Fix winapi initialization on Python 2.5 on Windows

[akx]

This regression (apparently introduced in 1389278) was uncovered during testing #193/#230.

Rudimentary test result below. Doesn't seem to break 2.6/2.7 (though more eyes looking at get_thread_ident() might not hurt).

PYTHON: C:\Python25 -- LIBRARY: tip.paramiko -- TEST: agent_init.py
  Traceback: AttributeError: 'module' object has no attribute 'USHORT'
PYTHON: C:\Python26 -- LIBRARY: tip.paramiko -- TEST: agent_init.py
PYTHON: C:\Python27 -- LIBRARY: tip.paramiko -- TEST: agent_init.py
PYTHON: C:\Python25 -- LIBRARY: paramiko-git-akx -- TEST: agent_init.py
PYTHON: C:\Python26 -- LIBRARY: paramiko-git-akx -- TEST: agent_init.py
PYTHON: C:\Python27 -- LIBRARY: paramiko-git-akx -- TEST: agent_init.py

[lndbrg]

Same try except as on line 33?

[akx]

Thanks @lndbrg (and sorry for the history clobbering -- wanted the earlier mess out of sight).

[lndbrg]

Don't think this will work for all py versions.

py3 renamed thread to _thread.
The recommended interface for py3 is threading (py34 introduces threading.get_ident).
I think the compat matrix is:

interface:	py2.5	py2.6	py2.7	py3.2	py3.3	py3.4
thread	x	x	x	-	-	-
threading	x	x	x	x	x	x
_thread	-	-	-	x	x	x

interface:	py2.5	py2.6	py2.7	py3.2	py3.3	py3.4
thread.currentThread	x	x	x	-	-	-
thread.current_thread	-	x	x	-	-	-
threading.currentThread	x	x	x	-	-	-
threading.current_thread	-	x	x	x	x	x
threading.get_ident	-	-	-	-	-	x
thread.get_ident	x	x	x	-	-	-
_thread.get_ident	-	-	-	x	x	x

Looks like you need to import threading and check for currentThread or current_thread and then call get_ident on that.

[lndbrg]

Updated the above comment. Threading exists on all of the python platforms we try to support.

[akx]

Now that's thorough. Thank you again.

So, I suppose

def get_thread_ident():
  try:
     return thread.get_ident()
  except AttributeError:
     return threading.current_thread().ident

would do the trick?

[lndbrg]

With the updated matrix I think this would do the trick:

def get_thread_ident():
  current_thread =  None
  try:
     current_thread = threading.currentThread()
  except AttributeError:
      current_thread = threading.current_thread()
  return current_thread.get_ident()

[akx]

The original bug was that _MainThread on Python 2.5 does not have an ident member, so I don't think that that'd work.

[lndbrg]

That's because ident is new in 2.6 on the threading module. But get_ident exists on thread and _thread.

something like:

try:
   import _thread as thread
except ImportError:
   import thread

thread.get_ident()

Untested.

[bitprophet]

If this is becoming too much of a pain, feel free to punt on it - I mentioned 2.5 in #193 as a matter of course, but once the Python 3 support lands we will discontinue 2.5 support anyway. So this might be moot.

Dig if you want - it'd be nice for the last pre-Py3 releases to work well on 2.5 for Windows - but I'm OK to merge #193 without this functioning if it'll save time.

EDIT: note that I've only skimmed this so far, recent comments sound like you're still kicking things around? If that's not the case and this can be merge as-is, that's cool too.

[lndbrg]

Ignoring py2.5, this looks like the best solution: threading.current_thread().ident
@akx what do you say?

[akx]

Well, I flipped the order the identity sources are tried, so now Py2.5 compatibility is the uncommon case.

I think this (and #230) would leave the last pre-Py3 version compatible with Win+Py2.5. At least for the agent/winapi bit, anyway...

[bitprophet]

Thanks again. Spoke to @lndbrg on IRC a bit and committed a7ea048 to clean things up a bit further (re: his above comments.)

Merged into mainline (1.10 -> master), will close this and the other PR (had to cherry pick so it won't autoclose) and move discussion back into #193.