new poll mechanism

- remove secop.poller and basic poller
- regular polls for 'important' parameters done by method doPoll
- all other parameters are polled slower (slowInterval) and
  with lower priority (only one at a time when main poll is due)
- nopoll decorator for read_* to disable poll
- enablePoll attribute (default True) for disabling polling a module
- fast polls may be implemented by means of a statemachine
- configurable slow poll interval
+ allow a Parameter to override a Property (parameter
  Readable.pollinterval overrides Module.pollinterval)

Change-Id: Ib1b3453041a233678b7c4b4add22ac399670e447
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/27832
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>

secop/io.py

@@ -35,7 +35,6 @@ from secop.errors import CommunicationFailedError, CommunicationSilentError, \
     ConfigError, ProgrammingError
 from secop.modules import Attached, Command, \
     Communicator, Done, Module, Parameter, Property
-from secop.poller import REGULAR
 from secop.lib import generalConfig
 
 
@@ -109,7 +108,7 @@ class IOBase(Communicator):
     uri = Property('hostname:portnumber', datatype=StringType())
     timeout = Parameter('timeout', datatype=FloatRange(0), default=2)
     wait_before = Parameter('wait time before sending', datatype=FloatRange(), default=0)
-    is_connected = Parameter('connection state', datatype=BoolType(), readonly=False, default=False, poll=REGULAR)
+    is_connected = Parameter('connection state', datatype=BoolType(), readonly=False, default=False)
     pollinterval = Parameter('reconnect interval', datatype=FloatRange(0), readonly=False, default=10)
 
     _reconnectCallbacks = None
@@ -133,6 +132,9 @@ class IOBase(Communicator):
         self._conn = None
         self.is_connected = False
 
+    def doPoll(self):
+        self.read_is_connected()
+
     def read_is_connected(self):
         """try to reconnect, when not connected