hard_limit)) + try: + with self.assertRaises(OSError) as cm: + os.urandom(16) + self.assertEqual(cm.exception.errno, errno.EMFILE) + finally: + # We restore the old limit as soon as possible. If doing it + # using addCleanup(), code running in between would fail + # creating any file descriptor. + resource.setrlimit(resource.RLIMIT_NOFILE, (soft_limit, hard_limit)) + + @contextlib.contextmanager def _execvpe_mockup(defpath=None): """ @@ -28,6 +28,10 @@ Core and Builtins Library ------- +- Issue #18756: Improve error reporting in os.urandom() when the failure + is due to something else than /dev/urandom not existing (for example, + exhausting the file descriptor limit). + - Issue #18673: Add O_TMPFILE to os module. O_TMPFILE requires Linux kernel 3.11 or newer. It's only defined on system with 3.11 uapi headers, too. diff --git a/Python/random.c b/Python/random.c index 1ad4c3d..709f980 100644 --- a/Python/random.c +++ b/Python/random.c @@ -138,8 +138,12 @@ dev_urandom_python(char *buffer, Py_ssize_t size) Py_END_ALLOW_THREADS if (fd < 0) { - PyErr_SetString(PyExc_NotImplementedError, - "/dev/urandom (or equivalent) not found"); + if (errno == ENOENT || errno == ENXIO || + errno == ENODEV || errno == EACCES) + PyErr_SetString(PyExc_NotImplementedError, + "/dev/urandom (or equivalent) not found"); + else + PyErr_SetFromErrno(PyExc_OSError); return -1; } |