From 8acfe2b62c88ffb9910ebc7d51d6015c09e71588 Mon Sep 17 00:00:00 2001 From: Antoine Pitrou Date: Fri, 25 Nov 2011 21:28:15 +0100 Subject: Issue #12856: Ensure child processes do not inherit the parent's random seed for filename generation in the tempfile module. Patch by Brian Harring. --- Lib/test/test_tempfile.py | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'Lib/test/test_tempfile.py') diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py index f7f5bdadbd..50cf3b49cb 100644 --- a/Lib/test/test_tempfile.py +++ b/Lib/test/test_tempfile.py @@ -1,6 +1,7 @@ # tempfile.py unit tests. import tempfile import os +import signal import sys import re import warnings @@ -135,6 +136,37 @@ class test__RandomNameSequence(TC): except: self.failOnException("iteration") + @unittest.skipUnless(hasattr(os, 'fork'), + "os.fork is required for this test") + def test_process_awareness(self): + # ensure that the random source differs between + # child and parent. + read_fd, write_fd = os.pipe() + pid = None + try: + pid = os.fork() + if not pid: + os.close(read_fd) + os.write(write_fd, next(self.r).encode("ascii")) + os.close(write_fd) + # bypass the normal exit handlers- leave those to + # the parent. + os._exit(0) + parent_value = next(self.r) + child_value = os.read(read_fd, len(parent_value)).decode("ascii") + finally: + if pid: + # best effort to ensure the process can't bleed out + # via any bugs above + try: + os.kill(pid, signal.SIGKILL) + except EnvironmentError: + pass + os.close(read_fd) + os.close(write_fd) + self.assertNotEqual(child_value, parent_value) + + test_classes.append(test__RandomNameSequence) -- cgit v1.2.1