From: Georg Brandl <georg@python.org>
Date: Sat, 14 Feb 2009 17:01:36 +0000 (+0000)
Subject: #5179: don't leak PIPE fds when child execution fails.
X-Git-Tag: v2.7a1~2020
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f3715d2fc72e191c58c76e1eba92f6bc0a5a0e9d;p=python

#5179: don't leak PIPE fds when child execution fails.
---

diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 309f5d4d83..d91fbee34c 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -1151,6 +1151,9 @@ class Popen(object):
             if data != "":
                 os.waitpid(self.pid, 0)
                 child_exception = pickle.loads(data)
+                for fd in (p2cwrite, c2pread, errread):
+                    if fd is not None:
+                        os.close(fd)
                 raise child_exception
 
 
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index ae8e88877f..0ddac3dcb9 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -520,6 +520,22 @@ class ProcessTestCase(unittest.TestCase):
         else:
             self.fail("Expected TypeError")
 
+    def test_leaking_fds_on_error(self):
+        # see bug #5179: Popen leaks file descriptors to PIPEs if
+        # the child fails to execute; this will eventually exhaust
+        # the maximum number of open fds. 1024 seems a very common
+        # value for that limit, but Windows has 2048, so we loop
+        # 1024 times (each call leaked two fds).
+        for i in range(1024):
+            try:
+                subprocess.Popen(['nonexisting_i_hope'],
+                                 stdout=subprocess.PIPE,
+                                 stderr=subprocess.PIPE)
+            # Windows raises IOError
+            except (IOError, OSError), err:
+                if err.errno != 2:  # ignore "no such file"
+                    raise
+
     #
     # POSIX tests
     #