avoid race conditions in read_*/write_* methods

using one RLock per Module
+ init generalConfig for all tests

Change-Id: I88db6cacdb4aaac2ecd56644ccd6a3e5fd2d1cf2
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/28005
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

secop/modules.py

@@ -25,6 +25,7 @@
 
 import time
 from queue import Queue, Empty
+import threading
 from collections import OrderedDict
 from functools import wraps
 
@@ -136,6 +137,7 @@ class HasAccessibles(HasProperties):
 
                     @wraps(rfunc)  # handles __wrapped__ and __doc__
                     def new_rfunc(self, pname=pname, rfunc=rfunc):
+                        with self.accessLock:
                             try:
                                 value = rfunc(self)
                                 self.log.debug("read_%s returned %r", pname, value)
@@ -175,6 +177,7 @@ class HasAccessibles(HasProperties):
 
                         @wraps(wfunc)  # handles __wrapped__ and __doc__
                         def new_wfunc(self, value, pname=pname, wfunc=wfunc):
+                            with self.accessLock:
                                 pobj = self.accessibles[pname]
                                 self.log.debug('validate %r for %r', value, pname)
                                 # we do not need to handle errors here, we do not
@@ -293,6 +296,7 @@ class Module(HasAccessibles):
         self.startModuleDone = False
         self.remoteLogHandler = None
         self.changePollinterval = Queue()  # used for waiting between polls and transmit info to the thread
+        self.accessLock = threading.RLock()
         errors = []
 
         # handle module properties
@@ -468,6 +472,7 @@ class Module(HasAccessibles):
     def announceUpdate(self, pname, value=None, err=None, timestamp=None):
         """announce a changed value or readerror"""
 
+        with self.accessLock:
             # TODO: remove readerror 'property' and replace value with exception
             pobj = self.parameters[pname]
             timestamp = timestamp or time.time()
@@ -486,7 +491,7 @@ class Module(HasAccessibles):
             if err:
                 err = secop_error(err)
                 if str(err) == str(pobj.readerror):
-                return  # do call updates for repeated errors
+                    return  # no updates for repeated errors
             elif not changed and timestamp < (pobj.timestamp or 0) + self.omit_unchanged_within:
                 # no change within short time -> omit
                 return

secop/rwhandler.py

@@ -127,6 +127,7 @@ class ReadHandler(Handler):
 
     def wrap(self, key):
         def method(module, pname=key, func=self.func):
+            with module.accessLock:
                 value = func(module, pname)
                 if value is Done:
                     return getattr(module, pname)
@@ -148,6 +149,7 @@ class CommonReadHandler(ReadHandler):
 
     def wrap(self, key):
         def method(module, pname=key, func=self.func):
+            with module.accessLock:
                 ret = func(module)
                 if ret not in (None, Done):
                     raise ProgrammingError('a method wrapped with CommonReadHandler must not return any value')
@@ -165,6 +167,7 @@ class WriteHandler(Handler):
     def wrap(self, key):
         @wraps(self.func)
         def method(module, value, pname=key, func=self.func):
+            with module.accessLock:
                 value = func(module, pname, value)
                 if value is not Done:
                     setattr(module, pname, value)
@@ -201,6 +204,7 @@ class CommonWriteHandler(WriteHandler):
     def wrap(self, key):
         @wraps(self.func)
         def method(module, value, pname=key, func=self.func):
+            with module.accessLock:
                 values = WriteParameters(module)
                 values[pname] = value
                 ret = func(module, values)

test/conftest.py

@@ -1,6 +1,12 @@
 # content of conftest.py
 
 import pytest
+from secop.lib import generalConfig
+
+
+@pytest.fixture(scope="session", autouse=True)
+def general_config():
+    generalConfig.testinit()
 
 
 @pytest.fixture(scope="module")