luaC_fullgc
luaC_fullgc(L, 0);
luaC_fullgc(L, 0); /* perform a full regular collection */
LUAI_FUNC void luaC_fullgc (lua_State *L, int isemergency);
((void)(!(G(L)->gcrunning) || (luaC_fullgc(L, 0), 1)))
luaC_fullgc(L, 1); /* force a GC whenever possible */
luaC_fullgc(L, 1); /* try to free some memory... */