- implemented swap in schedulable_list.cc

git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@390 3ecf2c5c-341e-0410-92b4-d18e462d057c

src/backend/schedulable_list.cc

@@ -200,3 +200,39 @@ SchedulableList::has_same_objects(const SchedulableList& dx) const
 	return true;
 }
 
+
+void
+SchedulableList::swap(unsigned int positionA, unsigned int positionB) throw()
+{
+	if (positionA == positionB || positionA >= _list.size() || positionB >= _list.size())
+		return;
+
+	unsigned int min, max;
+	if (positionA < positionB)
+	{
+		min = positionA;
+		max = positionB;
+	}
+	else
+	{
+		min = positionB;
+		max = positionA;
+	}
+
+	list<SchedulableStatus>::iterator i1 = _list.begin();
+	list<SchedulableStatus>::iterator i2 = _list.begin();
+
+	//reach the first element;
+	for (uint f=0; f < min; f++)
+		i1++;
+	SchedulableStatus temp = *i1;
+
+	//reach the second element;
+	i2 = i1;
+	for (uint f=min; f < max; f++)
+		i2++;
+
+	*i1 = *i2;
+	*i2 = temp;
+}
+