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/simulation.py

@@ -27,13 +27,10 @@ from time import sleep
 
 from secop.datatypes import FloatRange
 from secop.lib import mkthread
-from secop.modules import BasicPoller, Drivable, \
-    Module, Parameter, Readable, Writable, Command
+from secop.modules import Drivable, Module, Parameter, Readable, Writable, Command
 
 
 class SimBase:
-    pollerClass = BasicPoller
-
     def __new__(cls, devname, logger, cfgdict, dispatcher):
         extra_params = cfgdict.pop('extra_params', '') or cfgdict.pop('.extra_params', '')
         attrs = {}
@@ -120,7 +117,7 @@ class SimDrivable(SimReadable, Drivable):
             self._value = self.target
         speed *= self.interval
         try:
-            self.pollParams(0)
+            self.doPoll()
         except Exception:
             pass
 
@@ -133,7 +130,7 @@ class SimDrivable(SimReadable, Drivable):
                 self._value = self.target
             sleep(self.interval)
             try:
-                self.pollParams(0)
+                self.doPoll()
             except Exception:
                 pass
         self.status = self.Status.IDLE, ''