Sync with upstream changes

[GoogleCodeExporter]

The concurrent.futures module in cpython has had some changes since this 
backport was released; it would be good to sync up with cpython 3.3.  I'm 
particularly interested in this change:
  http://hg.python.org/cpython/annotate/4390d6939a56/Lib/concurrent/futures/thread.py#130
which prevents a 100ms delay when shutting down a ThreadPoolExecutor.

Original issue reported on code.google.com by ben.darn...@gmail.com on 23 May 2013 at 3:28

[GoogleCodeExporter]

would be great to sync with upstream, I am looking for this one:

http://hg.python.org/cpython/rev/6d6099f7fe89
Issue #9205: concurrent.futures.ProcessPoolExecutor now detects killed

Original comment by taylorba...@gmail.com on 1 Oct 2013 at 9:58

[GoogleCodeExporter]

Detecting dead processes is really important since otherwise things just hang 
indefinitely.  There isn't a workaround (eg trying to examine 
ProcessPoolExecutor internal state).

Original comment by rogerbinns on 11 Apr 2014 at 5:09

[GoogleCodeExporter]

Agreed, the lack of support for "Detecting dead processes" means that I can't 
use the backport in a production environment.

Original comment by jtobe...@gmail.com on 1 Jul 2014 at 3:28

[harlowja]

:+1: to this, there have been some changes that have been flushing through upstream to fix bugs that would be great to have incorporated here (if they haven't already been).

• https://bugs.python.org/issue9205
• https://bugs.python.org/issue16284
• https://bugs.python.org/issue22393
• https://bugs.python.org/issue21362
• others?

[agronholm]

Issue 21362 is the only one that is actually fixable -- the rest have either been fixed already or unfixable due to upstream code using py3 specific features.

[agronholm]

I'm closing this as wontfix because 21362 has been fixed here already and the rest are not fixable.