[Python-checkins] cpython (merge 3.2 -> 3.2): merge heads
benjamin.peterson
python-checkins at python.org
Thu Aug 18 20:55:49 CEST 2011
http://hg.python.org/cpython/rev/9887d8127b10
changeset: 71907:9887d8127b10
branch: 3.2
parent: 71905:deb87aaf8ee9
parent: 71903:8ca7f109ce79
user: Benjamin Peterson <benjamin at python.org>
date: Thu Aug 18 13:54:16 2011 -0500
summary:
merge heads
files:
Lib/subprocess.py | 7 ++-
Lib/test/test_subprocess.py | 58 +++++++++++++++++++++++++
Misc/NEWS | 5 ++
3 files changed, 69 insertions(+), 1 deletions(-)
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -429,12 +429,16 @@
except:
MAXFD = 256
+# This lists holds Popen instances for which the underlying process had not
+# exited at the time its __del__ method got called: those processes are wait()ed
+# for synchronously from _cleanup() when a new Popen object is created, to avoid
+# zombie processes.
_active = []
def _cleanup():
for inst in _active[:]:
res = inst._internal_poll(_deadstate=sys.maxsize)
- if res is not None and res >= 0:
+ if res is not None:
try:
_active.remove(inst)
except ValueError:
@@ -1191,6 +1195,7 @@
errread, errwrite,
errpipe_read, errpipe_write,
restore_signals, start_new_session, preexec_fn)
+ self._child_created = True
else:
# Pure Python implementation: It is not thread safe.
# This implementation may deadlock in the child if your
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -1394,6 +1394,64 @@
finally:
p.wait()
+ def test_zombie_fast_process_del(self):
+ # Issue #12650: on Unix, if Popen.__del__() was called before the
+ # process exited, it wouldn't be added to subprocess._active, and would
+ # remain a zombie.
+ # spawn a Popen, and delete its reference before it exits
+ p = subprocess.Popen([sys.executable, "-c",
+ 'import sys, time;'
+ 'time.sleep(0.2)'],
+ stdout=subprocess.PIPE,
+ stderr=subprocess.PIPE)
+ ident = id(p)
+ pid = p.pid
+ del p
+ # check that p is in the active processes list
+ self.assertIn(ident, [id(o) for o in subprocess._active])
+
+ # sleep a little to let the process exit, and create a new Popen: this
+ # should trigger the wait() of p
+ time.sleep(1)
+ with self.assertRaises(EnvironmentError) as c:
+ with subprocess.Popen(['nonexisting_i_hope'],
+ stdout=subprocess.PIPE,
+ stderr=subprocess.PIPE) as proc:
+ pass
+ # p should have been wait()ed on, and removed from the _active list
+ self.assertRaises(OSError, os.waitpid, pid, 0)
+ self.assertNotIn(ident, [id(o) for o in subprocess._active])
+
+ def test_leak_fast_process_del_killed(self):
+ # Issue #12650: on Unix, if Popen.__del__() was called before the
+ # process exited, and the process got killed by a signal, it would never
+ # be removed from subprocess._active, which triggered a FD and memory
+ # leak.
+ # spawn a Popen, delete its reference and kill it
+ p = subprocess.Popen([sys.executable, "-c",
+ 'import time;'
+ 'time.sleep(3)'],
+ stdout=subprocess.PIPE,
+ stderr=subprocess.PIPE)
+ ident = id(p)
+ pid = p.pid
+ del p
+ os.kill(pid, signal.SIGKILL)
+ # check that p is in the active processes list
+ self.assertIn(ident, [id(o) for o in subprocess._active])
+
+ # let some time for the process to exit, and create a new Popen: this
+ # should trigger the wait() of p
+ time.sleep(0.2)
+ with self.assertRaises(EnvironmentError) as c:
+ with subprocess.Popen(['nonexisting_i_hope'],
+ stdout=subprocess.PIPE,
+ stderr=subprocess.PIPE) as proc:
+ pass
+ # p should have been wait()ed on, and removed from the _active list
+ self.assertRaises(OSError, os.waitpid, pid, 0)
+ self.assertNotIn(ident, [id(o) for o in subprocess._active])
+
@unittest.skipUnless(mswindows, "Windows specific tests")
class Win32ProcessTestCase(BaseTestCase):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -13,6 +13,11 @@
- Issue #12266: Fix str.capitalize() to correctly uppercase/lowercase
titlecased and cased non-letter characters.
+Library
+-------
+
+- Issue #12650: Fix a race condition where a subprocess.Popen could leak
+ resources (FD/zombie) when killed at the wrong time.
What's New in Python 3.2.2?
===========================
--
Repository URL: http://hg.python.org/cpython
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