Lua: add support of closures to the state cloner

[simgrid.git] / src / bindings / lua / lua_state_cloner.c

diff --git a/src/bindings/lua/lua_state_cloner.c b/src/bindings/lua/lua_state_cloner.c
index 25d6b74..4e35f18 100644 (file)
--- a/src/bindings/lua/lua_state_cloner.c
+++ b/src/bindings/lua/lua_state_cloner.c
@@ -15,10 +15,11 @@
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(lua_state_cloner, lua, "Lua state management");
 
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(lua_state_cloner, lua, "Lua state management");
 

-static lua_State* sglua_get_father(lua_State* L);
-static int l_get_from_father(lua_State* L);
+static void sglua_add_maestro_table(lua_State* L, int index, void* maestro_table_ptr);
+static void* sglua_get_maestro_table_ptr(lua_State* L, int index);
+static void sglua_get_table_by_ptr(lua_State* L, void* table_ptr);
+static int l_get_from_maestro(lua_State* L);

 
 

-static void sglua_move_value_impl(lua_State* src, lua_State* dst, const char* name);

 static void sglua_copy_nil(lua_State* src, lua_State* dst);
 static void sglua_copy_number(lua_State* src, lua_State* dst);
 static void sglua_copy_boolean(lua_State* src, lua_State* dst);
 static void sglua_copy_nil(lua_State* src, lua_State* dst);
 static void sglua_copy_number(lua_State* src, lua_State* dst);
 static void sglua_copy_boolean(lua_State* src, lua_State* dst);


@@ -30,78 +31,118 @@ static void sglua_copy_userdata(lua_State* src, lua_State* dst);
 static void sglua_copy_thread(lua_State* src, lua_State* dst);
 
 /**
 static void sglua_copy_thread(lua_State* src, lua_State* dst);
 
 /**

- * @brief Returns the father of a state, i.e. the state that created it.
+ * @brief Adds a reference to a maestro table to the list of known maestro
+ * tables of a state.
+ *
+ * TODO identify maestro's tables with my own IDs instead of pointers
+ * to Lua internals
+ *
+ * @param L a state (can be maestro itself)
+ * @param index index of the copy of the maestro table in the stack of L
+ * @param maestro_table_ptr pointer to the original table in maestro's world
+ */
+void sglua_add_maestro_table(lua_State* L, int index, void* maestro_table_ptr) {
+
+  /* we will set both [ptr] -> table and [table] -> ptr */
+
+                                  /* ... */
+  lua_pushvalue(L, index);
+                                  /* ... table */
+  lua_pushstring(L, "simgrid.maestro_tables");
+                                  /* ... table "simgrid.maestro_tables" */
+  lua_rawget(L, LUA_REGISTRYINDEX);
+                                  /* ... table maestrotbs */
+  lua_pushvalue(L, -2);
+                                  /* ... table maestrotbs table */
+  lua_pushlightuserdata(L, maestro_table_ptr);
+                                  /* ... table maestrotbs table tableptr */
+  lua_pushvalue(L, -1);
+                                  /* ... table maestrotbs table tableptr tableptr */
+  lua_pushvalue(L, -3);
+                                  /* ... table maestrotbs table tableptr tableptr table */
+  lua_settable(L, -5);
+                                  /* ... table maestrotbs table tableptr */
+  lua_settable(L, -3);
+                                  /* ... table maestrotbs */
+  lua_pop(L, 2);
+                                  /* ... */
+}
+
+/**
+ * @brief For a table in the stack of L, returns a pointer that identifies the
+ * same table in in maestro's world.

  * @param L a Lua state
  * @param L a Lua state

- * @return its father, or NULL if the state was not created by sglua_clone_state()
+ * @param index index of a table in the stack of L
+ * @return a pointer to maestro's copy of this table, or NULL if this table
+ * did not come from maestro

  */
  */

-static lua_State* sglua_get_father(lua_State* L) {
+static void* sglua_get_maestro_table_ptr(lua_State* L, int index) {

 
 

+  void* maestro_table_ptr = NULL;

                                   /* ... */
                                   /* ... */

-  lua_pushstring(L, "simgrid.father");
-                                  /* ... "simgrid.father" */
+  lua_pushvalue(L, index);
+                                  /* ... table */
+  lua_pushstring(L, "simgrid.maestro_tables");
+                                  /* ... table "simgrid.maestro_tables" */

   lua_rawget(L, LUA_REGISTRYINDEX);
   lua_rawget(L, LUA_REGISTRYINDEX);

-                                  /* ... father */
-  lua_State* father = lua_touserdata(L, -1);
-  lua_pop(L, 1);
+                                  /* ... table maestrotbs */
+  lua_pushvalue(L, -2);
+                                  /* ... table maestrotbs table */
+  lua_gettable(L, -2);
+                                  /* ... table maestrotbs tableptr/nil */
+  if (!lua_isnil(L, -1)) {
+                                  /* ... table maestrotbs tableptr */
+    maestro_table_ptr = (void*) lua_topointer(L, -1);
+  }
+
+  lua_pop(L, 3);

                                   /* ... */
                                   /* ... */

-  return father;
+  return maestro_table_ptr;

 }
 
 /**
 }
 
 /**

- * @brief Pops a value from a state and pushes it onto the stack of another
- * state.
+ * @brief Pushes a table knowing a pointer to maestro's copy of this table.

  *
  *

- * @param src the source state
- * @param dst the destination state
+ * Pushes nil if L does not know this table in maestro.
+ *
+ * @param L a Lua state
+ * @param maestro_table_ptr pointer that identifies a table in maestro's world

  */
  */

-void sglua_move_value(lua_State* src, lua_State* dst) {
-
-  if (src != dst) {
+static void sglua_get_table_by_ptr(lua_State* L, void* maestro_table_ptr) {

 
 

-    /* get the list of visited tables from father at index 1 of dst */
-                                  /* src: ... value
-                                     dst: ... */
-    lua_getfield(dst, LUA_REGISTRYINDEX, "simgrid.father_visited_tables");
-                                  /* dst: ... visited */
-    lua_insert(dst, 1);
-                                  /* dst: visited ... */
-
-    sglua_move_value_impl(src, dst, sglua_tostring(src, -1));
-                                  /* src: ...
-                                     dst: visited ... value */
-    lua_remove(dst, 1);
-                                  /* dst: ... value */
-    sglua_stack_dump("src after xmove: ", src);
-    sglua_stack_dump("dst after xmove: ", dst);
-  }
+                                  /* ... */
+  lua_pushstring(L, "simgrid.maestro_tables");
+                                  /* ... "simgrid.maestro_tables" */
+  lua_rawget(L, LUA_REGISTRYINDEX);
+                                  /* ... maestrotbs */
+  lua_pushlightuserdata(L, maestro_table_ptr);
+                                  /* ... maestrotbs tableptr */
+  lua_gettable(L, -2);
+                                  /* ... maestrotbs table/nil */
+  lua_remove(L, -2);
+                                  /* ... table/nil */

 }
 
 /**
  * @brief Pops a value from the stack of a source state and pushes it on the
  * stack of another state.
 }
 
 /**
  * @brief Pops a value from the stack of a source state and pushes it on the
  * stack of another state.

+ * If the value is a table, its content is copied recursively.

  *
  *

- * If the value is a table, its content is copied recursively. To avoid cycles,
- * a table of previously visited tables must be present at index 1 of dst.
- * Its keys are pointers to visited tables in src and its values are the tables
- * already built.
- *
- * TODO: add support of closures
+ * This function is similar to lua_xmove() but it allows to move a value
+ * between two different global states.

  *
  *

- * @param src the source state
- * @param dst the destination state, with a list of visited tables at index 1
- * @param name a name describing the value (for debugging purposes)
+ * @param src the source state (not necessarily maestro)
+ * @param dst the destination state

  */
  */

-static void sglua_move_value_impl(lua_State* src, lua_State *dst, const char* name) {
+void sglua_move_value(lua_State* src, lua_State *dst) {

 
   luaL_checkany(src, -1);                  /* check the value to copy */
 
   luaL_checkany(src, -1);                  /* check the value to copy */

-  luaL_checktype(dst, 1, LUA_TTABLE);      /* check the presence of a table of
-                                              previously visited tables */

 
   int indent = (lua_gettop(dst) - 1) * 6;
 
   int indent = (lua_gettop(dst) - 1) * 6;

-  XBT_DEBUG("%sCopying data %s", sglua_get_spaces(indent), name);
+  XBT_DEBUG("%sCopying data %s", sglua_get_spaces(indent), sglua_tostring(src, -1));

 
   sglua_stack_dump("src before copying a value (should be ... value): ", src);
 
   sglua_stack_dump("src before copying a value (should be ... value): ", src);

-  sglua_stack_dump("dst before copying a value (should be visited ...): ", dst);
+  sglua_stack_dump("dst before copying a value (should be ...): ", dst);

 
   switch (lua_type(src, -1)) {
 
 
   switch (lua_type(src, -1)) {
 


@@ -149,7 +190,7 @@ static void sglua_move_value_impl(lua_State* src, lua_State *dst, const char* na
   XBT_DEBUG("%sData copied", sglua_get_spaces(indent));
 
   sglua_stack_dump("src after copying a value (should be ...): ", src);
   XBT_DEBUG("%sData copied", sglua_get_spaces(indent));
 
   sglua_stack_dump("src after copying a value (should be ...): ", src);

-  sglua_stack_dump("dst after copying a value (should be visited ... value): ", dst);
+  sglua_stack_dump("dst after copying a value (should be ... value): ", dst);

 }
 
 /**
 }
 
 /**


@@ -179,6 +220,11 @@ static void sglua_copy_boolean(lua_State* src, lua_State* dst) {
   lua_pushboolean(dst, lua_toboolean(src, -1));
 }
 
   lua_pushboolean(dst, lua_toboolean(src, -1));
 }
 

+/**
+ * @brief Copies the string value on the top of src to the top of dst.
+ * @param src source state
+ * @param dst destination state
+ */

 static void sglua_copy_string(lua_State* src, lua_State* dst) {
 
   /* no worries about memory: lua_pushstring makes a copy */
 static void sglua_copy_string(lua_State* src, lua_State* dst) {
 
   /* no worries about memory: lua_pushstring makes a copy */


@@ -190,133 +236,128 @@ static void sglua_copy_string(lua_State* src, lua_State* dst) {
  *
  * A deep copy of the table is made. If the table has a metatable, the
  * metatable is also copied.
  *
  * A deep copy of the table is made. If the table has a metatable, the
  * metatable is also copied.

- * If the table is already known by the destination state, nothing is
- * done.
+ * If the table is already known by the destination state, it is not copied
+ * again.

  *
  * @param src source state
  * @param dst destination state
  */
 static void sglua_copy_table(lua_State* src, lua_State* dst) {
 
  *
  * @param src source state
  * @param dst destination state
  */
 static void sglua_copy_table(lua_State* src, lua_State* dst) {
 

-  int indent = (lua_gettop(dst) - 1) * 6  + 2;
-
-  /* first register the table in the source state itself */
-  lua_getfield(src, LUA_REGISTRYINDEX, "simgrid.visited_tables");
-                              /* src: ... table visited */
-  lua_pushvalue(src, -2);
-                              /* src: ... table visited table */
-  lua_pushlightuserdata(src, (void*) lua_topointer(src, -1));
-                              /* src: ... table visited table psrctable */
-  lua_pushvalue(src, -1);
-                              /* src: ... table visited table psrctable psrctable */
-  lua_pushvalue(src, -3);
-                              /* src: ... table visited table psrctable psrctable table */
-  lua_settable(src, -5);
-                              /* src: ... table visited table psrctable */
-  lua_settable(src, -3);
-                              /* src: ... table visited */
-  lua_pop(src, 1);
-                              /* src: ... table */
-
-  /* see if this table was already known by dst */
-  lua_pushlightuserdata(dst, (void*) lua_topointer(src, -1));
-                              /* dst: visited ... psrctable */
-  lua_gettable(dst, 1);
-                              /* dst: visited ... table/nil */
-  if (lua_istable(dst, -1)) {
-    XBT_DEBUG("%sNothing to do: table already visited (%p)",
-        sglua_get_spaces(indent), lua_topointer(src, -1));
-                              /* dst: visited ... table */
+                                  /* src: ... table
+                                     dst: ... */
+  int indent = lua_gettop(dst) * 6  + 2;
+
+  /* get from maestro the pointer that identifies this table */
+  void* table_ptr = sglua_get_maestro_table_ptr(src, -1);
+  if (table_ptr == NULL) {
+    /* the table didn't come from maestro: nevermind, use the pointer of src */
+    table_ptr = (void*) lua_topointer(src, -1);
+
+    if (!sglua_is_maestro(src)) {
+      XBT_DEBUG("%sMaestro does not know this table",
+          sglua_get_spaces(indent));
+    }
+  }
+
+  if (sglua_is_maestro(src)) {
+    /* register the table in maestro itself */
+    XBT_DEBUG("%sKeeping track of this table in maestro itself",
+        sglua_get_spaces(indent));
+    sglua_add_maestro_table(src, -1, table_ptr);
+    xbt_assert(sglua_get_maestro_table_ptr(src, -1) == table_ptr);
+  }
+
+  /* to avoid infinite recursion, see if this table is already known by dst */
+  sglua_get_table_by_ptr(dst, table_ptr);
+                                  /* dst: ... table/nil */
+  if (!lua_isnil(dst, -1)) {
+    XBT_DEBUG("%sNothing to do: table already known (%p)",
+        sglua_get_spaces(indent), table_ptr);
+                                  /* dst: ... table */

   }
   else {
     XBT_DEBUG("%sFirst visit of this table (%p)", sglua_get_spaces(indent),
   }
   else {
     XBT_DEBUG("%sFirst visit of this table (%p)", sglua_get_spaces(indent),

-        lua_topointer(src, -1));
-                              /* dst: visited ... nil */
+        table_ptr);
+                                  /* dst: ... nil */

     lua_pop(dst, 1);
     lua_pop(dst, 1);

-                              /* dst: visited ... */
+                                  /* dst: ... */

 
     /* first visit: create the new table in dst */
     lua_newtable(dst);
 
     /* first visit: create the new table in dst */
     lua_newtable(dst);

-                              /* dst: visited ... table */
-
-    /* mark the table as visited right now to avoid infinite recursion */
-    lua_pushlightuserdata(dst, (void*) lua_topointer(src, -1));
-                              /* dst: visited ... table psrctable */
-    lua_pushvalue(dst, -2);
-                              /* dst: visited ... table psrctable table */
-    lua_pushvalue(dst, -1);
-                              /* dst: visited ... table psrctable table table */
-    lua_pushvalue(dst, -3);
-                              /* dst: visited ... table psrctable table table psrctable */
-    lua_settable(dst, 1);
-                              /* dst: visited ... table psrctable table */
-    lua_settable(dst, 1);
-                              /* dst: visited ... table */
-    XBT_DEBUG("%sTable marked as visited", sglua_get_spaces(indent));
-
-    sglua_stack_dump("dst after marking the table as visited (should be visited ... table): ", dst);
+                                  /* dst: ... table */
+
+    /* mark the table as known right now to avoid infinite recursion */
+    sglua_add_maestro_table(dst, -1, table_ptr);
+    /* FIXME: we may have added a table with a non-maestro pointer, is this a
+       problem? */
+    XBT_DEBUG("%sTable marked as known", sglua_get_spaces(indent));
+    xbt_assert(sglua_get_maestro_table_ptr(dst, -1) == table_ptr);
+
+    sglua_stack_dump("dst after marking the table as known (should be ... table): ", dst);

 
     /* copy the metatable if any */
     int has_meta_table = lua_getmetatable(src, -1);
 
     /* copy the metatable if any */
     int has_meta_table = lua_getmetatable(src, -1);

-                              /* src: ... table mt? */
+                                  /* src: ... table mt? */

     if (has_meta_table) {
     if (has_meta_table) {

-      XBT_DEBUG("%sCopying metatable", sglua_get_spaces(indent));
-                              /* src: ... table mt */
+      XBT_DEBUG("%sCopying the metatable", sglua_get_spaces(indent));
+                                  /* src: ... table mt */

       sglua_copy_table(src, dst);
       sglua_copy_table(src, dst);

-                              /* dst: visited ... table mt */
+                                  /* dst: ... table mt */

       lua_pop(src, 1);
       lua_pop(src, 1);

-                              /* src: ... table */
+                                  /* src: ... table */

       lua_setmetatable(dst, -2);
       lua_setmetatable(dst, -2);

-                              /* dst: visited ... table */
+                                  /* dst: ... table */

     }
     else {
     }
     else {

+                                  /* src: ... table */

       XBT_DEBUG("%sNo metatable", sglua_get_spaces(indent));
     }
 
     sglua_stack_dump("src before traversing the table (should be ... table): ", src);
       XBT_DEBUG("%sNo metatable", sglua_get_spaces(indent));
     }
 
     sglua_stack_dump("src before traversing the table (should be ... table): ", src);

-    sglua_stack_dump("dst before traversing the table (should be visited ... table): ", dst);
+    sglua_stack_dump("dst before traversing the table (should be ... table): ", dst);

 
     /* traverse the table of src and copy each element */
     lua_pushnil(src);
 
     /* traverse the table of src and copy each element */
     lua_pushnil(src);

-                              /* src: ... table nil */
+                                  /* src: ... table nil */

     while (lua_next(src, -2) != 0) {
     while (lua_next(src, -2) != 0) {

-                              /* src: ... table key value */
+                                  /* src: ... table key value */

 
       XBT_DEBUG("%sCopying table element %s", sglua_get_spaces(indent),
           sglua_keyvalue_tostring(src, -2, -1));
 
       sglua_stack_dump("src before copying table element (should be ... table key value): ", src);
 
       XBT_DEBUG("%sCopying table element %s", sglua_get_spaces(indent),
           sglua_keyvalue_tostring(src, -2, -1));
 
       sglua_stack_dump("src before copying table element (should be ... table key value): ", src);

-      sglua_stack_dump("dst before copying table element (should be visited ... table): ", dst);
+      sglua_stack_dump("dst before copying table element (should be ... table): ", dst);

 
       /* copy the key */
       lua_pushvalue(src, -2);
 
       /* copy the key */
       lua_pushvalue(src, -2);

-                              /* src: ... table key value key */
+                                  /* src: ... table key value key */

       indent += 2;
       XBT_DEBUG("%sCopying the key part of the table element",
           sglua_get_spaces(indent));
       indent += 2;
       XBT_DEBUG("%sCopying the key part of the table element",
           sglua_get_spaces(indent));

-      sglua_move_value_impl(src, dst, sglua_tostring(src, -1));
-                              /* src: ... table key value
-                                 dst: visited ... table key */
+      sglua_move_value(src, dst);
+                                  /* src: ... table key value
+                                     dst: ... table key */

       XBT_DEBUG("%sCopied the key part of the table element",
           sglua_get_spaces(indent));
 
       /* copy the value */
       XBT_DEBUG("%sCopying the value part of the table element",
           sglua_get_spaces(indent));
       XBT_DEBUG("%sCopied the key part of the table element",
           sglua_get_spaces(indent));
 
       /* copy the value */
       XBT_DEBUG("%sCopying the value part of the table element",
           sglua_get_spaces(indent));

-      sglua_move_value_impl(src, dst, sglua_tostring(src, -1));
-                              /* src: ... table key
-                                 dst: visited ... table key value */
+      sglua_move_value(src, dst);
+                                  /* src: ... table key
+                                     dst: ... table key value */

       XBT_DEBUG("%sCopied the value part of the table element",
           sglua_get_spaces(indent));
       indent -= 2;
 
       /* set the table element */
       lua_settable(dst, -3);
       XBT_DEBUG("%sCopied the value part of the table element",
           sglua_get_spaces(indent));
       indent -= 2;
 
       /* set the table element */
       lua_settable(dst, -3);

-                              /* dst: visited ... table */
+                                  /* dst: ... table */

 
       /* the key stays on top of src for next iteration */
       sglua_stack_dump("src before next iteration (should be ... table key): ", src);
 
       /* the key stays on top of src for next iteration */
       sglua_stack_dump("src before next iteration (should be ... table key): ", src);

-      sglua_stack_dump("dst before next iteration (should be visited ... table): ", dst);
+      sglua_stack_dump("dst before next iteration (should be ... table): ", dst);

 
       XBT_DEBUG("%sTable element copied", sglua_get_spaces(indent));
     }
 
       XBT_DEBUG("%sTable element copied", sglua_get_spaces(indent));
     }


@@ -328,7 +369,7 @@ static void sglua_copy_table(lua_State* src, lua_State* dst) {
  * @brief Copies the function on the top of src to the top of dst.
  *
  * It can be a Lua function or a C function.
  * @brief Copies the function on the top of src to the top of dst.
  *
  * It can be a Lua function or a C function.

- * Copying upvalues is not implemented yet (TODO).
+ * Copying upvalues is not implemented yet.

  *
  * @param src source state
  * @param dst destination state
  *
  * @param src source state
  * @param dst destination state


@@ -336,9 +377,33 @@ static void sglua_copy_table(lua_State* src, lua_State* dst) {
 static void sglua_copy_function(lua_State* src, lua_State* dst) {
 
   if (lua_iscfunction(src, -1)) {
 static void sglua_copy_function(lua_State* src, lua_State* dst) {
 
   if (lua_iscfunction(src, -1)) {

-    /* it's a C function: just copy the pointer */
-    lua_CFunction f = lua_tocfunction(src, -1);
-    lua_pushcfunction(dst, f);
+    /* it's a C function */
+
+    XBT_DEBUG("It's a C function");
+    sglua_stack_dump("src before copying upvalues: ", src);
+
+    /* get the function pointer */
+    int function_index = lua_gettop(src);
+    lua_CFunction f = lua_tocfunction(src, function_index);
+
+    /* copy the upvalues */
+    int i = 0;
+    const char* upvalue_name = NULL;
+    do {
+      i++;
+      upvalue_name = lua_getupvalue(src, function_index, i);
+
+      if (upvalue_name != NULL) {
+        XBT_DEBUG("Upvalue %s", upvalue_name);
+        sglua_move_value(src, dst);
+      }
+    } while (upvalue_name != NULL);
+
+    sglua_stack_dump("src before copying pointer: ", src);
+
+    /* set the function */
+    lua_pushcclosure(dst, f, i - 1);
+    XBT_DEBUG("Function pointer copied");

   }
   else {
     /* it's a Lua function: dump it from src */
   }
   else {
     /* it's a Lua function: dump it from src */


@@ -379,15 +444,15 @@ static void sglua_copy_lightuserdata(lua_State* src, lua_State* dst) {
  */
 static void sglua_copy_userdata(lua_State* src, lua_State* dst) {
 
  */
 static void sglua_copy_userdata(lua_State* src, lua_State* dst) {
 

-  int indent = (lua_gettop(dst) - 1) * 6  + 2;
+  int indent = lua_gettop(dst) * 6  + 2;

 
   /* copy the data */
                                   /* src: ... udata
 
   /* copy the data */
                                   /* src: ... udata

-                                     dst: visited ... */
+                                     dst: ... */

   size_t size = lua_objlen(src, -1);
   void* src_block = lua_touserdata(src, -1);
   void* dst_block = lua_newuserdata(dst, size);
   size_t size = lua_objlen(src, -1);
   void* src_block = lua_touserdata(src, -1);
   void* dst_block = lua_newuserdata(dst, size);

-                                  /* dst: visited ... udata */
+                                  /* dst: ... udata */

   memcpy(dst_block, src_block, size);
 
   /* copy the metatable if any */
   memcpy(dst_block, src_block, size);
 
   /* copy the metatable if any */


@@ -397,51 +462,13 @@ static void sglua_copy_userdata(lua_State* src, lua_State* dst) {
     XBT_DEBUG("%sCopying metatable of userdata (%p)",
         sglua_get_spaces(indent), lua_topointer(src, -1));
                                   /* src: ... udata mt */
     XBT_DEBUG("%sCopying metatable of userdata (%p)",
         sglua_get_spaces(indent), lua_topointer(src, -1));
                                   /* src: ... udata mt */

-    lua_State* father = sglua_get_father(dst);
-
-    if (father != NULL && src != father && sglua_get_father(src) == father) {
-      XBT_DEBUG("%sGet the metatable from my father",
-          sglua_get_spaces(indent));
-      /* I don't want the metatable of src, I want the father's copy of the
-         same metatable */
-
-      /* get from src the pointer to the father's copy of this metatable */
-      lua_pushstring(src, "simgrid.father_visited_tables");
-                                  /* src: ... udata mt "simgrid.visited_tables" */
-      lua_rawget(src, LUA_REGISTRYINDEX);
-                                  /* src: ... udata mt visited */
-      lua_pushvalue(src, -2);
-                                  /* src: ... udata mt visited mt */
-      lua_gettable(src, -2);
-                                  /* src: ... udata mt visited pfathermt */
-
-      /* copy the metatable from the father world into dst */
-      lua_pushstring(father, "simgrid.visited_tables");
-                                  /* father: ... "simgrid.visited_tables" */
-      lua_rawget(father, LUA_REGISTRYINDEX);
-                                  /* father: ... visited */
-      lua_pushlightuserdata(father, (void*) lua_topointer(src, -1));
-                                  /* father: ... visited pfathermt */
-      lua_gettable(father, -2);
-                                  /* father: ... visited mt */
-      sglua_move_value_impl(father, dst, "(father metatable)");
-                                  /* father: ... visited
-                                     dst: visited ... udata mt */
-      lua_pop(father, 1);
-                                  /* father: ... */
-      lua_pop(src, 3);
+    sglua_copy_table(src, dst);
+                                  /* src: ... udata mt
+                                     dst: ... udata mt */
+    lua_pop(src, 1);

                                   /* src: ... udata */
                                   /* src: ... udata */

-
-      /* TODO make helper functions for this kind of operations */
-    }
-    else {
-      XBT_DEBUG("%sI have no father", sglua_get_spaces(indent));
-      sglua_move_value_impl(src, dst, "metatable");
-                                  /* src: ... udata
-                                     dst: visited ... udata mt */
-    }

     lua_setmetatable(dst, -2);
     lua_setmetatable(dst, -2);

-                                  /* dst: visited ... udata */
+                                  /* dst: ... udata */

 
     XBT_DEBUG("%sMetatable of userdata copied", sglua_get_spaces(indent));
   }
 
     XBT_DEBUG("%sMetatable of userdata copied", sglua_get_spaces(indent));
   }


@@ -453,28 +480,27 @@ static void sglua_copy_userdata(lua_State* src, lua_State* dst) {
 }
 
 /**
 }
 
 /**

- * @brief This operation is not supported (yet?) so this function pushes nil.
+ * @brief This operation is not supported (yet?) so it just pushes nil.

  *
  * @param src source state
  * @param dst destination state
  */
 static void sglua_copy_thread(lua_State* src, lua_State* dst) {
 
  *
  * @param src source state
  * @param dst destination state
  */
 static void sglua_copy_thread(lua_State* src, lua_State* dst) {
 

-  XBT_WARN("Cannot copy a thread from the source state.");
+  XBT_WARN("Copying a thread from another state is not implemented (yet?).");

   lua_pushnil(dst);
 }
 
 /**
   lua_pushnil(dst);
 }
 
 /**

- * @brief Copies a global value or a registry value from the father state.
+ * @brief Copies a global value or a registry value from the maestro state.

  *
  *

- * The state L must have a father, i.e. it should have been created by
- * clone_lua_state().
+ * The state L must have been created by sglua_clone_maestro_state().

  * This function is meant to be an __index metamethod.
  * Consequently, it assumes that the stack has two elements:
  * a table (either the environment or the registry of L) and the string key of
  * a value that does not exist yet in this table. It copies the corresponding
  * This function is meant to be an __index metamethod.
  * Consequently, it assumes that the stack has two elements:
  * a table (either the environment or the registry of L) and the string key of
  * a value that does not exist yet in this table. It copies the corresponding

- * value from the father state and pushes it on the stack of L.
- * If the value does not exist in the father state either, nil is pushed.
+ * value from maestro and pushes it on the stack of L.
+ * If the value does not exist in maestro state either, nil is pushed.

  *
  * TODO: make this function thread safe. If the simulation runs in parallel,
  * several simulated processes may trigger this __index metamethod at the same
  *
  * TODO: make this function thread safe. If the simulation runs in parallel,
  * several simulated processes may trigger this __index metamethod at the same


@@ -483,12 +509,12 @@ static void sglua_copy_thread(lua_State* src, lua_State* dst) {
  * @param L the current state
  * @return number of return values pushed (always 1)
  */
  * @param L the current state
  * @return number of return values pushed (always 1)
  */

-static int l_get_from_father(lua_State *L) {
+static int l_get_from_maestro(lua_State *L) {

 
   /* check the arguments */
   luaL_checktype(L, 1, LUA_TTABLE);
   const char* key = luaL_checkstring(L, 2);
 
   /* check the arguments */
   luaL_checktype(L, 1, LUA_TTABLE);
   const char* key = luaL_checkstring(L, 2);

-                                               /* L:      table key */
+                                  /* L:      table key */

   XBT_DEBUG("__index of '%s' begins", key);
 
   /* want a global or a registry value? */
   XBT_DEBUG("__index of '%s' begins", key);
 
   /* want a global or a registry value? */


@@ -496,43 +522,27 @@ static int l_get_from_father(lua_State *L) {
   if (lua_equal(L, 1, LUA_REGISTRYINDEX)) {
     /* registry */
     pseudo_index = LUA_REGISTRYINDEX;
   if (lua_equal(L, 1, LUA_REGISTRYINDEX)) {
     /* registry */
     pseudo_index = LUA_REGISTRYINDEX;

-    XBT_DEBUG("Will get the value from the registry of the father");
+    XBT_DEBUG("Will get the value from the registry of maestro");

   }
   else {
     /* global */
     pseudo_index = LUA_GLOBALSINDEX;
   }
   else {
     /* global */
     pseudo_index = LUA_GLOBALSINDEX;

-    XBT_DEBUG("Will get the value from the globals of the father");
+    XBT_DEBUG("Will get the value from the globals of maestro");

   }
 
   /* get the father */
   }
 
   /* get the father */

-  lua_State* father = sglua_get_father(L);
+  lua_State* maestro = sglua_get_maestro();

 
 

-  if (father == NULL) {
-    XBT_WARN("This state has no father");
-    lua_pop(L, 3);
-    lua_pushnil(L);
-    return 1;
-  }

                                   /* L:      table key */
 
                                   /* L:      table key */
 

-  /* get the list of visited tables */
-  lua_pushstring(L, "simgrid.father_visited_tables");
-                                  /* L:      table key "simgrid.father_visited_tables" */
-  lua_rawget(L, LUA_REGISTRYINDEX);
-                                  /* L:      table key visited */
-  lua_insert(L, 1);
-                                  /* L:      visited table key */
-
-  /* get the value from the father */
-  lua_getfield(father, pseudo_index, key);
-                                  /* father: ... value */
+  /* get the value from maestro */
+  lua_getfield(maestro, pseudo_index, key);
+                                  /* maestro: ... value */

 
   /* push the value onto the stack of L */
 
   /* push the value onto the stack of L */

-  sglua_move_value_impl(father, L, key);
-                                  /* father: ...
-                                     L:      visited table key value */
-  lua_remove(L, 1);
-                                  /* L:      table key value */
+  sglua_move_value(maestro, L);
+                                  /* maestro: ...
+                                     L:      table key value */

 
   /* prepare the return value of __index */
   lua_pushvalue(L, -1);
 
   /* prepare the return value of __index */
   lua_pushvalue(L, -1);


@@ -552,20 +562,20 @@ static int l_get_from_father(lua_State *L) {
 }
 
 /**
 }
 
 /**

- * @brief Creates a new Lua state and get its environment from an existing state.
+ * @brief Creates a new Lua state and get its environment from the maestro
+ * state.

  *
  *

- * The state created is independent from the existing one and has its own
- * copies of global and registry values.
+ * The state created is independent from maestro and has its own copies of
+ * global and registry values.

  * However, the global and registry values are not copied right now from
  * the original state; they are copied only the first time they are accessed.
  * This behavior saves time and memory, and is okay for Simgrid's needs.
  *
  * TODO: if the simulation runs in parallel, copy everything right now?
  *
  * However, the global and registry values are not copied right now from
  * the original state; they are copied only the first time they are accessed.
  * This behavior saves time and memory, and is okay for Simgrid's needs.
  *
  * TODO: if the simulation runs in parallel, copy everything right now?
  *

- * @param father an existing state

  * @return the state created
  */
  * @return the state created
  */

-lua_State* sglua_clone_state(lua_State *father) {
+lua_State* sglua_clone_maestro(void) {

 
   /* create the new state */
   lua_State *L = luaL_newstate();
 
   /* create the new state */
   lua_State *L = luaL_newstate();


@@ -582,7 +592,7 @@ lua_State* sglua_clone_state(lua_State *father) {
   lua_newtable(L);                          /* thread newenv */
   lua_newtable(L);                          /* thread newenv mt */
   lua_pushvalue(L, LUA_REGISTRYINDEX);      /* thread newenv mt reg */
   lua_newtable(L);                          /* thread newenv */
   lua_newtable(L);                          /* thread newenv mt */
   lua_pushvalue(L, LUA_REGISTRYINDEX);      /* thread newenv mt reg */

-  lua_pushcfunction(L, l_get_from_father);  /* thread newenv mt reg f */
+  lua_pushcfunction(L, l_get_from_maestro); /* thread newenv mt reg f */

   lua_setfield(L, -3, "__index");           /* thread newenv mt reg */
   lua_pushvalue(L, -2);                     /* thread newenv mt reg mt */
   lua_setmetatable(L, -2);                  /* thread newenv mt reg */
   lua_setfield(L, -3, "__index");           /* thread newenv mt reg */
   lua_pushvalue(L, -2);                     /* thread newenv mt reg mt */
   lua_setmetatable(L, -2);                  /* thread newenv mt reg */


@@ -591,31 +601,16 @@ lua_State* sglua_clone_state(lua_State *father) {
   lua_setfenv(L, -2);                       /* thread */
   lua_pop(L, 1);                            /* -- */
 
   lua_setfenv(L, -2);                       /* thread */
   lua_pop(L, 1);                            /* -- */
 

-  /* set a pointer to the father */
-  lua_pushstring(L, "simgrid.father");      /* "simgrid.father" */
-  lua_pushlightuserdata(L, father);         /* "simgrid.father" father */
-  lua_rawset(L, LUA_REGISTRYINDEX);
-                                            /* -- */
-
-  /* create the table of visited tables from the father */
-  lua_pushstring(L, "simgrid.father_visited_tables");
-                                            /* "simgrid.father_visited_tables" */
-  lua_newtable(L);                          /* "simgrid.father_visited_tables" visited */
-  lua_rawset(L, LUA_REGISTRYINDEX);
-                                            /* -- */
-
-  /* create the table of my own visited tables */
-  lua_pushstring(L, "simgrid.visited_tables");
-                                            /* "simgrid.visited_tables" */
-  lua_newtable(L);                          /* "simgrid.visited_tables" visited */
+  /* create the table of known tables from maestro */
+  lua_pushstring(L, "simgrid.maestro_tables");
+                                            /* "simgrid.maestro_tables" */
+  lua_newtable(L);                          /* "simgrid.maestro_tables" maestrotbs*/

   lua_rawset(L, LUA_REGISTRYINDEX);
                                             /* -- */
 
   lua_rawset(L, LUA_REGISTRYINDEX);
                                             /* -- */
 

-  /* open the standard libs (theoretically, this is not necessary as they can
-   * be inherited like any global values, but without a proper support of
-   * closures, iterators like ipairs don't work). */
-  XBT_DEBUG("Metatable of globals and registry set, opening standard libraries now");
-  luaL_openlibs(L);
+  /* opening the standard libs is not necessary as they are
+   * be inherited like any global values */
+  /* luaL_openlibs(L); */

 
   XBT_DEBUG("New state created");
 
 
   XBT_DEBUG("New state created");