avoid deadlock in proxy

in secop.proxy the callers modules method announceUpdate is
called from an other thread while the accessLock is locked,
creating a deadlock. solve this by creating an other lock
'updateLock' for the update.

+ add status parameter even to non-Readable proxy modules,
  in order to indicate a failed connection
+ fix an error in secop_psi/softcal.py

Change-Id: Iae7c6d5a74001150a47aa9dc99209c15d972cd5e
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/28130
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

secop/modules.py

@@ -318,7 +318,8 @@ class Module(HasAccessibles):
         self.initModuleDone = False
         self.startModuleDone = False
         self.remoteLogHandler = None
-        self.accessLock = threading.RLock()
+        self.accessLock = threading.RLock()  # for read_* / write_* methods
+        self.updateLock = threading.RLock()  # for announceUpdate
         self.polledModules = []  # modules polled by thread started in self.startModules
         errors = []
 
@@ -495,7 +496,7 @@ class Module(HasAccessibles):
     def announceUpdate(self, pname, value=None, err=None, timestamp=None):
         """announce a changed value or readerror"""
 
-        with self.accessLock:
+        with self.updateLock:
             # TODO: remove readerror 'property' and replace value with exception
             pobj = self.parameters[pname]
             timestamp = timestamp or time.time()