From 26660401c0c7b0816392bb32bdb69eb75a3b17df Mon Sep 17 00:00:00 2001
From: "Gregory P. Smith" <greg@mad-scientist.com>
Date: Sun, 1 Jun 2008 23:44:46 +0000
Subject: [PATCH] Backport r62724 from trunk. Fixes issue 2791.
subprocess.Popen.communicate now closes its stdout and stderr fds as soon as
it is finished with them.
---
Lib/subprocess.py | 2 ++
Lib/test/test_subprocess.py | 16 ++++++++++++++++
Misc/NEWS | 4 ++++
3 files changed, 22 insertions(+)
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 094ca1ba88..31c02df7af 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -660,8 +660,10 @@ class Popen(object):
self.stdin.close()
elif self.stdout:
stdout = self.stdout.read()
+ self.stdout.close()
elif self.stderr:
stderr = self.stderr.read()
+ self.stderr.close()
self.wait()
return (stdout, stderr)
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index c2db6fab20..123d4a0218 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -304,6 +304,22 @@ class ProcessTestCase(unittest.TestCase):
self.assertEqual(remove_stderr_debug_decorations(stderr),
"pineapple")
+ # This test is Linux specific for simplicity to at least have
+ # some coverage. It is not a platform specific bug.
+ if os.path.isdir('/proc/%d/fd' % os.getpid()):
+ # Test for the fd leak reported in http://bugs.python.org/issue2791.
+ def test_communicate_pipe_fd_leak(self):
+ fd_directory = '/proc/%d/fd' % os.getpid()
+ num_fds_before_popen = len(os.listdir(fd_directory))
+ p = subprocess.Popen([sys.executable, '-c', 'print()'],
+ stdout=subprocess.PIPE)
+ p.communicate()
+ num_fds_after_communicate = len(os.listdir(fd_directory))
+ del p
+ num_fds_after_destruction = len(os.listdir(fd_directory))
+ self.assertEqual(num_fds_before_popen, num_fds_after_destruction)
+ self.assertEqual(num_fds_before_popen, num_fds_after_communicate)
+
def test_communicate_returns(self):
# communicate() should return None if no redirection is active
p = subprocess.Popen([sys.executable, "-c",
diff --git a/Misc/NEWS b/Misc/NEWS
index 2a60b051cb..4eb8a80704 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -82,6 +82,10 @@ Library
- Bug #1433694: minidom's .normalize() failed to set .nextSibling for
last child element.
+- Issue #2791: subprocess.Popen.communicate explicitly closes its
+ stdout and stderr fds rather than leaving them open until the
+ instance is destroyed.
+
Extension Modules
-----------------
--
2.40.0