- Finish implementing async setup for Python policies' access

- Correct method names for the Python policy (design problem?)
- Compiles, but can't run it on this machine. I'll test it later
(and I expect quite a lot of SIGSEGVs).


git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@382 3ecf2c5c-341e-0410-92b4-d18e462d057c

src/backend/dummy_policy.hh

@@ -50,6 +50,4 @@ namespace sgpem
 	
 }//~ namespace sgpem
 
-
-
-#endif
+#endif

src/backend/policy.hh

@@ -41,22 +41,21 @@ namespace sgpem
 	class SG_DLLEXPORT Policy 
 	{
 	public:
-		virtual ~Policy();
-				
-		virtual void			configure() = 0;
-		virtual void 			sort_queue(sgpem::Scheduler::event) const = 0;
-		int 					get_id() const;
-		virtual Glib::ustring 	get_description() const = 0;
-		virtual bool 			is_pre_emptive() const = 0;
-		virtual int				get_time_slice() const = 0;
-		virtual void 			set_time_slice(const int&) = 0;
-		
-		PolicyParameters& get_parameters();
-		
-		
+	  virtual ~Policy();
+	  
+	  virtual void			configure() = 0;
+	  virtual void 			sort_queue(sgpem::Scheduler::event) const = 0;
+	  int		  	        get_id() const;
+	  virtual Glib::ustring 	get_description() const = 0;
+	  virtual bool 			is_pre_emptive() const = 0;
+	  virtual int			get_time_slice() const = 0;
+	  virtual void 			set_time_slice(const int&) = 0;
+	  
+	  PolicyParameters& get_parameters();
+	  
 	protected:
-		PolicyParameters 	_parameters;
-		int			_id;
+	  PolicyParameters 	_parameters;
+	  int			_id;
 	};
 	
 }//~ namespace sgpem

src/backend/pyloader/Policy.py

@@ -7,5 +7,5 @@ class Policy:
     configure = AbstractMethod('configure')
     sort_queue = AbstractMethod('sort_queue')
     is_preemptive = AbstractMethod('is_preemptive')
-    is_time_sliced = AbstractMethod('is_time_sliced')
+    get_time_slice = AbstractMethod('get_time_slice')
     

src/backend/pyloader/ScriptAdapter.py

@@ -3,6 +3,10 @@ import sgpem
 
 _g_mutex = mutex.mutex()
 
+## @val 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
 #
@@ -29,6 +33,7 @@ class ScriptAdapter :
         
     def _wrap_configure(self):
         thread.start_new_thread(ScriptAdapter._wrap_configure_callback, (self,))
+        
     def _wrap_configure_callback(self):
         # call configure method
         self._policy.configure()
@@ -53,17 +58,15 @@ class ScriptAdapter :
         thread.start_new_thread(ScriptAdapter._wrap_is_preemptible_callback, (self,))
 
     def _wrap_is_preemptible_callback(self):
-        # FIXME : here we should return the call value
-        self._policy.is_preemptible()
+        _ret_val = self._policy.is_preemptible()
         _g_mutex.unlock()
     
-    def async_is_timesliced(self):
-        _g_mutex.lock(ScriptAdapter._wrap_is_timesliced, self)
+    def async_get_time_slice(self):
+        _g_mutex.lock(ScriptAdapter._wrap_get_time_slice, self)
 
-    def _wrap_is_timesliced(self):
-        thread.start_new_thread(ScriptAdapter._wrap_is_timesliced_callback, (self,))
+    def _wrap_get_time_slice(self):
+        thread.start_new_thread(ScriptAdapter._wrap_get_time_slice_callback, (self,))
 
-    def _wrap_is_timesliced_callback(self):
-        # FIXME : return value!
-        self._policy.is_timesliced()
+    def _wrap_get_time_slice_callback(self):
+        _ret_val = self._policy.get_time_slice()
         _g_mutex.unlock()

src/backend/pyloader/python_policy.cc

@@ -19,10 +19,159 @@
 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 
 #include "python_policy.hh"
+#include <unistd.h>
 using namespace sgpem;
 using namespace std;
 
-PythonPolicy::PythonPolicy()
+// WARNING :  this class needs extensive and above all
+// *strong* exception checking / handling!
+
+PythonPolicy::PythonPolicy(const char* name)
+  : _adapter(NULL), _adapter_dict(NULL), 
+    _lock(NULL), _name(name)
 {
+  PyObject* pLoadmeStr = PyString_FromString(name);
+  PyObject* pUserPolicyModule = PyImport_Import(pLoadmeStr);
+  Py_DECREF(pLoadmeStr);
+  
+  if( !pUserPolicyModule ) 
+  {
+    PyErr_Print(); // Error in import
+    // FIXME : don't exit abruptly, but fall back gracefully
+    exit(-1);
+  }
+  
+  // Dictionary with defined ``symbols'' for .pyc file
+  PyObject* pUserPolicyDict = PyModule_GetDict(pUserPolicyModule);
+  assert(pUserPolicyDict);
+
+  // Loads ScriptAdapter module and get its dictionary
+  pLoadmeStr = PyString_FromString("ScriptAdapter");
+  PyObject* pScriptAdapterModule = PyImport_Import(pLoadmeStr);
+  Py_DECREF(pLoadmeStr);
+  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
+  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");
+  PyObject* pAdapterCtorParam = PyTuple_New(1);
+  Py_INCREF(pPolicyClass); // PyTuple_SetItem steals a reference
+  PyTuple_SetItem(pAdapterCtorParam, 0, pPolicyClass);
+  _adapter = PyInstance_New(pAdapterClass, pAdapterCtorParam, NULL);
+  Py_DECREF(pAdapterCtorParam);
+  assert(_adapter);
+
+  Py_DECREF(pUserPolicyModule);
+  Py_DECREF(pScriptAdapterModule);
+
+  // And now, who's your daddy, huh?
 }
 
+
+PythonPolicy::~PythonPolicy()
+{
+  if(_adapter)      Py_DECREF(_adapter);
+  if(_adapter_dict) Py_DECREF(_adapter_dict);
+}
+
+
+void
+PythonPolicy::configure()
+{
+  PyObject* retval = PyObject_CallMethod(_adapter, "async_configure", NULL);
+  Py_DECREF(retval);
+  wait_unlock();
+}
+
+
+void
+PythonPolicy::sort_queue(Scheduler::event event) const 
+{
+  PyObject* pEvent = PyInt_FromLong(event);
+  PyObject* pMethodName = PyString_FromString("async_sort_queue");
+  PyObject* retval = PyObject_CallMethodObjArgs(_adapter, pMethodName, pEvent, NULL);
+  Py_DECREF(retval);
+  Py_DECREF(pMethodName);
+  Py_DECREF(pEvent);
+
+  wait_unlock();
+}
+
+
+Glib::ustring
+PythonPolicy::get_description() const 
+{
+  return _name;
+}
+
+
+bool
+PythonPolicy::is_pre_emptive() const {
+  PyObject* retval = PyObject_CallMethod(_adapter, "async_is_preemptive", NULL);
+  Py_DECREF(retval);
+  
+  wait_unlock();
+  
+  // Parse return value stored in global Python object
+  retval = PyDict_GetItemString(_adapter_dict, "_ret_val");
+  return static_cast<bool>(PyInt_AsLong(retval));
+}
+
+
+int
+PythonPolicy::get_time_slice() const {
+  PyObject* retval = PyObject_CallMethod(_adapter, "async_get_time_slice", NULL);
+  Py_DECREF(retval);
+  
+  wait_unlock();
+  
+  // Parse return value stored in global Python object
+  retval = PyDict_GetItemString(_adapter_dict, "_ret_val");
+  return static_cast<int>(PyInt_AsLong(retval));
+}
+
+
+void 
+PythonPolicy::set_time_slice(const int&) 
+{
+  throw "The design is wrong, and I shouldn't be called.";
+}
+
+    
+void
+PythonPolicy::wait_unlock() const 
+{
+  PyThreadState *_save;
+  Py_UNBLOCK_THREADS
+    sleep(5); // hack'a'ton! magggggiccc nummmbeeerrrrrs!!
+  
+  // What we should really do here:
+  /* do {
+     enable python threads
+     wait for some time...
+     disable python threads
+     ...check if user asked for interruption, reading a
+        syncronized variable...
+     ...if he has, break
+     ...else:
+           if the global lock is set:
+	      stay in this loop
+	   else:
+	      all's went okay, can exit loop
+  } */
+
+  Py_BLOCK_THREADS
+}

src/backend/pyloader/python_policy.hh

@@ -32,28 +32,37 @@
 
 namespace sgpem
 {
+  class PythonPolicy;
+  class PythonPolicyManager;
 	
-	class PythonPolicy;
-	class PythonPolicyManager;
+  class SG_DLLEXPORT PythonPolicy : public Policy
+  {
+  public:  
+    //only PythonPolicyManager can create a PythonPolicy object
+    friend class PythonPolicyManager;
 	
-	class SG_DLLEXPORT PythonPolicy : public Policy
-	{
-	public:  
-		//only PythonPolicyManager can create a PythonPolicy object
-		friend class PythonPolicyManager;
-		
-		void			configure() {}
-		void 			sort_queue(sgpem::Scheduler::event) const {}
-		Glib::ustring 	        get_description() const {}
-		bool 			is_pre_emptive() const {}
-		int			get_time_slice() const {}
-		void 			set_time_slice(const int&) {}
-								
-	private:		
-		PythonPolicy();
-		PythonPolicy(const PythonPolicy&);
-		PythonPolicy& operator=(const PythonPolicy&);
-	};
+    virtual ~PythonPolicy();
+	
+    void			configure();
+    void 			sort_queue(Scheduler::event) const;
+    Glib::ustring 	        get_description() const;
+    bool 			is_pre_emptive() const;
+    int                         get_time_slice() const;
+    void 			set_time_slice(const int&);
+    			
+  private:
+    PythonPolicy(const char* name);
+    PythonPolicy(const PythonPolicy&);
+    PythonPolicy& operator=(const PythonPolicy&);
+
+    void wait_unlock() const;
+
+    PyObject* _adapter;
+    PyObject* _adapter_dict;
+    PyObject* _lock;
+
+    Glib::ustring _name;
+  };
 
 }
 

src/backend/pyloader/python_policy_manager.cc

@@ -76,50 +76,7 @@ PythonPolicyManager::init()
 
   // FIXME : Hardcoded policy name
   char* policy_name = "fcfs";
-  PyObject* pLoadmeStr = PyString_FromString(policy_name);
-  PyObject* pUserPolicyModule = PyImport_Import(pLoadmeStr);
-  Py_DECREF(pLoadmeStr);
-  
-  if( !pUserPolicyModule ) 
-  {
-      PyErr_Print(); // Error in import
-      // FIXME : don't exit abruptly, but fall back gracefully
-      exit(-1);
-  }
-
-  // Dictionary with defined ``symbols'' for .pyc file
-  PyObject* pUserPolicyDict = PyModule_GetDict(pUserPolicyModule);
-  assert(pUserPolicyDict);
-
-  // Loads ScriptAdapter module and get its dictionary
-  pLoadmeStr = PyString_FromString("ScriptAdapter");
-  PyObject* pScriptAdapterModule = PyImport_Import(pLoadmeStr);
-  Py_DECREF(pLoadmeStr);
-  assert(pScriptAdapterModule);
-  PyObject* pScriptAdapterDict = PyModule_GetDict(pScriptAdapterModule);
-  assert(pScriptAdapterDict);
-  
-  // Now takes the user-defined policy class from pUserPolicyDict
-  PyObject* pPolicyClass = PyDict_GetItemString(pUserPolicyDict, policy_name);
-  assert(pPolicyClass); // FIXME needs stricter checking and exception throwing
-    
-  // Creates a new object of type ScriptAdapter :
-  // takes init function from ScriptAdapter class
-  PyObject* pAdapterClass = PyDict_GetItemString(pScriptAdapterDict, "ScriptAdapter");
-  PyObject* pAdapterCtorParam = PyTuple_New(1);
-  Py_INCREF(pPolicyClass); // PyTuple_SetItem steals a reference
-  PyTuple_SetItem(pAdapterCtorParam, 0, pPolicyClass);
-  PyObject* pAdapterObject = PyInstance_New(pAdapterClass, pAdapterCtorParam, NULL);
-    
-  // try code
-  PyObject_CallMethod(pAdapterObject, "async_configure", NULL);
-    
-  PyThreadState *_save;
-  Py_UNBLOCK_THREADS
-    sleep(5); // hack'a'ton! magggggiccc nummmbeeerrrrrs!!
-  
-  Py_BLOCK_THREADS
-      
-  // And now, who's your daddy, huh?
+  PythonPolicy policy(policy_name);
+  policy.configure();
 
 }

src/builtin-policies/fcfs.py

@@ -23,8 +23,8 @@ class fcfs(Policy) :
     def is_preemptive(self):
         return False
 
-    def is_time_sliced(self):
-        return False
+    def get_time_slice(self):
+        return -1
 
     def sort_queue(self, event, queue):
         # How am I supposed to sort that mess??