/* ** $Id: lstate.c,v 2.133.1.1 2017/04/19 17:39:34 roberto Exp $ ** Global State ** See Copyright Notice in lua.h */ #define lstate_c #define LUA_CORE #include "lprefix.h" #include #include #include "lua.h" #include "lapi.h" #include "ldebug.h" #include "ldo.h" #include "lfunc.h" #include "lgc.h" #include "llex.h" #include "lmem.h" #include "lstate.h" #include "lstring.h" #include "ltable.h" #include "ltm.h" #if !defined(LUAI_GCPAUSE) #define LUAI_GCPAUSE 200 /* 200% */ #endif #if !defined(LUAI_GCMUL) #define LUAI_GCMUL 200 /* GC runs 'twice the speed' of memory allocation */ #endif /* ** a macro to help the creation of a unique random seed when a state is ** created; the seed is used to randomize hashes. */ #if !defined(luai_makeseed) #include #define luai_makeseed() cast(unsigned int, time(NULL)) #endif /* ** thread state + extra space */ typedef struct LX { lu_byte extra_[LUA_EXTRASPACE]; lua_State l; } LX; /* ** Main thread combines a thread state and the global state */ typedef struct LG { LX l; global_State g; } LG; #define fromstate(L) (cast(LX *, cast(lu_byte *, (L)) - offsetof(LX, l))) /* ** Compute an initial seed as random as possible. Rely on Address Space ** Layout Randomization (if present) to increase randomness.. */ #define addbuff(b,p,e) \ { size_t t = cast(size_t, e); \ memcpy(b + p, &t, sizeof(t)); p += sizeof(t); } static unsigned int makeseed (lua_State *L) { char buff[4 * sizeof(size_t)]; unsigned int h = luai_makeseed(); int p = 0; addbuff(buff, p, L); /* heap variable */ addbuff(buff, p, &h); /* local variable */ addbuff(buff, p, luaO_nilobject); /* global variable */ addbuff(buff, p, &lua_newstate); /* public function */ lua_assert(p == sizeof(buff)); return luaS_hash(buff, p, h); } /* ** set GCdebt to a new value keeping the value (totalbytes + GCdebt) ** invariant (and avoiding underflows in 'totalbytes') */ void luaE_setdebt (global_State *g, l_mem debt) { l_mem tb = gettotalbytes(g); lua_assert(tb > 0); if (debt < tb - MAX_LMEM) debt = tb - MAX_LMEM; /* will make 'totalbytes == MAX_LMEM' */ g->totalbytes = tb - debt; g->GCdebt = debt; } CallInfo *luaE_extendCI (lua_State *L) { CallInfo *ci = luaM_new(L, CallInfo); lua_assert(L->ci->next == NULL); L->ci->next = ci; ci->previous = L->ci; ci->next = NULL; L->nci++; return ci; } /* ** free all CallInfo structures not in use by a thread */ void luaE_freeCI (lua_State *L) { CallInfo *ci = L->ci; CallInfo *next = ci->next; ci->next = NULL; while ((ci = next) != NULL) { next = ci->next; luaM_free(L, ci); L->nci--; } } /* ** free half of the CallInfo structures not in use by a thread */ void luaE_shrinkCI (lua_State *L) { CallInfo *ci = L->ci; CallInfo *next2; /* next's next */ /* while there are two nexts */ while (ci->next != NULL && (next2 = ci->next->next) != NULL) { luaM_free(L, ci->next); /* free next */ L->nci--; ci->next = next2; /* remove 'next' from the list */ next2->previous = ci; ci = next2; /* keep next's next */ } } static void stack_init (lua_State *L1, lua_State *L) { int i; CallInfo *ci; /* initialize stack array */ L1->stack = luaM_newvector(L, BASIC_STACK_SIZE, TValue); L1->stacksize = BASIC_STACK_SIZE; for (i = 0; i < BASIC_STACK_SIZE; i++) setnilvalue(L1->stack + i); /* erase new stack */ L1->top = L1->stack; L1->stack_last = L1->stack + L1->stacksize - EXTRA_STACK; /* initialize first ci */ ci = &L1->base_ci; ci->next = ci->previous = NULL; ci->callstatus = 0; ci->func = L1->top; setnilvalue(L1->top++); /* 'function' entry for this 'ci' */ ci->top = L1->top + LUA_MINSTACK; L1->ci = ci; } static void freestack (lua_State *L) { if (L->stack == NULL) return; /* stack not completely built yet */ L->ci = &L->base_ci; /* free the entire 'ci' list */ luaE_freeCI(L); lua_assert(L->nci == 0); luaM_freearray(L, L->stack, L->stacksize); /* free stack array */ } /* ** Create registry table and its predefined values */ static void init_registry (lua_State *L, global_State *g) { TValue temp; /* create registry */ Table *registry = luaH_new(L); sethvalue(L, &g->l_registry, registry); luaH_resize(L, registry, LUA_RIDX_LAST, 0); /* registry[LUA_RIDX_MAINTHREAD] = L */ setthvalue(L, &temp, L); /* temp = L */ luaH_setint(L, registry, LUA_RIDX_MAINTHREAD, &temp); /* registry[LUA_RIDX_GLOBALS] = table of globals */ sethvalue(L, &temp, luaH_new(L)); /* temp = new table (global table) */ luaH_setint(L, registry, LUA_RIDX_GLOBALS, &temp); } /* ** open parts of the state that may cause memory-allocation errors. ** ('g->version' != NULL flags that the state was completely build) */ static void f_luaopen (lua_State *L, void *ud) { global_State *g = G(L); UNUSED(ud); stack_init(L, L); /* init stack */ init_registry(L, g); luaS_init(L); luaT_init(L); luaX_init(L); g->gcrunning = 1; /* allow gc */ g->version = lua_version(NULL); luai_userstateopen(L); } /* ** preinitialize a thread with consistent values without allocating ** any memory (to avoid errors) */ static void preinit_thread (lua_State *L, global_State *g) { G(L) = g; L->stack = NULL; L->ci = NULL; L->nci = 0; L->stacksize = 0; L->twups = L; /* thread has no upvalues */ L->errorJmp = NULL; L->nCcalls = 0; L->hook = NULL; L->hookmask = 0; L->basehookcount = 0; L->allowhook = 1; resethookcount(L); L->openupval = NULL; L->nny = 1; L->status = LUA_OK; L->errfunc = 0; } static void close_state (lua_State *L) { global_State *g = G(L); luaF_close(L, L->stack); /* close all upvalues for this thread */ luaC_freeallobjects(L); /* collect all objects */ if (g->version) /* closing a fully built state? */ luai_userstateclose(L); luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size); freestack(L); lua_assert(gettotalbytes(g) == sizeof(LG)); (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0); /* free main block */ } LUA_API lua_State *lua_newthread (lua_State *L) { global_State *g = G(L); lua_State *L1; lua_lock(L); luaC_checkGC(L); /* create new thread */ L1 = &cast(LX *, luaM_newobject(L, LUA_TTHREAD, sizeof(LX)))->l; L1->marked = luaC_white(g); L1->tt = LUA_TTHREAD; /* link it on list 'allgc' */ L1->next = g->allgc; g->allgc = obj2gco(L1); /* anchor it on L stack */ setthvalue(L, L->top, L1); api_incr_top(L); preinit_thread(L1, g); L1->hookmask = L->hookmask; L1->basehookcount = L->basehookcount; L1->hook = L->hook; resethookcount(L1); /* initialize L1 extra space */ memcpy(lua_getextraspace(L1), lua_getextraspace(g->mainthread), LUA_EXTRASPACE); luai_userstatethread(L, L1); stack_init(L1, L); /* init stack */ lua_unlock(L); return L1; } void luaE_freethread (lua_State *L, lua_State *L1) { LX *l = fromstate(L1); luaF_close(L1, L1->stack); /* close all upvalues for this thread */ lua_assert(L1->openupval == NULL); luai_userstatefree(L, L1); freestack(L1); luaM_free(L, l); } LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) { int i; lua_State *L; global_State *g; LG *l = cast(LG *, (*f)(ud, NULL, LUA_TTHREAD, sizeof(LG))); if (l == NULL) return NULL; L = &l->l.l; g = &l->g; L->next = NULL; L->tt = LUA_TTHREAD; g->currentwhite = bitmask(WHITE0BIT); L->marked = luaC_white(g); preinit_thread(L, g); g->frealloc = f; g->ud = ud; g->mainthread = L; g->seed = makeseed(L); g->gcrunning = 0; /* no GC while building state */ g->GCestimate = 0; g->strt.size = g->strt.nuse = 0; g->strt.hash = NULL; setnilvalue(&g->l_registry); g->panic = NULL; g->version = NULL; g->gcstate = GCSpause; g->gckind = KGC_NORMAL; g->allgc = g->finobj = g->tobefnz = g->fixedgc = NULL; g->sweepgc = NULL; g->gray = g->grayagain = NULL; g->weak = g->ephemeron = g->allweak = NULL; g->twups = NULL; g->totalbytes = sizeof(LG); g->GCdebt = 0; g->gcfinnum = 0; g->gcpause = LUAI_GCPAUSE; g->gcstepmul = LUAI_GCMUL; g->gcmlock = 0; for (i=0; i < LUA_NUMTAGS; i++) g->mt[i] = NULL; if (luaD_rawrunprotected(L, f_luaopen, NULL) != LUA_OK) { /* memory allocation error: free partial state */ close_state(L); L = NULL; } return L; } LUA_API void lua_close (lua_State *L) { L = G(L)->mainthread; /* only the main thread can be closed */ lua_lock(L); close_state(L); }