- Partial attempt at fixing PythonPolicies broken return values

git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@525 3ecf2c5c-341e-0410-92b4-d18e462d057c

src/backend/pyloader/ScriptAdapter.py

@@ -1,13 +1,6 @@
 import mutex, thread
 import sgpem
 
-## Var Global syncronization object
-_g_mutex = mutex.mutex()
-
-## @var Synchronized return value you can read from C++
-# when a threaded function returns
-_ret_val = None
-
 ## @brief This is an adapter class which acts as a proxy
 # for user-implemented policies
 #
@@ -28,7 +21,13 @@ class ScriptAdapter :
 
     ## @var The event to pass to Policy.sort_queue() after the asynchronous call
     _event = None
+    
+    ## @var Synchronized return value you can read from C++
+    # when a threaded function returns
+    _ret_val = None
 
+    ## Var Testable syncronization object
+    _g_mutex = mutex.mutex()
 
     ## @brief Constructor of ScriptAdapter
     #
@@ -43,7 +42,7 @@ class ScriptAdapter :
     #
     # @param self The caller object
     def async_configure(self):
-        _g_mutex.lock(ScriptAdapter._wrap_configure, self )
+        self._g_mutex.lock(ScriptAdapter._wrap_configure, self )
         
     def _wrap_configure(self):
         thread.start_new_thread(ScriptAdapter._wrap_configure_callback, (self,))
@@ -51,7 +50,7 @@ class ScriptAdapter :
     def _wrap_configure_callback(self):
         # call configure method
         self._policy.configure()
-        _g_mutex.unlock()
+        self._g_mutex.unlock()
 
 
     ## @brief Asynchronously call Policy.sort_queue()
@@ -63,7 +62,7 @@ class ScriptAdapter :
     # @param event The event to pass to sort_queue
     def async_sort_queue(self, event):
         self._event = event
-        _g_mutex.lock(ScriptAdapter._wrap_sort_queue, self)
+        self._g_mutex.lock(ScriptAdapter._wrap_sort_queue, self)
 
     def _wrap_sort_queue(self):
         thread.start_new_thread(ScriptAdapter._wrap_sort_queue_callback,
@@ -73,7 +72,7 @@ class ScriptAdapter :
         # here we retrieve and pass the ready queue
         queue = sgpem.Scheduler.get_instance().get_ready_queue()
         self._policy.sort_queue(event, queue)
-        _g_mutex.unlock()
+        self._g_mutex.unlock()
 
 
     ## @brief Asynchronously call Policy.is_preemptive()
@@ -86,19 +85,25 @@ class ScriptAdapter :
         thread.start_new_thread(ScriptAdapter._wrap_is_preemptive_callback, (self,))
 
     def _wrap_is_preemptive_callback(self):
-        _ret_val = self._policy.is_preemptive()
-        _g_mutex.unlock()
-
+        self._ret_val = self._policy.is_preemptive()
+        self._g_mutex.unlock()
     
     ## @brief Asynchronously call Policy.get_time_slice()
     #
     # @param self The caller object
     def async_get_time_slice(self):
-        _g_mutex.lock(ScriptAdapter._wrap_get_time_slice, self)
+        self._g_mutex.lock(ScriptAdapter._wrap_get_time_slice, self)
 
     def _wrap_get_time_slice(self):
         thread.start_new_thread(ScriptAdapter._wrap_get_time_slice_callback, (self,))
 
     def _wrap_get_time_slice_callback(self):
-        _ret_val = self._policy.get_time_slice()
-        _g_mutex.unlock()
+        self._ret_val = self._policy.get_time_slice()
+        self._g_mutex.unlock()
+
+    ## @brief Return the global shared variable with the methods' last return value
+    def get_return_value(self):
+        return self._ret_val
+
+    def test_lock(self):
+        return self._g_mutex.test()

src/backend/pyloader/python_policy.cc

@@ -31,8 +31,7 @@ using namespace std;
 // *strong* exception checking / handling!
 
 PythonPolicy::PythonPolicy(const char* name)
-  : _adapter(NULL), _adapter_dict(NULL), 
-    _lock(NULL), _name(name)
+  : _adapter(NULL), _adapter_dict(NULL), _name(name)
 {
   PyObject* pLoadmeStr = PyString_FromString(name);
   PyObject* pUserPolicyModule = PyImport_Import(pLoadmeStr);
@@ -56,18 +55,13 @@ PythonPolicy::PythonPolicy(const char* name)
   assert(pScriptAdapterModule);
   _adapter_dict = PyModule_GetDict(pScriptAdapterModule);
   assert(_adapter_dict);
-  // We want to keep a reference to it even if we decref 
-  // its containing module
+  // We want to keep a reference to it
   Py_INCREF(_adapter_dict);
   
   // Now takes the user-defined policy class from pUserPolicyDict
   PyObject* pPolicyClass = PyDict_GetItemString(pUserPolicyDict, name);
   assert(pPolicyClass); // FIXME needs stricter checking and exception throwing
     
-  // Save a reference to the global lock
-  _lock = PyDict_GetItemString(_adapter_dict, "_g_mutex");
-  assert(_lock);
-
   // Creates a new object of type ScriptAdapter :
   // takes init function from ScriptAdapter class
   PyObject* pAdapterClass = PyDict_GetItemString(_adapter_dict, "ScriptAdapter");
@@ -136,8 +130,10 @@ PythonPolicy::is_pre_emptive() const throw(UserInterruptException)
   wait_unlock();
   
   // Parse return value stored in global Python object
-  retval = PyDict_GetItemString(_adapter_dict, "_ret_val");
-  return PyBool_Check(retval);
+  retval = PyObject_CallMethod(_adapter, "get_return_value", NULL);
+  bool ret = PyObject_IsTrue(retval);
+  Py_DECREF(retval);
+  return ret;
 }
 
 
@@ -149,8 +145,10 @@ PythonPolicy::get_time_slice() const throw(UserInterruptException) {
   wait_unlock();
   
   // Parse return value stored in global Python object
-  retval = PyDict_GetItemString(_adapter_dict, "_ret_val");
+  retval = PyObject_CallMethod(_adapter, "get_return_value", NULL);
   long tmp = PyInt_AsLong(retval);
+  Py_DECREF(retval);
+
   return tmp < 0 ? numeric_limits<int>::max() : static_cast<int>(tmp);
 }
 
@@ -169,24 +167,24 @@ PythonPolicy::wait_unlock() const throw(UserInterruptException)
       usleep(WAIT_FOR); // hack'a'ton! magggggiccc nummmbeeerrrrrs!!
       Py_BLOCK_THREADS;
       
-      PyObject* retval = PyObject_CallMethod(_lock, "test", NULL);
-      still_locked = PyBool_Check(retval);
+      PyObject* retval = PyObject_CallMethod(_adapter, "test_lock", NULL);
+      assert(retval);
+      still_locked = PyObject_IsTrue(retval);
       Py_DECREF(retval);
 
-      if(i++ > WAIT_FOR*12) 
+      if(i++ > 12) /* waits for WAIT_FOR * 12 microseconds == 3 secs */
       {
 	PyThreadState_Clear(_save);
 	PyEval_RestoreThread(_save);
 	
 	//Py_UNBLOCK_THREADS;
-	
+
 	throw UserInterruptException("User-defined policy is " 
 				     "taking too long to terminate.");
 	}
     } 
   while(still_locked);
 
-  
   // What we should really do here:
   /* do {
      enable python threads

src/backend/pyloader/python_policy.hh

@@ -82,7 +82,6 @@ namespace sgpem
 
     PyObject* _adapter;
     PyObject* _adapter_dict;
-    PyObject* _lock;
 
     Glib::ustring _name;
   };