Don't implement poll when python doesn't have one

gevent/select.py

@@ -77,8 +77,8 @@ def select(rlist, wlist, xlist, timeout=None):
         for watcher in watchers:
             watcher.stop()
 
-
-class PollResult(object):
+if original_poll is not None:
+    class PollResult(object):
         __slots__ = ['events', 'event']
 
         def __init__(self):
@@ -93,14 +93,12 @@ class PollResult(object):
             self.event.set()
 
 
-class poll(object):
+    class poll(object):
         def __init__(self):
             self.fds = {}
             self.loop = get_hub().loop
             # Using the original poll to handle immediate response polling.
             # Using the ev based way, we receive a signal on the first descriptor.
-        self.poll_obj = None
-        if original_poll is not None:
             self.poll_obj = original_poll()
 
         def register(self, fd, eventmask=POLLIN | POLLOUT):
@@ -110,16 +108,13 @@ class poll(object):
             watcher = self.loop.io(get_fileno(fd), flags)
             watcher.priority = self.loop.MAXPRI
             self.fds[fd] = watcher
-        if self.poll_obj:
             self.poll_obj.register(fd, eventmask)
 
         def modify(self, fd, eventmask):
             self.register(fd, eventmask)
-        if self.poll_obj:
             self.poll_obj.modify(fd, eventmask)
 
         def poll(self, timeout=None):
-        if self.poll_obj:
             results = self.poll_obj.poll(0)
             if results:
                 return results
@@ -137,5 +132,4 @@ class poll(object):
 
         def unregister(self, fd):
             self.fds.pop(fd, None)
-        if self.poll_obj:
             self.poll_obj.unregister(fd)