backport r60104 + r60111 from trunk.
- Issue #1336: fix a race condition in subprocess.Popen if the garbage
collector kicked in at the wrong time that would cause the process
to hang when the child wrote to stderr.
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 5b6fb18..094ca1b 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -358,6 +358,7 @@
import os
import types
import traceback
+import gc
# Exception classes used by this module.
class CalledProcessError(Exception):
@@ -1002,7 +1003,16 @@
errpipe_read, errpipe_write = os.pipe()
self._set_cloexec_flag(errpipe_write)
- self.pid = os.fork()
+ gc_was_enabled = gc.isenabled()
+ # Disable gc to avoid bug where gc -> file_dealloc ->
+ # write to stderr -> hang. http://bugs.python.org/issue1336
+ gc.disable()
+ try:
+ self.pid = os.fork()
+ except:
+ if gc_was_enabled:
+ gc.enable()
+ raise
self._child_created = True
if self.pid == 0:
# Child
@@ -1062,6 +1072,8 @@
os._exit(255)
# Parent
+ if gc_was_enabled:
+ gc.enable()
os.close(errpipe_write)
if p2cread and p2cwrite:
os.close(p2cread)