Lock select lists to avoid invalid states (particularly on closing)

nemubot/server/__init__.py

@@ -16,6 +16,9 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import threading
+
+_lock = threading.Lock()
 
 # Lists for select
 _rlist = []

nemubot/server/abstract.py

@@ -20,7 +20,7 @@ import io
 import logging
 import queue
 
-from nemubot.server import _rlist, _wlist, _xlist
+from nemubot.server import _lock, _rlist, _wlist, _xlist
 
 # Extends from IOBase in order to be compatible with select function
 class AbstractServer(io.IOBase):
@@ -71,6 +71,7 @@ class AbstractServer(io.IOBase):
         """Generic close function that register the server un _{r,w,x}list in
         case of successful _close"""
         self.logger.info("Closing connection to %s", self.id)
+        _lock.acquire()
         if not hasattr(self, "_close") or self._close():
             if self in _rlist:
                 _rlist.remove(self)
@@ -78,7 +79,9 @@ class AbstractServer(io.IOBase):
                 _wlist.remove(self)
             if self in _xlist:
                 _xlist.remove(self)
+            _lock.release()
             return True
+        _lock.release()
         return False
 
 

nemubot/server/socket.py

@@ -73,14 +73,19 @@ class SocketServer(AbstractServer):
     def _close(self):
         import socket
 
+        from nemubot.server import _lock
+        _lock.release()
         self._sending_queue.join()
+        _lock.acquire()
         if self.connected:
             try:
                 self.socket.shutdown(socket.SHUT_RDWR)
                 self.socket.close()
             except socket.error:
                 pass
+
             self.socket = None
+
         return True