backport fix for #805.

changelog.rst

@@ -13,6 +13,8 @@
 - :class:`selectors.SelectSelector` is properly monkey-patched
   regardless of the order of imports. Reported in :issue:`835` by
   Przemysław Węgrzyn.
+- Python 2: ``reload(site)`` no longer fails with a ``TypeError`` if
+  gevent has been imported. Reported in :issue:`805` by Jake Hilton.
 
 1.1.1 (Apr 4, 2016)
 ===================

gevent/__init__.py

@@ -82,9 +82,10 @@ class _signal_metaclass(type):
         return getattr(_signal_module, name)
 
     def __setattr__(self, name, value):
-        # Because we can't know whether to try to go to the module
-        # or the class, we don't allow setting an attribute after the fact
-        raise TypeError("Cannot set attribute")
+        # For symmetry with getattr and dir, pass all
+        # attribute setting on to the module. (This makes
+        # reloading work, see issue #805)
+        setattr(_signal_module, name, value)
 
     def __instancecheck__(self, instance):
         return isinstance(instance, _signal_class)

gevent/monkey.py

@@ -476,10 +476,10 @@ def patch_select(aggressive=True):
         assert select.select is not orig_select_select
         selectors = __import__('selectors')
         if selectors.SelectSelector._select in (select.select, orig_select_select):
-             def _select(self, *args, **kwargs): # pylint:disable=unused-argument
-                 return select.select(*args, **kwargs)
-             selectors.SelectSelector._select = _select
-             _select._gevent_monkey = True
+            def _select(self, *args, **kwargs): # pylint:disable=unused-argument
+                return select.select(*args, **kwargs)
+            selectors.SelectSelector._select = _select
+            _select._gevent_monkey = True
 
         if aggressive:
             # If `selectors` had already been imported before we removed

greentest/greentest.py

@@ -71,12 +71,19 @@ PLATFORM_SPECIFIC_SUFFIXES = ['2', '279', '3']
 if sys.platform.startswith('win'):
     PLATFORM_SPECIFIC_SUFFIXES.append('posix')
 
+PY2 = None
+PY3 = None
+PY34 = None
+
 NON_APPLICABLE_SUFFIXES = []
 if sys.version_info[0] == 3:
     # Python 3
     NON_APPLICABLE_SUFFIXES.extend(('2', '279'))
     PY2 = False
     PY3 = True
+    if sys.version_info[1] >= 4:
+        PY34 = True
+
 if sys.version_info[0] == 2:
     # Any python 2
     PY3 = False
@@ -157,6 +164,11 @@ def wrap_timeout(timeout, method):
     return wrapped
 
 
+def ignores_leakcheck(func):
+    func.ignore_leakcheck = True
+    return func
+
+
 def wrap_refcount(method):
     if not RUN_LEAKCHECKS:
         return method

greentest/test__signal.py

@@ -41,6 +41,30 @@ if hasattr(signal, 'SIGALRM'):
             finally:
                 sig.cancel()
 
+        @greentest.ignores_leakcheck
+        def test_reload(self):
+            # The site module tries to set attributes
+            # on all the modules that are loaded (specifically, __file__).
+            # If gevent.signal is loaded, and is our compatibility shim,
+            # this used to fail on Python 2: sys.modules['gevent.signal'] has no
+            # __loader__ attribute, so site.py's main() function tries to do
+            # gevent.signal.__file__ = os.path.abspath(gevent.signal.__file__), which
+            # used to not be allowed. (Under Python 3, __loader__ is present so this
+            # doesn't happen). See
+            # https://github.com/gevent/gevent/issues/805
+
+            import gevent.signal # make sure it's in sys.modules pylint:disable=redefined-outer-name
+            assert gevent.signal
+            import site
+            if greentest.PY34:
+                from importlib import reload as reload_module
+            elif greentest.PY3:
+                from imp import reload as reload_module
+            else:
+                # builtin on py2
+                reload_module = reload # pylint:disable=undefined-variable
+
+            reload_module(site)
 
 if __name__ == '__main__':
     greentest.main()