hubs: get_default_hub() on Windows broken by kqueue; Thanks to Paul Oppenheim

Fixes https://github.com/eventlet/eventlet/issues/38
+autopep8

eventlet/hubs/__init__.py

@@ -16,12 +16,13 @@ __all__ = ["use_hub", "get_hub", "get_default_hub", "trampoline"]
 threading = patcher.original('threading')
 _threadlocal = threading.local()
 
+
 def get_default_hub():
     """Select the default hub implementation based on what multiplexing
     libraries are installed.  The order that the hubs are tried is:
 
-    * twistedr
     * epoll
+    * kqueue
     * poll
     * select
 
@@ -91,12 +92,14 @@ def use_hub(mod=None):
                     mod, found = entry.load(), True
                     break
             if not found:
-                mod = __import__('eventlet.hubs.' + mod, globals(), locals(), ['Hub'])
+                mod = __import__(
+                    'eventlet.hubs.' + mod, globals(), locals(), ['Hub'])
     if hasattr(mod, 'Hub'):
         _threadlocal.Hub = mod.Hub
     else:
         _threadlocal.Hub = mod
 
+
 def get_hub():
     """Get the current event hub singleton object.
 
@@ -113,6 +116,8 @@ def get_hub():
     return hub
 
 from eventlet import timeout
+
+
 def trampoline(fd, read=None, write=None, timeout=None,
                timeout_exc=timeout.Timeout):
     """Suspend the current coroutine until the given socket object or file
@@ -133,7 +138,8 @@ def trampoline(fd, read=None, write=None, timeout=None,
     hub = get_hub()
     current = greenlet.getcurrent()
     assert hub.greenlet is not current, 'do not call blocking functions from the mainloop'
-    assert not (read and write), 'not allowed to trampoline for reading and writing'
+    assert not (
+        read and write), 'not allowed to trampoline for reading and writing'
     try:
         fileno = fd.fileno()
     except AttributeError:

eventlet/hubs/kqueue.py

@@ -8,9 +8,15 @@ sleep = time.sleep
 from eventlet.support import get_errno, clear_sys_exc_info
 from eventlet.hubs.hub import BaseHub, READ, WRITE, noop
 
+
+if getattr(select, 'kqueue', None) is None:
+    raise ImportError('No kqueue implementation found in select module')
+
+
 FILTERS = {READ: select.KQ_FILTER_READ,
            WRITE: select.KQ_FILTER_WRITE}
 
+
 class Hub(BaseHub):
     MAX_EVENTS = 100
 

tests/hub_test.py

@@ -2,6 +2,7 @@ from __future__ import with_statement
 import sys
 
 from tests import LimitedTestCase, main, skip_with_pyevent, skip_if_no_itimer, skip_unless
+from tests.patcher_test import ProcessBase
 import time
 import eventlet
 from eventlet import hubs
@@ -11,11 +12,15 @@ from eventlet.semaphore import Semaphore
 from eventlet.support import greenlets
 
 DELAY = 0.001
+
+
 def noop():
     pass
 
+
 class TestTimerCleanup(LimitedTestCase):
     TEST_TIMEOUT = 2
+
     @skip_with_pyevent
     def test_cancel_immediate(self):
         hub = hubs.get_hub()
@@ -30,7 +35,6 @@ class TestTimerCleanup(LimitedTestCase):
         self.assert_less_than_equal(hub.get_timers_count(), 1000 + stimers)
         self.assert_less_than_equal(hub.timers_canceled, 1000)
 
-
     @skip_with_pyevent
     def test_cancel_accumulated(self):
         hub = hubs.get_hub()
@@ -81,6 +85,7 @@ class TestTimerCleanup(LimitedTestCase):
 
 
 class TestScheduleCall(LimitedTestCase):
+
     def test_local(self):
         lst = [1]
         eventlet.spawn(hubs.get_hub().schedule_call_local, DELAY, lst.pop)
@@ -106,6 +111,7 @@ class TestScheduleCall(LimitedTestCase):
 
 
 class TestDebug(LimitedTestCase):
+
     def test_debug_listeners(self):
         hubs.get_hub().set_debug_listeners(True)
         hubs.get_hub().set_debug_listeners(False)
@@ -116,13 +122,17 @@ class TestDebug(LimitedTestCase):
 
 
 class TestExceptionInMainloop(LimitedTestCase):
+
     def test_sleep(self):
-        # even if there was an error in the mainloop, the hub should continue to work
+        # even if there was an error in the mainloop, the hub should continue
+        # to work
         start = time.time()
         eventlet.sleep(DELAY)
         delay = time.time() - start
 
-        assert delay >= DELAY*0.9, 'sleep returned after %s seconds (was scheduled for %s)' % (delay, DELAY)
+        assert delay >= DELAY * \
+            0.9, 'sleep returned after %s seconds (was scheduled for %s)' % (
+                delay, DELAY)
 
         def fail():
             1 // 0
@@ -133,10 +143,13 @@ class TestExceptionInMainloop(LimitedTestCase):
         eventlet.sleep(DELAY)
         delay = time.time() - start
 
-        assert delay >= DELAY*0.9, 'sleep returned after %s seconds (was scheduled for %s)' % (delay, DELAY)
+        assert delay >= DELAY * \
+            0.9, 'sleep returned after %s seconds (was scheduled for %s)' % (
+                delay, DELAY)
 
 
 class TestExceptionInGreenthread(LimitedTestCase):
+
     @skip_unless(greenlets.preserves_excinfo)
     def test_exceptionpreservation(self):
         # events for controlling execution order
@@ -193,6 +206,7 @@ class TestExceptionInGreenthread(LimitedTestCase):
 
 
 class TestHubSelection(LimitedTestCase):
+
     def test_explicit_hub(self):
         if getattr(hubs.get_hub(), 'uses_twisted_reactor', None):
             # doesn't work with twisted
@@ -207,6 +221,7 @@ class TestHubSelection(LimitedTestCase):
 
 class TestHubBlockingDetector(LimitedTestCase):
     TEST_TIMEOUT = 10
+
     @skip_with_pyevent
     def test_block_detect(self):
         def look_im_blocking():
@@ -234,6 +249,7 @@ class TestHubBlockingDetector(LimitedTestCase):
 
 class TestSuspend(LimitedTestCase):
     TEST_TIMEOUT = 3
+
     def test_suspend_doesnt_crash(self):
         import errno
         import os
@@ -269,6 +285,7 @@ except eventlet.Timeout:
 
 
 class TestBadFilenos(LimitedTestCase):
+
     @skip_with_pyevent
     def test_repeated_selects(self):
         from eventlet.green import select
@@ -276,8 +293,8 @@ class TestBadFilenos(LimitedTestCase):
         self.assertRaises(ValueError, select.select, [-1], [], [])
 
 
-from tests.patcher_test import ProcessBase
 class TestFork(ProcessBase):
+
     @skip_with_pyevent
     def test_fork(self):
         new_mod = """
@@ -370,6 +387,41 @@ class TestDeadRunLoop(LimitedTestCase):
 class Foo(object):
     pass
 
+
+class TestDefaultHub(ProcessBase):
+
+    def test_kqueue_unsupported(self):
+        # https://github.com/eventlet/eventlet/issues/38
+        # get_hub on windows broken by kqueue
+        module_source = r'''
+# Simulate absence of kqueue even on platforms that support it.
+import select
+try:
+    del select.kqueue
+except AttributeError:
+    pass
+
+import __builtin__
+original_import = __builtin__.__import__
+
+def fail_import(name, *args, **kwargs):
+    if 'epoll' in name:
+        raise ImportError('disabled for test')
+    if 'kqueue' in name:
+        print('kqueue tried')
+    return original_import(name, *args, **kwargs)
+
+__builtin__.__import__ = fail_import
+
+
+import eventlet.hubs
+eventlet.hubs.get_default_hub()
+print('ok')
+'''
+        self.write_to_tempfile('newmod', module_source)
+        output, _ = self.launch_subprocess('newmod.py')
+        self.assertEqual(output, 'kqueue tried\nok\n')
+
+
 if __name__ == '__main__':
     main()
-