1 /* Copyright (c) 2010-2014. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
7 /* SimGrid Lua state management */
9 #include "lua_state_cloner.h"
10 #include "lua_utils.h"
16 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(lua_state_cloner, bindings, "Lua state management");
18 static void sglua_add_maestro_table(lua_State* L, int index, void* maestro_table_ptr);
19 static void sglua_remove_maestro_table(lua_State* L, int index, void* maestro_table_ptr);
20 static void* sglua_get_maestro_table_ptr(lua_State* L, int index);
21 static void sglua_get_table_by_ptr(lua_State* L, void* table_ptr);
22 static int l_get_from_maestro(lua_State* L);
24 static void sglua_copy_nil(lua_State* src, lua_State* dst);
25 static void sglua_copy_number(lua_State* src, lua_State* dst);
26 static void sglua_copy_boolean(lua_State* src, lua_State* dst);
27 static void sglua_copy_string(lua_State* src, lua_State* dst);
28 static void sglua_copy_table(lua_State* src, lua_State* dst);
29 static void sglua_copy_function(lua_State* src, lua_State* dst);
30 static void sglua_copy_lightuserdata(lua_State* src, lua_State* dst);
31 static void sglua_copy_userdata(lua_State* src, lua_State* dst);
32 static void sglua_copy_thread(lua_State* src, lua_State* dst);
35 * @brief Adds a reference to a maestro table to the list of known maestro
38 * TODO identify maestro's tables with my own IDs instead of pointers
41 * @param L a state (can be maestro itself)
42 * @param index index of the copy of the maestro table in the stack of L
43 * @param maestro_table_ptr pointer to the original table in maestro's world
45 static void sglua_add_maestro_table(lua_State* L, int index, void* maestro_table_ptr) {
47 /* we will set both [ptr] -> table and [table] -> ptr */
50 lua_pushvalue(L, index);
52 lua_pushstring(L, "simgrid.maestro_tables");
53 /* ... table "simgrid.maestro_tables" */
54 lua_rawget(L, LUA_REGISTRYINDEX);
55 /* ... table maestrotbs */
57 /* ... table maestrotbs table */
58 lua_pushlightuserdata(L, maestro_table_ptr);
59 /* ... table maestrotbs table tableptr */
61 /* ... table maestrotbs table tableptr tableptr */
63 /* ... table maestrotbs table tableptr tableptr table */
65 /* ... table maestrotbs table tableptr */
67 /* ... table maestrotbs */
73 * @brief Removes a reference to a maestro table to the list of known maestro
76 * @param L a state (can be maestro itself)
77 * @param index index of the copy of the maestro table in the stack of L
78 * @param maestro_table_ptr pointer to the original table in maestro's world
80 static void sglua_remove_maestro_table(lua_State* L, int index, void* maestro_table_ptr) {
82 /* we will unset both [ptr] -> table and [table] -> ptr */
85 lua_pushvalue(L, index);
87 lua_pushstring(L, "simgrid.maestro_tables");
88 /* ... table "simgrid.maestro_tables" */
89 lua_rawget(L, LUA_REGISTRYINDEX);
90 /* ... table maestrotbs */
92 /* ... table maestrotbs table */
94 /* ... table maestrotbs table nil */
95 lua_pushlightuserdata(L, maestro_table_ptr);
96 /* ... table maestrotbs table nil tableptr */
98 /* ... table maestrotbs table nil tableptr nil*/
100 /* ... table maestrotbs table nil */
102 /* ... table maestrotbs */
108 * @brief For a table in the stack of L, returns a pointer that identifies the
109 * same table in in maestro's world.
110 * @param L a Lua state
111 * @param index index of a table in the stack of L
112 * @return a pointer to maestro's copy of this table, or NULL if this table
113 * did not come from maestro
115 static void* sglua_get_maestro_table_ptr(lua_State* L, int index) {
117 void* maestro_table_ptr = NULL;
119 lua_pushvalue(L, index);
121 lua_pushstring(L, "simgrid.maestro_tables");
122 /* ... table "simgrid.maestro_tables" */
123 lua_rawget(L, LUA_REGISTRYINDEX);
124 /* ... table maestrotbs */
125 lua_pushvalue(L, -2);
126 /* ... table maestrotbs table */
128 /* ... table maestrotbs tableptr/nil */
129 if (!lua_isnil(L, -1)) {
130 /* ... table maestrotbs tableptr */
131 maestro_table_ptr = (void*) lua_topointer(L, -1);
136 return maestro_table_ptr;
140 * @brief Pushes a table knowing a pointer to maestro's copy of this table.
142 * Pushes nil if L does not know this table in maestro.
144 * @param L a Lua state
145 * @param maestro_table_ptr pointer that identifies a table in maestro's world
147 static void sglua_get_table_by_ptr(lua_State* L, void* maestro_table_ptr) {
150 lua_pushstring(L, "simgrid.maestro_tables");
151 /* ... "simgrid.maestro_tables" */
152 lua_rawget(L, LUA_REGISTRYINDEX);
154 lua_pushlightuserdata(L, maestro_table_ptr);
155 /* ... maestrotbs tableptr */
157 /* ... maestrotbs table/nil */
163 * @brief Pops a value from the stack of a source state and pushes it on the
164 * stack of another state.
165 * If the value is a table, its content is copied recursively.
167 * This function is similar to lua_xmove() but it allows to move a value
168 * between two different global states.
170 * @param src the source state (not necessarily maestro)
171 * @param dst the destination state
173 void sglua_move_value(lua_State* src, lua_State* dst) {
175 sglua_copy_value(src, dst);
180 * @brief Pushes onto the stack a copy of the value on top another stack.
181 * If the value is a table, its content is copied recursively.
183 * This function allows to move a value between two different global states.
185 * @param src the source state (not necessarily maestro)
186 * @param dst the destination state
188 void sglua_copy_value(lua_State* src, lua_State* dst) {
190 luaL_checkany(src, -1); /* check the value to copy */
192 int indent = (lua_gettop(dst) - 1) * 6;
193 XBT_DEBUG("%sCopying data %s", sglua_get_spaces(indent), sglua_tostring(src, -1));
195 sglua_stack_dump("src before copying a value (should be ... value): ", src);
196 sglua_stack_dump("dst before copying a value (should be ...): ", dst);
198 switch (lua_type(src, -1)) {
201 sglua_copy_nil(src, dst);
205 sglua_copy_number(src, dst);
209 sglua_copy_boolean(src, dst);
213 sglua_copy_string(src, dst);
217 sglua_copy_function(src, dst);
221 sglua_copy_table(src, dst);
224 case LUA_TLIGHTUSERDATA:
225 sglua_copy_lightuserdata(src, dst);
229 sglua_copy_userdata(src, dst);
233 sglua_copy_thread(src, dst);
237 XBT_ERROR("This index is acceptable but non-valid");
241 XBT_DEBUG("%sData copied", sglua_get_spaces(indent));
243 sglua_stack_dump("src after copying a value (should be ... value): ", src);
244 sglua_stack_dump("dst after copying a value (should be ... value): ", dst);
248 * @brief Copies the nil value on the top of src to the top of dst.
249 * @param src source state
250 * @param dst destination state
252 static void sglua_copy_nil(lua_State* src, lua_State* dst) {
257 * @brief Copies the number value on the top of src to the top of dst.
258 * @param src source state
259 * @param dst destination state
261 static void sglua_copy_number(lua_State* src, lua_State* dst) {
262 lua_pushnumber(dst, lua_tonumber(src, -1));
266 * @brief Copies the boolean value on the top of src to the top of dst.
267 * @param src source state
268 * @param dst destination state
270 static void sglua_copy_boolean(lua_State* src, lua_State* dst) {
271 lua_pushboolean(dst, lua_toboolean(src, -1));
275 * @brief Copies the string value on the top of src to the top of dst.
276 * @param src source state
277 * @param dst destination state
279 static void sglua_copy_string(lua_State* src, lua_State* dst) {
281 /* no worries about memory: lua_pushstring makes a copy */
282 lua_pushstring(dst, lua_tostring(src, -1));
286 * @brief Copies the table value on top of src to the top of dst.
288 * A deep copy of the table is made. If the table has a metatable, the
289 * metatable is also copied.
290 * If the table comes from maestro and is already known by the destination
291 * state, it is not copied again.
293 * @param src source state
294 * @param dst destination state
296 static void sglua_copy_table(lua_State* src, lua_State* dst) {
300 int indent = lua_gettop(dst) * 6 + 2;
302 /* get from maestro the pointer that identifies this table */
303 void* table_ptr = sglua_get_maestro_table_ptr(src, -1);
304 int known_by_maestro = (table_ptr != NULL);
306 if (!known_by_maestro) {
307 /* the table didn't come from maestro: nevermind, use the pointer of src */
308 table_ptr = (void*) lua_topointer(src, -1);
309 XBT_DEBUG("%sMaestro does not know this table",
310 sglua_get_spaces(indent));
313 if (sglua_is_maestro(src)) {
314 /* register the table in maestro itself */
315 XBT_DEBUG("%sKeeping track of this table in maestro itself",
316 sglua_get_spaces(indent));
317 sglua_add_maestro_table(src, -1, table_ptr);
318 known_by_maestro = 1;
319 xbt_assert(sglua_get_maestro_table_ptr(src, -1) == table_ptr);
322 /* to avoid infinite recursion, see if this table is already known by dst */
323 sglua_get_table_by_ptr(dst, table_ptr);
324 /* dst: ... table/nil */
325 if (!lua_isnil(dst, -1)) {
326 XBT_DEBUG("%sNothing to do: table already known (%p)",
327 sglua_get_spaces(indent), table_ptr);
331 XBT_DEBUG("%sFirst visit of this table (%p)", sglua_get_spaces(indent),
337 /* first visit: create the new table in dst */
341 /* mark the table as known right now to avoid infinite recursion */
342 sglua_add_maestro_table(dst, -1, table_ptr);
343 /* we may have added a table with a non-maestro pointer, but if it was the
344 * case, we will remove it later */
345 XBT_DEBUG("%sTable marked as known", sglua_get_spaces(indent));
346 xbt_assert(sglua_get_maestro_table_ptr(dst, -1) == table_ptr);
348 sglua_stack_dump("dst after marking the table as known (should be ... table): ", dst);
350 /* copy the metatable if any */
351 int has_meta_table = lua_getmetatable(src, -1);
352 /* src: ... table mt? */
353 if (has_meta_table) {
354 XBT_DEBUG("%sCopying the metatable", sglua_get_spaces(indent));
355 /* src: ... table mt */
356 sglua_copy_table(src, dst);
357 /* dst: ... table mt */
360 lua_setmetatable(dst, -2);
365 XBT_DEBUG("%sNo metatable", sglua_get_spaces(indent));
368 sglua_stack_dump("src before traversing the table (should be ... table): ", src);
369 sglua_stack_dump("dst before traversing the table (should be ... table): ", dst);
371 /* traverse the table of src and copy each element */
373 /* src: ... table nil */
374 while (lua_next(src, -2) != 0) {
375 /* src: ... table key value */
377 XBT_DEBUG("%sCopying table element %s", sglua_get_spaces(indent),
378 sglua_keyvalue_tostring(src, -2, -1));
380 sglua_stack_dump("src before copying table element (should be ... table key value): ", src);
381 sglua_stack_dump("dst before copying table element (should be ... table): ", dst);
384 lua_pushvalue(src, -2);
385 /* src: ... table key value key */
387 XBT_DEBUG("%sCopying the key part of the table element",
388 sglua_get_spaces(indent));
389 sglua_move_value(src, dst);
390 /* src: ... table key value
391 dst: ... table key */
392 XBT_DEBUG("%sCopied the key part of the table element",
393 sglua_get_spaces(indent));
396 XBT_DEBUG("%sCopying the value part of the table element",
397 sglua_get_spaces(indent));
398 sglua_move_value(src, dst);
399 /* src: ... table key
400 dst: ... table key value */
401 XBT_DEBUG("%sCopied the value part of the table element",
402 sglua_get_spaces(indent));
405 /* set the table element */
406 lua_settable(dst, -3);
409 /* the key stays on top of src for next iteration */
410 sglua_stack_dump("src before next iteration (should be ... table key): ", src);
411 sglua_stack_dump("dst before next iteration (should be ... table): ", dst);
413 XBT_DEBUG("%sTable element copied", sglua_get_spaces(indent));
415 XBT_DEBUG("%sFinished traversing the table", sglua_get_spaces(indent));
418 if (!known_by_maestro) {
419 /* actually,it was not a maestro table: forget the pointer */
420 sglua_remove_maestro_table(dst, -1, table_ptr);
425 * @brief Copies the function on the top of src to the top of dst.
427 * It can be a Lua function or a C function.
429 * @param src source state
430 * @param dst destination state
432 static void sglua_copy_function(lua_State* src, lua_State* dst) {
434 if (lua_iscfunction(src, -1)) {
435 /* it's a C function */
437 XBT_DEBUG("It's a C function");
438 sglua_stack_dump("src before copying upvalues: ", src);
440 /* get the function pointer */
441 int function_index = lua_gettop(src);
442 lua_CFunction f = lua_tocfunction(src, function_index);
444 /* copy the upvalues */
446 const char* upvalue_name = NULL;
449 upvalue_name = lua_getupvalue(src, function_index, i);
451 if (upvalue_name != NULL) {
452 XBT_DEBUG("Upvalue %s", upvalue_name);
453 sglua_move_value(src, dst);
455 } while (upvalue_name != NULL);
457 sglua_stack_dump("src before copying pointer: ", src);
459 /* set the function */
460 lua_pushcclosure(dst, f, i - 1);
461 XBT_DEBUG("Function pointer copied");
464 /* it's a Lua function: dump it from src */
466 s_sglua_buffer_t buffer;
467 buffer.capacity = 128; /* an empty function uses 77 bytes */
469 buffer.data = xbt_new(char, buffer.capacity);
471 /* copy the binary chunk from src into a buffer
472 * c.heinrich: Added parameter TRUE for Lua 5.3 - this strips all debug
473 * information from the function.
475 // Was before merge: XBT_GNUC_UNUSED and was replaced with XBT_ATTRIB_UNUSED
476 XBT_ATTRIB_UNUSED int error = lua_dump(src, sglua_memory_writer, &buffer, TRUE);
477 xbt_assert(!error, "Failed to dump the function from the source state: error %d",
479 XBT_DEBUG("Fonction dumped: %zu bytes", buffer.size);
482 fwrite(buffer.data, buffer.size, buffer.size, stderr);
483 fprintf(stderr, "\n");
486 /* load the chunk into dst */
487 error = luaL_loadbuffer(dst, buffer.data, buffer.size, "(dumped function)");
488 xbt_assert(!error, "Failed to load the function into the destination state: %s",
489 lua_tostring(dst, -1));
494 * @brief Copies the light userdata on the top of src to the top of dst.
495 * @param src source state
496 * @param dst destination state
498 static void sglua_copy_lightuserdata(lua_State* src, lua_State* dst) {
499 lua_pushlightuserdata(dst, lua_touserdata(src, -1));
503 * @brief Copies the full userdata on the top of src to the top of dst.
505 * If the userdata has a metatable, the metatable is also copied.
507 * @param src source state
508 * @param dst destination state
510 static void sglua_copy_userdata(lua_State* src, lua_State* dst) {
512 int indent = lua_gettop(dst) * 6 + 2;
517 size_t size = lua_rawlen(src, -1);
518 void* src_block = lua_touserdata(src, -1);
519 void* dst_block = lua_newuserdata(dst, size);
521 memcpy(dst_block, src_block, size);
523 /* copy the metatable if any */
524 int has_meta_table = lua_getmetatable(src, -1);
525 /* src: ... udata mt? */
526 if (has_meta_table) {
527 XBT_DEBUG("%sCopying metatable of userdata (%p)",
528 sglua_get_spaces(indent), lua_topointer(src, -1));
529 /* src: ... udata mt */
530 sglua_copy_table(src, dst);
535 lua_setmetatable(dst, -2);
538 XBT_DEBUG("%sMetatable of userdata copied", sglua_get_spaces(indent));
541 XBT_DEBUG("%sNo metatable for this userdata",
542 sglua_get_spaces(indent));
548 * @brief This operation is not supported (yet?) so it just pushes nil.
550 * @param src source state
551 * @param dst destination state
553 static void sglua_copy_thread(lua_State* src, lua_State* dst) {
555 XBT_WARN("Copying a thread from another state is not implemented (yet?).");
560 * @brief Copies a global value or a registry value from the maestro state.
562 * The state L must have been created by sglua_clone_maestro_state().
563 * This function is meant to be an __index metamethod.
564 * Consequently, it assumes that the stack has two elements:
565 * a table (either the environment or the registry of L) and the string key of
566 * a value that does not exist yet in this table. It copies the corresponding
567 * value from maestro and pushes it on the stack of L.
568 * If the value does not exist in maestro state either, nil is pushed.
570 * TODO: make this function thread safe. If the simulation runs in parallel,
571 * several simulated processes may trigger this __index metamethod at the same
572 * time and get globals from maestro.
574 * @param L the current state
575 * @return number of return values pushed (always 1)
577 static int l_get_from_maestro(lua_State *L) {
579 /* check the arguments */
580 luaL_checktype(L, 1, LUA_TTABLE);
581 const char* key = luaL_checkstring(L, 2);
583 XBT_DEBUG("__index of '%s' begins", key);
585 /* want a global or a registry value? */
587 if (lua_compare(L, 1, LUA_REGISTRYINDEX, LUA_OPEQ)) {
589 pseudo_index = LUA_REGISTRYINDEX;
590 XBT_DEBUG("Will get the value from the registry of maestro");
594 pseudo_index = lua_getfield(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS);
595 XBT_DEBUG("Will get the value from the globals of maestro");
599 lua_State* maestro = sglua_get_maestro();
603 /* get the value from maestro */
604 lua_getfield(maestro, pseudo_index, key);
605 /* maestro: ... value */
607 /* push the value onto the stack of L */
608 sglua_move_value(maestro, L);
610 L: table key value */
612 /* prepare the return value of __index */
613 lua_pushvalue(L, -1);
614 /* L: table key value value */
616 /* L: value table key value */
618 /* save the copied value in the table for subsequent accesses */
624 XBT_DEBUG("__index of '%s' returns %s", key, sglua_tostring(L, -1));
630 * @brief Creates a new Lua state and get its environment from the maestro
633 * The state created is independent from maestro and has its own copies of
634 * global and registry values.
635 * However, the global and registry values are not copied right now from
636 * the original state; they are copied only the first time they are accessed.
637 * This behavior saves time and memory, and is okay for Simgrid's needs.
639 * TODO: if the simulation runs in parallel, copy everything right now?
641 * @return the state created
643 lua_State* sglua_clone_maestro(void) {
645 /* create the new state */
646 lua_State *L = luaL_newstate();
648 /* set its environment and its registry:
649 * - create a table newenv
650 * - create a metatable mt
651 * - set mt.__index = a function that copies the global from the father state
652 * - set mt as the metatable of the registry
653 * - set mt as the metatable of newenv
654 * - set newenv as the environment of the new state
656 lua_pushthread(L); /* thread */
657 lua_newtable(L); /* thread newenv */
658 lua_newtable(L); /* thread newenv mt */
659 lua_pushvalue(L, LUA_REGISTRYINDEX); /* thread newenv mt reg */
660 lua_pushcfunction(L, l_get_from_maestro); /* thread newenv mt reg f */
661 lua_setfield(L, -3, "__index"); /* thread newenv mt reg */
662 lua_pushvalue(L, -2); /* thread newenv mt reg mt */
663 lua_setmetatable(L, -2); /* thread newenv mt reg */
664 lua_pop(L, 1); /* thread newenv mt */
665 lua_setmetatable(L, -2); /* thread newenv */
666 // TODO c.heinrich This needs to be re-implemented
667 /*lua_setfenv(L, -2); [> thread <]*/
668 lua_pop(L, 1); /* -- */
670 /* create the table of known tables from maestro */
671 lua_pushstring(L, "simgrid.maestro_tables");
672 /* "simgrid.maestro_tables" */
673 lua_newtable(L); /* "simgrid.maestro_tables" maestrotbs */
674 lua_rawset(L, LUA_REGISTRYINDEX);
677 /* opening the standard libs is not necessary as they are
678 * inherited like any global values */
679 /* luaL_openlibs(L); */
681 XBT_DEBUG("New state created");