Improve server shutdown (#126)

* Cleaned up server shutdown process

* Fix exception on shutdown in Windows

client.py

@@ -3,7 +3,7 @@ import logging
 import threading
 from collections import deque
 
-from server import start_server
+from server import ZordonServer
 
 logger = logging.getLogger()
 
@@ -13,6 +13,7 @@ def __setup_buffer_handler():
 
     class BufferingHandler(logging.Handler, QObject):
         new_record = pyqtSignal(str)
+        flushOnClose = True
 
         def __init__(self, capacity=100):
             logging.Handler.__init__(self)
@@ -52,12 +53,25 @@ def __show_gui(buffer_handler):
     window.buffer_handler = buffer_handler
     window.show()
 
-    return app.exec()
+    exit_code = app.exec()
+
+    # cleanup: remove and close the GUI logging handler before interpreter shutdown
+    root_logger = logging.getLogger()
+    if buffer_handler in root_logger.handlers:
+        root_logger.removeHandler(buffer_handler)
+    try:
+        buffer_handler.close()
+    except Exception:
+        # never let logging cleanup throw during shutdown
+        pass
+
+    return exit_code
 
 if __name__ == '__main__':
     import sys
 
-    local_server_thread = threading.Thread(target=start_server, args=[True], daemon=True)
-    local_server_thread.start()
+    server = ZordonServer()
+    server.start_server()
     __show_gui(__setup_buffer_handler())
+    server.stop_server()
     sys.exit()