Fix "maximum recursion depth exceeded in GreenSocket.__del__"

Closes eventlet#137
Closes eventlet#148

eventlet/greenio.py

@@ -119,6 +119,9 @@ class GreenSocket(object):
     to save syscalls.
     """
 
+    # This placeholder is to prevent __getattr__ from creating an infinite call loop
+    fd = None
+
     def __init__(self, family_or_realsock=socket.AF_INET, *args, **kwargs):
         should_set_nonblocking = kwargs.pop('set_nonblocking', True)
         if isinstance(family_or_realsock, six.integer_types):
@@ -175,6 +178,8 @@ def _set_io_refs(self, value):
     # If we find such attributes - only attributes having __get__ might be cached.
     # For now - I do not want to complicate it.
     def __getattr__(self, name):
+        if self.fd is None:
+            raise AttributeError(name)
         attr = getattr(self.fd, name)
         setattr(self, name, attr)
         return attr
@@ -216,7 +221,10 @@ def _mark_as_closed(self):
         self._closed = True
 
     def __del__(self):
-        self.close()
+        # This is in case self.close is not assigned yet (currently the constructor does it)
+        close = getattr(self, 'close', None)
+        if close is not None:
+            close()
 
     def connect(self, address):
         if self.act_non_blocking:

tests/greenio_test.py

@@ -9,10 +9,12 @@
 import sys
 import tempfile
 
+from nose.tools import eq_
+
 from eventlet import event, greenio, debug
 from eventlet.hubs import get_hub
 from eventlet.green import select, socket, time, ssl
-from eventlet.support import get_errno, six
+from eventlet.support import capture_stderr, get_errno, six
 from tests import (
     LimitedTestCase, main,
     skip_with_pyevent, skipped, skip_if, skip_on_windows,
@@ -895,5 +897,21 @@ def test_set_nonblocking():
     assert new_flags == (orig_flags | os.O_NONBLOCK)
 
 
+def test_socket_del_fails_gracefully_when_not_fully_initialized():
+    # Regression introduced in da87716714689894f23d0db7b003f26d97031e83, reported in:
+    # * GH #137 https://github.com/eventlet/eventlet/issues/137
+    # * https://bugs.launchpad.net/oslo.messaging/+bug/1369999
+
+    class SocketSubclass(socket.socket):
+
+        def __init__(self):
+            pass
+
+    with capture_stderr() as err:
+        SocketSubclass()
+
+    assert err.getvalue() == ''
+
+
 if __name__ == '__main__':
     main()