commit dcc070683cf89d82aae4f2cbe00ff8dbd97392ca
parent 2d81cfa4e195a31d92d5ffff313918e4da549a71
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 10 May 2010 12:24:38 -0300
avoid reserving LUA_RIDX_LAST slots in any table used by reference
system. Store free list in a field indexed by a unique name,
instead of using a numerical index.
Diffstat:
1 file changed, 9 insertions(+), 15 deletions(-)
diff --git a/lauxlib.c b/lauxlib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lauxlib.c,v 1.207 2010/04/09 16:14:46 roberto Exp roberto $
+** $Id: lauxlib.c,v 1.208 2010/04/14 15:14:21 roberto Exp roberto $
** Auxiliary functions for building Lua libraries
** See Copyright Notice in lua.h
*/
@@ -436,8 +436,8 @@ LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {
** =======================================================
*/
-/* number of prereserved references (for internal use) */
-#define FREELIST_REF (LUA_RIDX_LAST + 1) /* free list of references */
+/* index of free-list header */
+#define freelist "lua-freelist"
LUALIB_API int luaL_ref (lua_State *L, int t) {
@@ -447,21 +447,15 @@ LUALIB_API int luaL_ref (lua_State *L, int t) {
lua_pop(L, 1); /* remove from stack */
return LUA_REFNIL; /* `nil' has a unique fixed reference */
}
- lua_rawgeti(L, t, FREELIST_REF); /* get first free element */
+ lua_getfield(L, t, freelist); /* get first free element */
ref = (int)lua_tointeger(L, -1); /* ref = t[FREELIST_REF] */
lua_pop(L, 1); /* remove it from stack */
if (ref != 0) { /* any free element? */
lua_rawgeti(L, t, ref); /* remove it from list */
- lua_rawseti(L, t, FREELIST_REF); /* (t[FREELIST_REF] = t[ref]) */
+ lua_setfield(L, t, freelist); /* (t[freelist] = t[ref]) */
}
- else { /* no free elements */
+ else /* no free elements */
ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */
- if (ref == FREELIST_REF) { /* FREELIST_REF not initialized? */
- lua_pushinteger(L, 0);
- lua_rawseti(L, t, FREELIST_REF);
- ref = FREELIST_REF + 1;
- }
- }
lua_rawseti(L, t, ref);
return ref;
}
@@ -470,10 +464,10 @@ LUALIB_API int luaL_ref (lua_State *L, int t) {
LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
if (ref >= 0) {
t = abs_index(L, t);
- lua_rawgeti(L, t, FREELIST_REF);
- lua_rawseti(L, t, ref); /* t[ref] = t[FREELIST_REF] */
+ lua_getfield(L, t, freelist);
+ lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */
lua_pushinteger(L, ref);
- lua_rawseti(L, t, FREELIST_REF); /* t[FREELIST_REF] = ref */
+ lua_setfield(L, t, freelist); /* t[freelist] = ref */
}
}