issue #408: use compatible method to get thread ID.

mitogen/core.py

@@ -57,6 +57,11 @@ import imp
 # Absolute imports for <2.5.
 select = __import__('select')
 
+try:
+    import thread
+except ImportError:
+    import threading as thread
+
 try:
     import cPickle as pickle
 except ImportError:
@@ -1917,7 +1922,7 @@ class Latch(object):
         This disambiguates legitimate wake-ups, accidental writes to the FD,
         and buggy internal FD sharing.
         """
-        ident = threading.currentThread().ident
+        ident = thread.get_ident()
         return b(u'%010d-%016x-%016x' % (os.getpid(), int(id(self)), ident))
 
     COOKIE_SIZE = len(_make_cookie(None))