make secop.poller.Poller default

modules using the old poller (now called secop.poller.BasicPoller)
need to explcitly declare it (pollerClass = BasicPoller)

BasicPoller is still used in:

secop_mlz/amagnet.py
secop_mlz/entangle.py
secop/simulation.py

Remark: before removing BasicPoller we may need a replacement for
Readable.pollParams

Change-Id: If1ae8b68e02f13e601334656b818337c882e06cc
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/21910
Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

secop/modules.py

@@ -30,11 +30,12 @@ from secop.datatypes import EnumType, FloatRange, BoolType, IntRange, \
     StringType, TupleOf, get_datatype, ArrayOf, TextType
 from secop.errors import ConfigError, ProgrammingError
 from secop.lib import formatException, \
-    formatExtendedStack, mkthread, unset_value
+    formatExtendedStack, mkthread
 from secop.lib.enum import Enum
 from secop.metaclass import ModuleMeta
 from secop.params import PREDEFINED_ACCESSIBLES, Command, Override, Parameter, Parameters, Commands
 from secop.properties import HasProperties, Property
+from secop.poller import Poller, BasicPoller
 
 
 # XXX: connect with 'protocol'-Modules.
@@ -86,6 +87,8 @@ class Module(HasProperties, metaclass=ModuleMeta):
     # reference to the dispatcher (used for sending async updates)
     DISPATCHER = None
 
+    pollerClass = Poller
+
     def __init__(self, name, logger, cfgdict, srv):
         # remember the dispatcher object (for the async callbacks)
         self.DISPATCHER = srv.dispatcher
@@ -179,13 +182,14 @@ class Module(HasProperties, metaclass=ModuleMeta):
         #    is not specified in cfgdict
         for k, v in self.parameters.items():
             if k not in cfgdict:
-                if v.default is unset_value and k != 'value':
+                if v.default is None:
-                    # unset_value is the one single value you can not specify....
+                    if not v.poll:
-                    raise ConfigError('Module %s: Parameter %r has no default '
+                        raise ConfigError('Module %s: Parameter %r has no default '
-                                      'value and was not given in config!' %
+                                          'value and was not given in config!' %
-                                      (self.name, k))
+                                          (self.name, k))
-                # assume default value was given
+                    cfgdict[k] = v.datatype.default
-                cfgdict[k] = v.default
+                else:
+                    cfgdict[k] = v.default
 
         # 5) 'apply' config:
         #    pass values through the datatypes and store as attributes
@@ -265,7 +269,7 @@ class Readable(Module):
     parameters = {
         'value':        Parameter('current value of the Module', readonly=True,
                                   default=0., datatype=FloatRange(),
-                                  unit='', poll=True,
+                                  poll=True,
                                  ),
         'pollinterval': Parameter('sleeptime between polls', default=5,
                                   readonly=False,
@@ -279,12 +283,12 @@ class Readable(Module):
     }
 
     def startModule(self, started_callback):
-        '''start polling thread'''
+        '''start basic polling thread'''
-        if hasattr(self, 'pollerClass'): # an other poller is used
+        if issubclass(self.pollerClass, BasicPoller):
-            started_callback()
+            # use basic poller for legacy code
-        else:
-            # basic poller kept for reference
             mkthread(self.__pollThread, started_callback)
+        else:
+            started_callback()
 
     def __pollThread(self, started_callback):
         while True:

secop/poller.py

@@ -58,17 +58,13 @@ class PollerBase:
         poller as value.
         <name> is module.iodev or module.name, if iodev is not present
         '''
-        try:
-            pollerClass = module.pollerClass
-        except AttributeError:
-            return # no pollerClass -> fall back to simple poller
         # for modules with the same iodev, a common poller is used,
         # modules without iodev all get their own poller
         name = getattr(module, 'iodev', module.name)
-        poller = table.get((pollerClass, name), None)
+        poller = table.get((cls, name), None)
         if poller is None:
-            poller = pollerClass(name)
+            poller = cls(name)
-            table[(pollerClass, name)] = poller
+            table[(cls, name)] = poller
         poller.add_to_poller(module)
 
     def start(self, started_callback):
@@ -97,8 +93,6 @@ class PollerBase:
     def __repr__(self):
         return '%s(%r)' % (self.__class__.__name__, self.name)
 
-    __nonzero__ = __bool__  # Py2/3 compat
-
 
 class Poller(PollerBase):
     '''a standard poller
@@ -246,4 +240,14 @@ class Poller(PollerBase):
         '''is there any poll item?'''
         return any(self.queues.values())
 
-    __nonzero__ = __bool__  # Py2/3 compat
+
+class BasicPoller(PollerBase):
+    """basic poller
+
+    this is just a dummy, the poller thread is started in Readable.startModule
+    """
+    # pylint: disable=abstract-method
+
+    @classmethod
+    def add_to_table(cls, table, module):
+        pass

secop/protocol/interface/tcp.py

@@ -122,8 +122,9 @@ class TCPRequestHandler(socketserver.BaseRequestHandler):
                 try:
                     msg = decode_msg(origin)
                 except Exception as err:
-                    # we have to decode 'origin' here. utf-8 and ascii may lead to encoding errors
+                    # we have to decode 'origin' here
-                    msg = origin.decode('latin-1').split(' ', 3)
+                    # use latin-1, as utf-8 or ascii may lead to encoding errors
+                    msg = origin.decode('latin-1').split(' ', 3) + (None,) # make sure len(msg) > 1
                     result = (ERRORPREFIX + msg[0], msg[1], ['InternalError', str(err),
                                                              {'exception': formatException(),
                                                               'traceback': formatExtendedStack()}])

secop/server.py

@@ -185,10 +185,7 @@ class Server:
         for modname, modobj in self.modules.items():
             self.log.info('registering module %r' % modname)
             self.dispatcher.register_module(modobj, modname, modobj.properties['export'])
-            try:
+            modobj.pollerClass.add_to_table(pollTable, modobj)
-                modobj.pollerClass.add_to_table(pollTable, modobj)
-            except AttributeError:
-                pass
             # also call earlyInit on the modules
             modobj.earlyInit()
 

secop/simulation.py

@@ -27,10 +27,12 @@ from time import sleep
 
 from secop.datatypes import FloatRange
 from secop.lib import mkthread
-from secop.modules import Drivable, Module, Parameter, Readable, Writable
+from secop.modules import Drivable, Module, Parameter, Readable, Writable, BasicPoller
 
 
 class SimBase:
+    pollerClass = BasicPoller
+
     def __init__(self, cfgdict):
         # spice up parameters if requested by extra property
         # hint: us a comma-separated list if mor than one extra_param
@@ -68,7 +70,7 @@ class SimBase:
         self.log.info('sim thread ended')
 
     def sim(self):
-        return True
+        return True # nothing to do, stop thread
 
     def read_value(self):
         if 'jitter' in self.accessibles:
@@ -138,6 +140,7 @@ class SimDrivable(SimBase, Drivable):
             except Exception:
                 pass
         self.status = self.Status.IDLE, ''
+        return False # keep thread running
 
     def _hw_wait(self):
         while self.status[0] == self.Status.BUSY:

secop_mlz/amagnet.py

@@ -31,7 +31,7 @@ import math
 from secop.datatypes import ArrayOf, FloatRange, StringType, StructOf, TupleOf
 from secop.errors import ConfigError, DisabledError
 from secop.lib.sequence import SequencerMixin, Step
-from secop.modules import Drivable, Parameter
+from secop.modules import Drivable, Parameter, BasicPoller
 
 
 class GarfieldMagnet(SequencerMixin, Drivable):
@@ -47,6 +47,8 @@ class GarfieldMagnet(SequencerMixin, Drivable):
     the symmetry setting selects which.
     """
 
+    pollerClass = BasicPoller
+
     parameters = {
         'subdev_currentsource': Parameter('(bipolar) Powersupply', datatype=StringType(), readonly=True, export=False),
         'subdev_enable': Parameter('Switch to set for on/off', datatype=StringType(), readonly=True, export=False),

secop_mlz/entangle.py

@@ -41,7 +41,7 @@ from secop.errors import CommunicationFailedError, \
     ConfigError, HardwareError, ProgrammingError
 from secop.lib import lazy_property
 from secop.modules import Command, Drivable, \
-    Module, Override, Parameter, Readable
+    Module, Override, Parameter, Readable, BasicPoller
 
 #####
 
@@ -158,6 +158,8 @@ class PyTangoDevice(Module):
     execution and attribute operations with logging and exception mapping.
     """
 
+    pollerClass = BasicPoller
+
     parameters = {
         'comtries': Parameter('Maximum retries for communication',
                           datatype=IntRange(1, 100), default=3, readonly=False,