nitvm: clean the code and add some comments

Signed-off-by: Julien Pagès <julien.projet@gmail.com>

diff --git a/src/vm.nit b/src/vm.nit
index 3c8f048..bda1458 100644 (file)
--- a/src/vm.nit
+++ b/src/vm.nit
@@ -167,17 +167,15 @@ redef class MClass
                for parent in superclasses do
                        if parent.vtable == null then parent.make_vt(v)
                        
-                       # Get the number of introduced methods for this class
-                       var count = 0
-                       var min_visibility = public_visibility
-                       for p in parent.intro_mproperties(min_visibility) do
-                               if p isa MMethod then
-                                       count += 1
-                               end
+                       # Get the number of introduced methods and attributes for this class
+                       var methods = 0
+
+                       for p in parent.intro_mproperties(none_visibility) do
+                               if p isa MMethod then methods += 1
                        end
                        
                        ids.push(parent.vtable.id)
-                       nb_methods.push(count)
+                       nb_methods.push(methods)
                end
                
                # When all super-classes have their identifiers and vtables, allocate current one
@@ -188,7 +186,7 @@ redef class MClass
 
        # Allocate a single vtable
        #       ids : Array of superclasses identifiers
-       #       nb_methods : Array which contain the number of methods for each class in ids
+       #       nb_methods : Array which contain the number of introducted methods for each class in ids
        private fun allocate_vtable(v: VirtualMachine, ids: Array[Int], nb_methods: Array[Int])
        do
                vtable = new VTable
@@ -204,15 +202,12 @@ redef class MClass
                ids_total.push(vtable.id)
 
                var nb_methods_total = new Array[Int]
-               var count = 0
-               var min_visibility = public_visibility
-               for p in intro_mproperties(min_visibility) do
-                       if p isa MMethod then
-                               count += 1
-                       end
+               var methods = 0
+               for p in intro_mproperties(none_visibility) do
+                       if p isa MMethod then methods += 1
                end
                nb_methods_total.add_all(nb_methods)
-               nb_methods_total.push(count)
+               nb_methods_total.push(methods)
                
                vtable.internal_vtable = v.memory_manager.init_vtable(ids_total, nb_methods_total, vtable.mask)
        end
@@ -237,18 +232,7 @@ class VTable
 end
 
 redef class Instance
-       
        var vtable: nullable VTable
-
-       init(mt: MType)
-       do
-               mtype = mt
-
-               # An instance is associated to its class virtual table
-               if mt isa MClassType then
-                       vtable = mt.mclass.vtable
-               end
-       end
 end
 
 # Handle memory, used for allocate virtual table and associated structures
@@ -273,14 +257,14 @@ class MemoryManager
                int nb_classes = Array_of_Int_length(nb_methods);
                for(i = 0; i<nb_classes; i++) {
                        /* - One for each method of this class
-                       *  - One for the delta (pointer to attributes)
+                       *  - One for the delta (offset of this group of attributes in objects)
                        *  - One for the id 
                        */
                        total_size += Array_of_Int__index(nb_methods, i);
                        total_size += 2;
                }
 
-               // And the size of the perfect hashtable
+               // Add the size of the perfect hashtable
                total_size += mask+1;
                long unsigned int* vtable = malloc(sizeof(long unsigned int)*total_size);
                
@@ -298,7 +282,7 @@ class MemoryManager
                        /*
                                vtable[hv] contains a pointer to the group of introducted methods
                                For each superclasse we have in virtual table :
-                                       (id | delta (attributes) | introduced methods)
+                                       (id | delta | introduced methods)
                        */
                        int hv = mask & Array_of_Int__index(ids, i);