* multiprocessing: open file with closefd=False to avoid ResourceWarning
* _test_multiprocessing: open file with O_EXCL to detect bugs in tests (if a
  previous test forgot to remove TESTFN)
* test_sys_exit(): remove TESTFN after each loop iteration

Initial patch written by Serhiy Storchaka.
This commit is contained in:
Victor Stinner 2016-03-25 09:29:50 +01:00
parent 540a81c720
commit 8a20851010
5 changed files with 39 additions and 19 deletions

View File

@ -2689,7 +2689,7 @@ Beware of replacing :data:`sys.stdin` with a "file like object"
in issues with processes-in-processes. This has been changed to::
sys.stdin.close()
sys.stdin = open(os.devnull)
sys.stdin = open(os.open(os.devnull, os.O_RDONLY), closefd=False)
Which solves the fundamental issue of processes colliding with each other
resulting in a bad file descriptor error, but introduces a potential danger

View File

@ -147,13 +147,7 @@ def main(listener_fd, alive_r, preload, main_path=None, sys_path=None):
except ImportError:
pass
# close sys.stdin
if sys.stdin is not None:
try:
sys.stdin.close()
sys.stdin = open(os.devnull)
except (OSError, ValueError):
pass
util._close_stdin()
# ignoring SIGCHLD means no need to reap zombie processes
handler = signal.signal(signal.SIGCHLD, signal.SIG_IGN)

View File

@ -234,12 +234,7 @@ class BaseProcess(object):
context._force_start_method(self._start_method)
_process_counter = itertools.count(1)
_children = set()
if sys.stdin is not None:
try:
sys.stdin.close()
sys.stdin = open(os.devnull)
except (OSError, ValueError):
pass
util._close_stdin()
old_process = _current_process
_current_process = self
try:

View File

@ -9,6 +9,7 @@
import os
import itertools
import sys
import weakref
import atexit
import threading # we want threading to install it's
@ -356,6 +357,28 @@ def close_all_fds_except(fds):
assert fds[-1] == MAXFD, 'fd too large'
for i in range(len(fds) - 1):
os.closerange(fds[i]+1, fds[i+1])
#
# Close sys.stdin and replace stdin with os.devnull
#
def _close_stdin():
if sys.stdin is None:
return
try:
sys.stdin.close()
except (OSError, ValueError):
pass
try:
fd = os.open(os.devnull, os.O_RDONLY)
try:
sys.stdin = open(fd, closefd=False)
except:
os.close(fd)
raise
except (OSError, ValueError):
pass
#
# Start a program with only specified fds kept open

View File

@ -455,13 +455,15 @@ class _TestSubclassingProcess(BaseTestCase):
@classmethod
def _test_stderr_flush(cls, testfn):
sys.stderr = open(testfn, 'w')
fd = os.open(testfn, os.O_WRONLY | os.O_CREAT | os.O_EXCL)
sys.stderr = open(fd, 'w', closefd=False)
1/0 # MARKER
@classmethod
def _test_sys_exit(cls, reason, testfn):
sys.stderr = open(testfn, 'w')
fd = os.open(testfn, os.O_WRONLY | os.O_CREAT | os.O_EXCL)
sys.stderr = open(fd, 'w', closefd=False)
sys.exit(reason)
def test_sys_exit(self):
@ -472,15 +474,21 @@ class _TestSubclassingProcess(BaseTestCase):
testfn = test.support.TESTFN
self.addCleanup(test.support.unlink, testfn)
for reason, code in (([1, 2, 3], 1), ('ignore this', 1)):
for reason in (
[1, 2, 3],
'ignore this',
):
p = self.Process(target=self._test_sys_exit, args=(reason, testfn))
p.daemon = True
p.start()
p.join(5)
self.assertEqual(p.exitcode, code)
self.assertEqual(p.exitcode, 1)
with open(testfn, 'r') as f:
self.assertEqual(f.read().rstrip(), str(reason))
content = f.read()
self.assertEqual(content.rstrip(), str(reason))
os.unlink(testfn)
for reason in (True, False, 8):
p = self.Process(target=sys.exit, args=(reason,))