Close CLOSE_WAIT sockets by default (#1104)

* Add close_half_closed_sockets function

* Call close_half_closed_sockets in xmlrpcapi by default

tools/rosmaster/src/rosmaster/util.py

@@ -49,6 +49,8 @@
 monkey_patch()
 del monkey_patch
 
+import socket
+
 _proxies = {} #cache ServerProxys
 def xmlrpcapi(uri):
     """
@@ -62,9 +64,19 @@ def xmlrpcapi(uri):
         return None
     if not uri in _proxies:
         _proxies[uri] = ServerProxy(uri)
+    close_half_closed_sockets()
     return _proxies[uri]
 
 
+def close_half_closed_sockets():
+    for proxy in _proxies.values():
+        transport = proxy("transport")
+        if transport._connection and transport._connection[1] is not None and transport._connection[1].sock is not None:
+            state = transport._connection[1].sock.getsockopt(socket.SOL_TCP, socket.TCP_INFO)
+            if state == 8:  # CLOSE_WAIT
+                transport.close()
+
+
 def remove_server_proxy(uri):
     if uri in _proxies:
         del _proxies[uri]