Port everything to work with Python 2.6 and (hopefully) 3.0.

Phew, this was harder than I expected, mostly because I 
noticed I never grokked metaclasses all that well. Now it's 
slightly better ;-).



git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@1344 3ecf2c5c-341e-0410-92b4-d18e462d057c

plugins/pyloader/Makefile.am

@@ -95,7 +95,6 @@ noinst_HEADERS += \
                src/python_cpu_policy_manager.hh
 
 share_PYTHON = \
-               src/Abstract.py \
                src/CPUPolicy.py \
                src/ScriptAdapter.py
 

plugins/pyloader/configure.ac

@@ -52,7 +52,7 @@ AM_GNU_GETTEXT_VERSION([0.17])
 
 dnl PYTHON_VERSION is declared precious by AC_PYTHON_DEVEL,
 dnl so don't use it here
-PY_VERSION=2.3
+PY_VERSION=2.6
 GTKMM_VERSION=2.8.0
 SGPEMV2_VERSION=1.0
 

plugins/pyloader/src/Abstract.py

@@ -1,96 +0,0 @@
-## @brief Defines a class to create abstract methods
-#
-# @author Ivo Timmermans
-# @date 2004/01/23
-# @version 1.1
-#
-# Example:
-# @code
-#    import Abstract;
-#    class Foo:
-#        __metaclass__ = Abstract.Metaclass
-#        foo = Abstract.AbstractMethod('foo')
-# @endcode
-class AbstractMethod (object):
-    ## @brief Constructor
-    #
-    # @param func name of the function (used when raising an
-    #    exception). Its type is str.
-    def __init__(self, func):
-        self._function = func
-
-    ## @brief Get callable object
-    #
-    # @return An instance of AbstractMethodHelper.
-    # This trickery is needed to get the name of the class for which
-    # an abstract method was requested, otherwise it would be
-    # sufficient to include a __call__ method in the AbstractMethod
-    # class itself.
-    def __get__(self, obj, type):
-        return self.AbstractMethodHelper(self._function, type)
-
-    ## @brief Abstract method helper class
-    #
-    # An AbstractMethodHelper instance is a callable object that
-    # represents an abstract method.
-    class AbstractMethodHelper (object):
-        def __init__(self, func, cls):
-            self._function = func
-            self._class = cls
-
-        ## @brief Call abstract method
-	# 
-	# Raises a TypeError, because abstract methods can not be
-	# called.
-        def __call__(self, *args, **kwargs):
-            raise TypeError('Abstract method `' + self._class.__name__ \
-                            + '.' + self._function + '\' called')
-
-## @brief Configure a new class to be abstract
-#
-# @author Ivo Timmermans
-# @date 2004/01/23
-# @version 1.1
-class Metaclass (type):
-    ## Configure a new class
-    #
-    # @param cls Class object
-    # @param name Name of the class
-    # @param bases All base classes for cls
-    def __init__(cls, name, bases, *args, **kwargs):
-        super(Metaclass, cls).__init__(cls, name, bases, *args, **kwargs)
-
-        # Detach cls.new() from class Metaclass, and make it a method
-        # of cls.
-        cls.__new__ = staticmethod(cls.new)
-
-        # Find all abstract methods, and assign the resulting list to
-        # cls.__abstractmethods__, so we can read that variable when a
-        # request for allocation (__new__) is done.
-        abstractmethods = []
-        ancestors = list(cls.__mro__)
-        ancestors.reverse()  # Start with __builtin__.object
-        for ancestor in ancestors:
-            for clsname, clst in ancestor.__dict__.items():
-                if isinstance(clst, AbstractMethod):
-                    abstractmethods.append(clsname)
-                else:
-                    if clsname in abstractmethods:
-                        abstractmethods.remove(clsname)
-
-        abstractmethods.sort()
-        setattr(cls, '__abstractmethods__', abstractmethods)
-
-    ## @brief Allocator for class cls
-    #
-    # @param self Class object for which an instance should be
-    # created.
-    # @param cls Same as self.
-    def new(self, cls):
-        if len(cls.__abstractmethods__):
-            raise NotImplementedError('Can\'t instantiate class `' + \
-                                      cls.__name__ + '\';\n' + \
-                                      'Abstract methods: ' + \
-                                      ", ".join(cls.__abstractmethods__))
-
-        return object.__new__(self)

plugins/pyloader/src/CPUPolicy.py

@@ -1,17 +1,11 @@
-from Abstract import *
+from abc import *
 import sgpem
                 
-## @brief This is the abstract class a user-defined policy
-# should inherit from
+## @brief The abstract base class needed for compatibility between 
+# Python 2.6 and Python 3.x.
 #  
-# This class also exposes the method sort(), which can be
-# used to easily sort the queue of ready process with a
-# user-defined given compare function.
-class CPUPolicy:
-    ## @var Avoid instantiation of an abstract class.
-    # @see Abstract.Metaclass
-    __metaclass__ = Metaclass
-
+# @see CPUPolicy
+class CPUPolicyBase(object):
     ## @brief Configure policy to initial values
     #
     # This is called just before a simulation starts, and is responsible
@@ -26,7 +20,9 @@ class CPUPolicy:
     # @endcode
     #
     # @see sgpem::Policy::get_parameters()
-    configure = AbstractMethod('configure')
+    @abstractmethod
+    def configure(self):
+        pass
 
     ## @brief Sort ready processes queue
     #
@@ -46,7 +42,9 @@ class CPUPolicy:
     # swap(positionA, positionB) and size().
     #
     # @see Policy::Policy::sort()
-    sort_queue = AbstractMethod('sort_queue')
+    @abstractmethod
+    def sort_queue(self, queue):
+        pass
 
     ## @brief Returns whether the policy wants to be preemptive,
     # other than by normal time slice termination
@@ -70,7 +68,9 @@ class CPUPolicy:
     # slice (or a process blocking/termination, of course) before
     # selecting a new running process, even if it has greater priority
     # than the current one
-    is_preemptive = AbstractMethod('is_preemptive')
+    @abstractmethod
+    def is_preemptive(self):
+        pass
 
     ## @brief Returns how long is a time-slice for this policy
     #
@@ -90,7 +90,9 @@ class CPUPolicy:
     #
     # @return -1 If the policy doesn't want to use time slices
     # @return 0+ To specify a time slice duration for this policy
-    get_time_slice = AbstractMethod('get_time_slice')
+    @abstractmethod
+    def get_time_slice(self):
+        pass
     
     ## @brief Returns the PolicyParameters instance you can use in
     # Policy::Policy::configure()
@@ -178,3 +180,18 @@ class CPUPolicy:
         # puts pivot in place
         queue.swap(i,b)
         return i
+
+
+        
+## @brief This is the abstract class a user-defined policy
+# should inherit from
+#
+# This class also exposes the method sort(), which can be
+# used to easily sort the queue of ready process with a
+# user-defined given compare function.
+#
+# @see CPUPolicyBase
+CPUPolicy = ABCMeta('CPUPolicy', (CPUPolicyBase, ), {})
+
+
+print (dir (CPUPolicy))

plugins/pyloader/src/builtin-policies/rr.py

@@ -21,7 +21,7 @@
 
 from CPUPolicy import CPUPolicy
 
-class rr(CPUPolicy) :
+class rr(CPUPolicy):
     """Round Robin scheduling policy
 
 This policy executes a thread for a given amount

plugins/pyloader/src/python_cpu_policy.cc

@@ -34,13 +34,39 @@ using namespace std;
 Glib::StaticRecMutex PythonCPUPolicy::_mtx = GLIBMM_STATIC_REC_MUTEX_INIT;
 
 
+// Convenience porting function for converting from Python 3.0
+// UCS-(2|4) strings to glib::ustring
+namespace sgpem
+{
+   static Glib::ustring 
+   PyString_AsString (PyObject* obj)
+   {
+      using ::PyString_AsString;
+      
+      Glib::ustring ret;
+      
+      PyObject     *str  = PyObject_Str (obj);
+      if (PyUnicode_Check (str))
+      {
+         PyObject *ustr = PyUnicode_AsUTF8String (str);
+         ret = PyBytes_AsString (ustr);
+         Py_DECREF (ustr);
+      }
+      else
+         ret = PyString_AS_STRING (str);
+      
+      Py_DECREF (str);
+      return ret;
+   }
+}
+
 // WARNING :  this class needs extensive and above all
 // *strong* exception checking / handling!
 
 PythonCPUPolicy::PythonCPUPolicy(const char* name) throw(MalformedPolicyException)
     : _upolicy_dict(NULL), _adapter(NULL), _name(name), _description()
 {
-  PyObject* pLoadmeStr = PyString_FromString(name);
+  PyObject* pLoadmeStr = PyUnicode_FromString (name);
   PyObject* pUserCPUPolicyModule = PyImport_Import(pLoadmeStr);
   Py_DECREF(pLoadmeStr);
 
@@ -52,7 +78,7 @@ PythonCPUPolicy::PythonCPUPolicy(const char* name) throw(MalformedPolicyExceptio
   assert(_upolicy_dict);
 
   // Loads ScriptAdapter module and get its dictionary
-  pLoadmeStr = PyString_FromString("ScriptAdapter");
+  pLoadmeStr = PyUnicode_FromString("ScriptAdapter");
   PyObject* pScriptAdapterModule = PyImport_Import(pLoadmeStr);
   Py_DECREF(pLoadmeStr);
   assert(pScriptAdapterModule);
@@ -68,7 +94,7 @@ PythonCPUPolicy::PythonCPUPolicy(const char* name) throw(MalformedPolicyExceptio
   // Retrieve a description for the policy using the __doc__ attribute
   PyObject* pDescriptionString = PyObject_GetAttrString(pCPUPolicyClass, "__doc__");
   if(pDescriptionString != Py_None)
-  	_description = PyString_AsString(pDescriptionString);
+  	_description = sgpem::PyString_AsString(pDescriptionString);
   Py_DECREF(pDescriptionString);
 
   // Creates a new object of type ScriptAdapter :
@@ -77,7 +103,7 @@ PythonCPUPolicy::PythonCPUPolicy(const char* name) throw(MalformedPolicyExceptio
   PyObject* pAdapterCtorParam = PyTuple_New(1);
   Py_INCREF(pCPUPolicyClass); // PyTuple_SetItem steals a reference
   PyTuple_SetItem(pAdapterCtorParam, 0, pCPUPolicyClass);
-  _adapter = PyInstance_New(pAdapterClass, pAdapterCtorParam, NULL);
+  _adapter = PyObject_CallObject((PyObject*) pAdapterClass, pAdapterCtorParam);
   Py_DECREF(pAdapterCtorParam);
 
   Py_DECREF(pScriptAdapterModule);
@@ -214,7 +240,7 @@ PythonCPUPolicy::get_time_slice() const throw(UserInterruptException, MalformedP
   // Parse return value stored in global Python object
   retval = PyObject_CallMethod(_adapter, const_cast<char*>("get_return_value"), NULL);
   assert(retval);
-  long tmp = PyInt_AsLong(retval);
+  long tmp = PyLong_AsLong(retval);
   Py_DECREF(retval);
 
   set_callback_policy(NULL);
@@ -269,12 +295,8 @@ PythonCPUPolicy::wait_unlock() const throw(UserInterruptException, MalformedPoli
   {
     if(pException != Py_None)
     {
-      PyObject* pExceptStr = PyObject_Str(pException);
-
       string msg = _("unhandled exception in user policy: ");
-      msg += PyString_AsString(pExceptStr);
-
-      Py_DECREF(pExceptStr);
+      msg += sgpem::PyString_AsString(pException);
       Py_DECREF(pException);
 
       throw MalformedPolicyException(msg);
@@ -316,11 +338,8 @@ PythonCPUPolicy::get_exception_information()
 
   if (pValue != NULL)
   {
-    PyObject* pValueStr = PyObject_Str(pValue);
-
-    msg = PyString_AsString(pValueStr);
-
-    Py_DECREF(pValueStr);
+    msg = sgpem::PyString_AsString(pValue) + "\n";
+    PyErr_PrintEx (false);
   }
   else
     msg = string(_("no available information for this error"));

plugins/pyloader/src/python_cpu_policy_manager.cc

@@ -70,8 +70,8 @@ PythonCPUPolicyManager::PythonCPUPolicyManager()
   // environment variables.
 
   GlobalPreferences& prefs = GlobalPreferences::get_instance();
-  Glib::ustring importdirs = "import sys\n"
-                             "sys.path[:0] = [ ";
+
+  Glib::ustring importdirs = "import sys; sys.path[:0] = [ ";
   for_each(prefs.get_policy_dirs().begin(),
            prefs.get_policy_dirs().end(),
            pol_dirs_concat(importdirs));