3 ** $Id: lstate.c,v 2.99.1.2 2013/11/08 17:45:31 roberto Exp $
5 ** See Copyright Notice in lua.h
12 #include <sys/lua/lua.h>
27 #if !defined(LUAI_GCPAUSE)
28 #define LUAI_GCPAUSE 200 /* 200% */
31 #if !defined(LUAI_GCMAJOR)
32 #define LUAI_GCMAJOR 200 /* 200% */
35 #if !defined(LUAI_GCMUL)
36 #define LUAI_GCMUL 200 /* GC runs 'twice the speed' of memory allocation */
40 #define MEMERRMSG "not enough memory"
44 ** a macro to help the creation of a unique random seed when a state is
45 ** created; the seed is used to randomize hashes.
47 #if !defined(luai_makeseed)
48 #define luai_makeseed() cast(unsigned int, gethrtime())
54 ** thread state + extra space
57 #if defined(LUAI_EXTRASPACE)
58 char buff[LUAI_EXTRASPACE];
65 ** Main thread combines a thread state and the global state
74 #define fromstate(L) (cast(LX *, cast(lu_byte *, (L)) - offsetof(LX, l)))
78 ** Compute an initial seed as random as possible. In ANSI, rely on
79 ** Address Space Layout Randomization (if present) to increase
82 #define addbuff(b,p,e) \
83 { size_t t = cast(size_t, e); \
84 memcpy(buff + p, &t, sizeof(t)); p += sizeof(t); }
86 static unsigned int makeseed (lua_State *L) {
87 char buff[4 * sizeof(size_t)];
88 unsigned int h = luai_makeseed();
90 addbuff(buff, p, L); /* heap variable */
91 addbuff(buff, p, &h); /* local variable */
92 addbuff(buff, p, luaO_nilobject); /* global variable */
93 addbuff(buff, p, &lua_newstate); /* public function */
94 lua_assert(p == sizeof(buff));
95 return luaS_hash(buff, p, h);
100 ** set GCdebt to a new value keeping the value (totalbytes + GCdebt)
103 void luaE_setdebt (global_State *g, l_mem debt) {
104 g->totalbytes -= (debt - g->GCdebt);
109 CallInfo *luaE_extendCI (lua_State *L) {
110 CallInfo *ci = luaM_new(L, CallInfo);
111 lua_assert(L->ci->next == NULL);
113 ci->previous = L->ci;
119 void luaE_freeCI (lua_State *L) {
120 CallInfo *ci = L->ci;
121 CallInfo *next = ci->next;
123 while ((ci = next) != NULL) {
130 static void stack_init (lua_State *L1, lua_State *L) {
132 /* initialize stack array */
133 L1->stack = luaM_newvector(L, BASIC_STACK_SIZE, TValue);
134 L1->stacksize = BASIC_STACK_SIZE;
135 for (i = 0; i < BASIC_STACK_SIZE; i++)
136 setnilvalue(L1->stack + i); /* erase new stack */
138 L1->stack_last = L1->stack + L1->stacksize - EXTRA_STACK;
139 /* initialize first ci */
141 ci->next = ci->previous = NULL;
144 setnilvalue(L1->top++); /* 'function' entry for this 'ci' */
145 ci->top = L1->top + LUA_MINSTACK;
150 static void freestack (lua_State *L) {
151 if (L->stack == NULL)
152 return; /* stack not completely built yet */
153 L->ci = &L->base_ci; /* free the entire 'ci' list */
155 luaM_freearray(L, L->stack, L->stacksize); /* free stack array */
160 ** Create registry table and its predefined values
162 static void init_registry (lua_State *L, global_State *g) {
164 /* create registry */
165 Table *registry = luaH_new(L);
166 sethvalue(L, &g->l_registry, registry);
167 luaH_resize(L, registry, LUA_RIDX_LAST, 0);
168 /* registry[LUA_RIDX_MAINTHREAD] = L */
169 setthvalue(L, &mt, L);
170 luaH_setint(L, registry, LUA_RIDX_MAINTHREAD, &mt);
171 /* registry[LUA_RIDX_GLOBALS] = table of globals */
172 sethvalue(L, &mt, luaH_new(L));
173 luaH_setint(L, registry, LUA_RIDX_GLOBALS, &mt);
178 ** open parts of the state that may cause memory-allocation errors
180 static void f_luaopen (lua_State *L, void *ud) {
181 global_State *g = G(L);
183 stack_init(L, L); /* init stack */
185 luaS_resize(L, MINSTRTABSIZE); /* initial size of string table */
188 /* pre-create memory-error message */
189 g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
190 luaS_fix(g->memerrmsg); /* it should never be collected */
191 g->gcrunning = 1; /* allow gc */
192 g->version = lua_version(NULL);
193 luai_userstateopen(L);
198 ** preinitialize a state with consistent values without allocating
199 ** any memory (to avoid errors)
201 static void preinit_state (lua_State *L, global_State *g) {
210 L->basehookcount = 0;
221 static void close_state (lua_State *L) {
222 global_State *g = G(L);
223 luaF_close(L, L->stack); /* close all upvalues for this thread */
224 luaC_freeallobjects(L); /* collect all objects */
225 if (g->version) /* closing a fully built state? */
226 luai_userstateclose(L);
227 luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size);
228 luaZ_freebuffer(L, &g->buff);
230 lua_assert(gettotalbytes(g) == sizeof(LG));
231 (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0); /* free main block */
235 LUA_API lua_State *lua_newthread (lua_State *L) {
239 L1 = &luaC_newobj(L, LUA_TTHREAD, sizeof(LX), NULL, offsetof(LX, l))->th;
240 setthvalue(L, L->top, L1);
242 preinit_state(L1, G(L));
243 L1->hookmask = L->hookmask;
244 L1->basehookcount = L->basehookcount;
247 luai_userstatethread(L, L1);
248 stack_init(L1, L); /* init stack */
254 void luaE_freethread (lua_State *L, lua_State *L1) {
255 LX *l = fromstate(L1);
256 luaF_close(L1, L1->stack); /* close all upvalues for this thread */
257 lua_assert(L1->openupval == NULL);
258 luai_userstatefree(L, L1);
264 LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
268 LG *l = cast(LG *, (*f)(ud, NULL, LUA_TTHREAD, sizeof(LG)));
269 if (l == NULL) return NULL;
274 g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);
275 L->marked = luaC_white(g);
276 g->gckind = KGC_NORMAL;
281 g->seed = makeseed(L);
282 g->uvhead.u.l.prev = &g->uvhead;
283 g->uvhead.u.l.next = &g->uvhead;
284 g->gcrunning = 0; /* no GC while building state */
289 setnilvalue(&g->l_registry);
290 luaZ_initbuffer(L, &g->buff);
293 g->gcstate = GCSpause;
297 g->sweepgc = g->sweepfin = NULL;
298 g->gray = g->grayagain = NULL;
299 g->weak = g->ephemeron = g->allweak = NULL;
300 g->totalbytes = sizeof(LG);
302 g->gcpause = LUAI_GCPAUSE;
303 g->gcmajorinc = LUAI_GCMAJOR;
304 g->gcstepmul = LUAI_GCMUL;
305 for (i=0; i < LUA_NUMTAGS; i++) g->mt[i] = NULL;
306 if (luaD_rawrunprotected(L, f_luaopen, NULL) != LUA_OK) {
307 /* memory allocation error: free partial state */
315 LUA_API void lua_close (lua_State *L) {
316 L = G(L)->mainthread; /* only the main thread can be closed */