[New-bugs-announce] [issue15756] subprocess.poll() does not handle errno.ECHILD "No child processes"

[Todd Whiteman]

New submission from Todd Whiteman:

In the case of a "errno.ECHILD" exception - Python's subprocess module misses the fact that the process has already ended.

The following code will wait indefinitely, even though the launched process is quickly ended:

import subprocess, signal
signal.signal(signal.SIGCLD, signal.SIG_IGN)
p = subprocess.Popen(['echo','foo'])
while p.poll() is None:
   pass # wait for the process to exit

Note: This is the exact same issue as issue1731717, but applying to the subprocess.poll() method instead of the subprocess.wait() method.

----------
components: Library (Lib)
messages: 168798
nosy: twhitema
priority: normal
severity: normal
status: open
title: subprocess.poll() does not handle errno.ECHILD "No child processes"
type: behavior
versions: Python 2.6, Python 2.7, Python 3.1, Python 3.2, Python 3.3, Python 3.4

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue15756>
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