- XBT_DEBUG("Copying value %s", name);
-
- stack_dump("src before copying a value (should be ... value): ", src);
- stack_dump("dst before copying a value (should be visited ...): ", dst);
-
- switch (lua_type(src, -1)) {
-
- case LUA_TNIL:
- lua_pushnil(dst);
- break;
-
- case LUA_TNUMBER:
- lua_pushnumber(dst, lua_tonumber(src, -1));
- break;
-
- case LUA_TBOOLEAN:
- lua_pushboolean(dst, lua_toboolean(src, -1));
- break;
-
- case LUA_TSTRING:
- /* no worries about memory: lua_pushstring makes a copy */
- lua_pushstring(dst, lua_tostring(src, -1));
- break;
-
- case LUA_TFUNCTION:
- /* it's a function that does not exist yet in L2 */
-
- if (lua_iscfunction(src, -1)) {
- /* it's a C function: just copy the pointer */
- XBT_DEBUG("Copying C function '%s'", name);
- lua_CFunction f = lua_tocfunction(src, -1);
- lua_pushcfunction(dst, f);
- }
- else {
- /* it's a Lua function: dump it from src */
- XBT_DEBUG("Dumping Lua function '%s'", name);
-
- s_buffer_t buffer;
- buffer.capacity = 64;
- buffer.size = 0;
- buffer.data = xbt_new(char, buffer.capacity);
-
- /* copy the binary chunk from src into a buffer */
- int error = lua_dump(src, writer, &buffer);
- xbt_assert(!error, "Failed to dump function '%s' from the source state: error %d",
- name, error);
-
- /* load the chunk into dst */
- error = luaL_loadbuffer(dst, buffer.data, buffer.size, name);
- xbt_assert(!error, "Failed to load function '%s' from the source state: %s",
- name, lua_tostring(dst, -1));
- XBT_DEBUG("Function '%s' successfully dumped from source state.", name);
- }
- break;
-
- case LUA_TTABLE:
-
- /* see if this table was already visited */
- 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("Nothing to do: table already visited");
- /* dst: visited ... table */
- }
- else {
- XBT_DEBUG("First visit of this table");
- /* dst: visited ... nil */
- lua_pop(dst, 1);
- /* dst: visited ... */
-
- /* first visit: create the new table in dst */
- lua_newtable(dst);
- /* dst: visited ... table */
-
- /* mark the table as visited 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_settable(dst, 1);
- /* dst: visited ... table */
- XBT_DEBUG("Table marked as visited");
-
- stack_dump("dst after marking the table as visited (should be visited ... table): ", dst);
-
- /* copy the metatable if any */
- int has_meta_table = lua_getmetatable(src, -1);
- /* src: ... table mt? */
- if (has_meta_table) {
- XBT_DEBUG("Copying metatable");
- /* src: ... table mt */
- move_value(dst, src, "metatable");
- /* src: ... table
- dst: visited ... table mt */
- lua_setmetatable(dst, -2);
- /* dst: visited ... table */
- }
- else {
- XBT_DEBUG("No metatable");
- }
-
- stack_dump("src before traversing the table (should be ... table): ", src);
- stack_dump("dst before traversing the table (should be visited ... table): ", dst);
-
- /* traverse the table of src and copy each element */
- lua_pushnil(src);
- /* src: ... table nil */
- while (lua_next(src, -2) != 0) {
- /* src: ... table key value */
-
- XBT_DEBUG("Copying table element %s", keyvalue_tostring(src, -2, -1));
-
- stack_dump("src before copying table element (should be ... table key value): ", src);
- stack_dump("dst before copying table element (should be visited ... table): ", dst);
-
- /* copy the key */
- lua_pushvalue(src, -2);
- /* src: ... table key value key */
- XBT_DEBUG("Copying the element key");
- move_value(dst, src, value_tostring(src, -1));
- /* src: ... table key value
- dst: visited ... table key */
- XBT_DEBUG("Copied the element key");
-
- /* copy the value */
- XBT_DEBUG("Copying the element value");
- move_value(dst, src, value_tostring(src, -1));
- /* src: ... table key
- dst: visited ... table key value */
- XBT_DEBUG("Copied the element value");
-
- /* set the table element */
- lua_settable(dst, -3);
- /* dst: visited ... table */
-
- /* the key stays on top of src for next iteration */
- stack_dump("src before next iteration (should be ... table key): ", src);
- stack_dump("dst before next iteration (should be visited ... table): ", dst);
- }
- XBT_DEBUG("Finished traversing the table");
- }
- break;
-
- case LUA_TLIGHTUSERDATA:
- lua_pushlightuserdata(dst, lua_touserdata(src, -1));
- break;
-
- case LUA_TUSERDATA:
- XBT_WARN("Cannot copy a full userdata from the source state.");
- lua_pushnil(dst);
- break;
-
- case LUA_TTHREAD:
- XBT_WARN("Cannot copy a thread from the source state.");
- lua_pushnil(dst);
- break;
- }
-
- /* pop the value from src */
- lua_pop(src, 1);
-
- stack_dump("src after copying a value (should be ...): ", src);
- stack_dump("dst after copying a value (should be visited ... value): ", dst);
-}
-
-/**
- * @brief Copies a global value from the father state.
- *
- * The state L must have a father, i.e. it should have been created by
- * clone_lua_state().
- * This function is meant to be an __index metamethod.
- * Consequently, it assumes that the stack has two elements:
- * a table (usually the environment of L) and the string key of a value
- * that does not exist yet in this table. It copies the corresponding global
- * value from the father state and pushes it on the stack of L.
- * If the global value does not exist in the father 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
- * time and get globals from maestro.
- *
- * @param L the current state
- * @return number of return values pushed (always 1)
- */
-static int l_get_from_father(lua_State *L) {
-
- /* retrieve the father */
- lua_getfield(L, LUA_REGISTRYINDEX, "simgrid.father_state");
- lua_State* father = lua_touserdata(L, -1);
- xbt_assert(father != NULL, "This Lua state has no father");
- lua_pop(L, 1);
-
- /* get the global from the father */
- const char* key = luaL_checkstring(L, 2); /* L: table key */
- lua_getglobal(father, key); /* father: ... value */
- XBT_DEBUG("__index of '%s' begins", key);
-
- /* push the value onto the stack of L */
- lua_newtable(L); /* L: table key visited */
- lua_insert(L, 1); /* L: visited table key */
- move_value(L, father, key); /* father: ...
- L: visited table key value */
- lua_remove(L, 1); /* L: table key value */
-
- /* prepare the return value of __index */
- lua_pushvalue(L, -1); /* L: table key value value */
- lua_insert(L, 1); /* L: value table key value */
-
- /* save the copied value in the table for subsequent accesses */
- lua_settable(L, -3); /* L: value table */
- lua_remove(L, 2); /* L: value */
-
- XBT_DEBUG("__index of '%s' returns %s", key, value_tostring(L, -1));
-
- return 1;