From 32d38b11e1a6c43fd0a082faf3d58d6a1661e769 Mon Sep 17 00:00:00 2001
From: Jan David Mol <mol@astron.nl>
Date: Wed, 2 Dec 2020 10:07:09 +0100
Subject: [PATCH] Move reconnect functionality to separate class
---
RCUSCC/RCUSCC/RCUSCC.py | 91 +++++++++++++++++++++++------------------
1 file changed, 52 insertions(+), 39 deletions(-)
diff --git a/RCUSCC/RCUSCC/RCUSCC.py b/RCUSCC/RCUSCC/RCUSCC.py
index 62824eb73..68a2184ac 100644
--- a/RCUSCC/RCUSCC/RCUSCC.py
+++ b/RCUSCC/RCUSCC/RCUSCC.py
@@ -46,7 +46,7 @@ def fault_on_opcua_error(func):
except Exception as e:
self.error_stream("Communication with the OPC-UA server %s:%d failed. Reconnecting. Trace: %s" % (self.OPC_Server_Name, self.OPC_Server_Port, traceback.format_exc()))
self.set_state(DevState.FAULT)
- self._reconnect_opcua()
+ self.opcua_connector.reconnect()
return None
@@ -57,7 +57,7 @@ __all__ = ["RCUSCC", "main"]
class BackgroundConnector(Thread):
"""
- Run a function in the background, until it succeeds.
+ Run a connector function in the background, until it succeeds.
"""
def __init__(self, connect_func, try_interval=2, debug_stream=print):
@@ -84,6 +84,53 @@ class BackgroundConnector(Thread):
if not self.connected:
time.sleep(self.try_interval)
+class BackgroundReconnector(object):
+ """
+ Keeps a connection attempt going.
+ """
+
+ def __init__(self, connect_func, disconnect_func, debug_stream=print):
+ self.connect_func = connect_func
+ self.disconnect_func = disconnect_func
+ self.debug_stream = debug_stream
+
+ self._connect()
+
+ def _connect(self):
+ self.connector = BackgroundConnector(self.connect_func, debug_stream=self.debug_stream)
+ self.connector.start()
+
+ def reconnect(self):
+ """
+ Connect or reconnect to the OPC-UA server.
+ """
+
+ if self.connector.connecting:
+ # don't try twice in parallel
+ return
+
+ # reap previous instance
+ self.debug_stream("reaping previous connector")
+ self.connector.join()
+
+ # disconnect if necessary
+ self.debug_stream("disconnecting (if connected)")
+ self.disconnect_func()
+
+ # connect in the background
+ self.debug_stream("connecting")
+ self._connect()
+
+ def wait_connected(self):
+ """
+ Wait until a connection is established.
+ """
+
+ # wait for attempt to finish
+ self.connector.join()
+
+ if not self.connector.connected:
+ raise Exception("Could not connect to server")
class RCUSCC(Device):
"""
@@ -205,39 +252,6 @@ class RCUSCC(Device):
return DummyNode()
- def _reconnect_opcua(self):
- """
- Connect or reconnect to the OPC-UA server.
- """
-
- if self.opcua_connector:
- if self.opcua_connector.connecting:
- # don't try twice in parallel
- return
-
- # reap previous instance
- self.debug_stream("reaping previous connector")
- self.opcua_connector.join()
-
- self.debug_stream("disconnecting (if connected)")
- self._disconnect()
- self.debug_stream("connecting")
- self.opcua_connector = BackgroundConnector(self._init_opcua)
- self.opcua_connector.start()
-
- def _wait_opcua_connect(self):
- """
- Wait until an OPC-UA connection is established.
- """
-
- if not self.opcua_connector:
- # start connecting if not already
- self._reconnect_opcua()
-
- self.opcua_connector.join()
-
- if not self.opcua_connector.connected:
- raise Exception("Could not connect to OPC-UA server")
def _init_opcua(self):
self.debug_stream("Connecting to OPC-UA server %s:%d...", self.OPC_Server_Name, self.OPC_Server_Port)
@@ -305,9 +319,6 @@ class RCUSCC(Device):
# PROTECTED REGION ID(RCUSCC.init_device) ENABLED START #
self.set_state(DevState.INIT)
- # Thread to connect to OPC-UA in the background
- self.opcua_connector = None
-
# Init the dict that contains attribute to OPC-UA MP/CP mappings.
self.attribute_mapping = {}
@@ -350,7 +361,9 @@ class RCUSCC(Device):
# Set defaults to property values.
try:
- self._wait_opcua_connect()
+ # Connect to OPC-UA
+ self.opcua_connector = BackgroundReconnector(self._init_opcua, self._disconnect, self.debug_stream)
+ self.opcua_connector.wait_connected()
self.set_state(DevState.ON)
except Exception as e:
--
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