From: Victor Stinner <victor.stinner@gmail.com>
Date: Wed, 26 Jul 2017 00:32:42 +0000 (+0200)
Subject: bpo-31019: Fix multiprocessing.Process.is_alive() (#2875)
X-Git-Tag: v3.7.0a1~366
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=2db64823c20538a6cfc6033661fab5711d2d4585;p=thirdparty%2FPython%2Fcpython.git

bpo-31019: Fix multiprocessing.Process.is_alive() (#2875)

multiprocessing.Process.is_alive() now removes the process from the
_children set if the process completed.

The change prevents leaking "dangling" processes.
---

diff --git a/Lib/multiprocessing/process.py b/Lib/multiprocessing/process.py
index ce4ce43cfca6..8e500dc93dc6 100644
--- a/Lib/multiprocessing/process.py
+++ b/Lib/multiprocessing/process.py
@@ -148,10 +148,16 @@ class BaseProcess(object):
         if self is _current_process:
             return True
         assert self._parent_pid == os.getpid(), 'can only test a child process'
+
         if self._popen is None:
             return False
-        self._popen.poll()
-        return self._popen.returncode is None
+
+        returncode = self._popen.poll()
+        if returncode is None:
+            return True
+        else:
+            _children.discard(self)
+            return False
 
     def close(self):
         '''