fix initwrite behaviour

with handlers, a parameter from the cfg file which is not the
first of parameters with the same handler were not written.
fix: write_<param> method is called for all parameters in
<module>.writeDict even if there is no poll entry.

with this fix, the write_<method> is called even when a parameter
is not polled.

secop/modules.py

@@ -346,16 +346,6 @@ class Module(HasProperties, metaclass=ModuleMeta):
     def initModule(self):
         self.log.debug('empty %s.initModule()' % self.__class__.__name__)
 
-    def startModule(self, started_callback):
-        """runs after init of all modules
-
-        started_callback to be called when thread spawned by late_init
-        or, if not implemented, immediately
-        might return a timeout value, if different from default
-        """
-        self.log.debug('empty %s.startModule()' % self.__class__.__name__)
-        started_callback()
-
     def pollOneParam(self, pname):
         """poll parameter <pname> with proper error handling"""
         try:
@@ -367,23 +357,34 @@ class Module(HasProperties, metaclass=ModuleMeta):
         except Exception:
             self.log.error(formatException())
 
-    def writeOrPoll(self, pname):
-        """write configured value for a parameter, if any, else poll
+    def writeInitParams(self, started_callback=None):
+        """write values for parameters with configured values
 
+        this must be called at the beginning of the poller thread
         with proper error handling
         """
-        try:
-            if pname in self.writeDict:
-                self.log.debug('write parameter %s', pname)
-                getattr(self, 'write_' + pname)(self.writeDict.pop(pname))
-            else:
-                getattr(self, 'read_' + pname)()
-        except SilentError:
-            pass
-        except SECoPError as e:
-            self.log.error(str(e))
-        except Exception:
-            self.log.error(formatException())
+        for pname in list(self.writeDict):
+            if pname in self.writeDict:  # this might not be true with handlers
+                try:
+                    self.log.debug('initialize parameter %s', pname)
+                    getattr(self, 'write_' + pname)(self.writeDict.pop(pname))
+                except SilentError:
+                    pass
+                except SECoPError as e:
+                    self.log.error(str(e))
+                except Exception:
+                    self.log.error(formatException())
+        if started_callback:
+            started_callback()
+
+    def startModule(self, started_callback):
+        """runs after init of all modules
+
+        started_callback to be called when the thread spawned by startModule
+        has finished its initial work
+        might return a timeout value, if different from default
+        """
+        mkthread(self.writeInitParams, started_callback)
 
 
 class Readable(Module):
@@ -424,7 +425,7 @@ class Readable(Module):
             # use basic poller for legacy code
             mkthread(self.__pollThread, started_callback)
         else:
-            started_callback()
+            super().startModule(self, started_callback)
 
     def __pollThread(self, started_callback):
         while True:
@@ -439,8 +440,7 @@ class Readable(Module):
 
     def __pollThread_inner(self, started_callback):
         """super simple and super stupid per-module polling thread"""
-        for pname in list(self.writeDict):
-            self.writeOrPoll(pname)
+        self.writeInitParams()
         i = 0
         fastpoll = self.pollParams(i)
         started_callback()

secop/params.py

@@ -115,7 +115,8 @@ class Parameter(Accessible):
                                  settable=False, default=False),
         'handler':     Property('[internal] overload the standard read and write functions',
                                  ValueType(), export=False, default=None, mandatory=False, settable=False),
-        'initwrite':   Property('[internal] write this parameter on initialization (default None: write if given in config)',
+        'initwrite':   Property('[internal] write this parameter on initialization'
+                                ' (default None: write if given in config)',
                                  NoneOr(BoolType()), export=False, default=None, mandatory=False, settable=False),
     }
 
@@ -139,11 +140,8 @@ class Parameter(Accessible):
             datatype.setProperty('unit', unit)
         super(Parameter, self).__init__(**kwds)
 
-        if self.initwrite:
-            if self.readonly:
-                raise ProgrammingError('can not have both readonly and initwrite!')
-            if not self.poll:
-                raise ProgrammingError('only polled parameters can have initwrite!')
+        if self.initwrite and self.readonly:
+            raise ProgrammingError('can not have both readonly and initwrite!')
 
         if self.constant is not None:
             self.properties['readonly'] = True

secop/poller.py

@@ -118,8 +118,10 @@ class Poller(PollerBase):
         self._stopped = False
         self.maxwait = 3600
         self.name = name
+        self.modules = []  # used for writeInitParams only
 
     def add_to_poller(self, module):
+        self.modules.append(module)
         factors = self.DEFAULT_FACTORS.copy()
         try:
             factors[DYNAMIC] = module.fast_pollfactor
@@ -227,11 +229,13 @@ class Poller(PollerBase):
             # nothing to do (else we might call time.sleep(float('inf')) below
             started_callback()
             return
+        for module in self.modules:
+            module.writeInitParams()
         # do all polls once and, at the same time, insert due info
         for _, queue in sorted(self.queues.items()):  # do SLOW polls first
             for idx, (_, _, (_, module, pobj, pname, factor)) in enumerate(queue):
                 lastdue = time.time()
-                module.writeOrPoll(pname)
+                module.pollOneParam(pname)
                 due = lastdue + min(self.maxwait, module.pollinterval * factor)
                 # in python 3 comparing tuples need some care, as not all objects
                 # are comparable. Inserting a unique idx solves the problem.

test/test_poller.py

@@ -163,7 +163,8 @@ class Module:
     def pollOneParam(self, pname):
         getattr(self, 'read_' + pname)()
 
-    writeOrPoll = pollOneParam
+    def writeInitParams(self):
+        pass
 
     def __repr__(self):
         rdict = self.__dict__.copy()