1/*
2** $Id: lstate.c,v 2.99.1.2 2013/11/08 17:45:31 roberto Exp $
3** Global State
4** See Copyright Notice in lua.h
5*/
6
7
8#include <sys/zfs_context.h>
9
10#define lstate_c
11#define LUA_CORE
12
13#include "lua.h"
14
15#include "lapi.h"
16#include "ldebug.h"
17#include "ldo.h"
18#include "lfunc.h"
19#include "lgc.h"
20#include "llex.h"
21#include "lmem.h"
22#include "lstate.h"
23#include "lstring.h"
24#include "ltable.h"
25#include "ltm.h"
26
27
28#if !defined(LUAI_GCPAUSE)
29#define LUAI_GCPAUSE	200  /* 200% */
30#endif
31
32#if !defined(LUAI_GCMAJOR)
33#define LUAI_GCMAJOR	200  /* 200% */
34#endif
35
36#if !defined(LUAI_GCMUL)
37#define LUAI_GCMUL	200 /* GC runs 'twice the speed' of memory allocation */
38#endif
39
40
41#define MEMERRMSG	"not enough memory"
42
43
44/*
45** a macro to help the creation of a unique random seed when a state is
46** created; the seed is used to randomize hashes.
47*/
48#if !defined(luai_makeseed)
49#define luai_makeseed()		cast(unsigned int, gethrtime())
50#endif
51
52
53
54/*
55** thread state + extra space
56*/
57typedef struct LX {
58#if defined(LUAI_EXTRASPACE)
59  char buff[LUAI_EXTRASPACE];
60#endif
61  lua_State l;
62} LX;
63
64
65/*
66** Main thread combines a thread state and the global state
67*/
68typedef struct LG {
69  LX l;
70  global_State g;
71} LG;
72
73
74
75#define fromstate(L)	(cast(LX *, cast(lu_byte *, (L)) - offsetof(LX, l)))
76
77
78/*
79** Compute an initial seed as random as possible. In ANSI, rely on
80** Address Space Layout Randomization (if present) to increase
81** randomness..
82*/
83#define addbuff(b,p,e) \
84  { size_t t = cast(size_t, e); \
85    memcpy(buff + p, &t, sizeof(t)); p += sizeof(t); }
86
87static unsigned int makeseed (lua_State *L) {
88  char buff[4 * sizeof(size_t)];
89  unsigned int h = luai_makeseed();
90  int p = 0;
91  addbuff(buff, p, L);  /* heap variable */
92  addbuff(buff, p, &h);  /* local variable */
93  addbuff(buff, p, luaO_nilobject);  /* global variable */
94  addbuff(buff, p, &lua_newstate);  /* public function */
95  lua_assert(p == sizeof(buff));
96  return luaS_hash(buff, p, h);
97}
98
99
100/*
101** set GCdebt to a new value keeping the value (totalbytes + GCdebt)
102** invariant
103*/
104void luaE_setdebt (global_State *g, l_mem debt) {
105  g->totalbytes -= (debt - g->GCdebt);
106  g->GCdebt = debt;
107}
108
109
110CallInfo *luaE_extendCI (lua_State *L) {
111  CallInfo *ci = luaM_new(L, CallInfo);
112  lua_assert(L->ci->next == NULL);
113  L->ci->next = ci;
114  ci->previous = L->ci;
115  ci->next = NULL;
116  return ci;
117}
118
119
120void luaE_freeCI (lua_State *L) {
121  CallInfo *ci = L->ci;
122  CallInfo *next = ci->next;
123  ci->next = NULL;
124  while ((ci = next) != NULL) {
125    next = ci->next;
126    luaM_free(L, ci);
127  }
128}
129
130
131static void stack_init (lua_State *L1, lua_State *L) {
132  int i; CallInfo *ci;
133  /* initialize stack array */
134  L1->stack = luaM_newvector(L, BASIC_STACK_SIZE, TValue);
135  L1->stacksize = BASIC_STACK_SIZE;
136  for (i = 0; i < BASIC_STACK_SIZE; i++)
137    setnilvalue(L1->stack + i);  /* erase new stack */
138  L1->top = L1->stack;
139  L1->stack_last = L1->stack + L1->stacksize - EXTRA_STACK;
140  /* initialize first ci */
141  ci = &L1->base_ci;
142  ci->next = ci->previous = NULL;
143  ci->callstatus = 0;
144  ci->func = L1->top;
145  setnilvalue(L1->top++);  /* 'function' entry for this 'ci' */
146  ci->top = L1->top + LUA_MINSTACK;
147  L1->ci = ci;
148}
149
150
151static void freestack (lua_State *L) {
152  if (L->stack == NULL)
153    return;  /* stack not completely built yet */
154  L->ci = &L->base_ci;  /* free the entire 'ci' list */
155  luaE_freeCI(L);
156  luaM_freearray(L, L->stack, L->stacksize);  /* free stack array */
157}
158
159
160/*
161** Create registry table and its predefined values
162*/
163static void init_registry (lua_State *L, global_State *g) {
164  TValue mt;
165  /* create registry */
166  Table *registry = luaH_new(L);
167  sethvalue(L, &g->l_registry, registry);
168  luaH_resize(L, registry, LUA_RIDX_LAST, 0);
169  /* registry[LUA_RIDX_MAINTHREAD] = L */
170  setthvalue(L, &mt, L);
171  luaH_setint(L, registry, LUA_RIDX_MAINTHREAD, &mt);
172  /* registry[LUA_RIDX_GLOBALS] = table of globals */
173  sethvalue(L, &mt, luaH_new(L));
174  luaH_setint(L, registry, LUA_RIDX_GLOBALS, &mt);
175}
176
177
178/*
179** open parts of the state that may cause memory-allocation errors
180*/
181static void f_luaopen (lua_State *L, void *ud) {
182  global_State *g = G(L);
183  UNUSED(ud);
184  stack_init(L, L);  /* init stack */
185  init_registry(L, g);
186  luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
187  luaT_init(L);
188  luaX_init(L);
189  /* pre-create memory-error message */
190  g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
191  luaS_fix(g->memerrmsg);  /* it should never be collected */
192  g->gcrunning = 1;  /* allow gc */
193  g->version = lua_version(NULL);
194  luai_userstateopen(L);
195}
196
197
198/*
199** preinitialize a state with consistent values without allocating
200** any memory (to avoid errors)
201*/
202static void preinit_state (lua_State *L, global_State *g) {
203  G(L) = g;
204  L->stack = NULL;
205  L->ci = NULL;
206  L->stacksize = 0;
207  L->errorJmp = NULL;
208  L->nCcalls = 0;
209  L->hook = NULL;
210  L->hookmask = 0;
211  L->basehookcount = 0;
212  L->allowhook = 1;
213  resethookcount(L);
214  L->openupval = NULL;
215  L->nny = 1;
216  L->status = LUA_OK;
217  L->errfunc = 0;
218}
219
220
221static 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);
229  freestack(L);
230  lua_assert(gettotalbytes(g) == sizeof(LG));
231  (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0);  /* free main block */
232}
233
234
235LUA_API lua_State *lua_newthread (lua_State *L) {
236  lua_State *L1;
237  lua_lock(L);
238  luaC_checkGC(L);
239  L1 = &luaC_newobj(L, LUA_TTHREAD, sizeof(LX), NULL, offsetof(LX, l))->th;
240  setthvalue(L, L->top, L1);
241  api_incr_top(L);
242  preinit_state(L1, G(L));
243  L1->hookmask = L->hookmask;
244  L1->basehookcount = L->basehookcount;
245  L1->hook = L->hook;
246  resethookcount(L1);
247  luai_userstatethread(L, L1);
248  stack_init(L1, L);  /* init stack */
249  lua_unlock(L);
250  return L1;
251}
252
253
254void 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);
259  freestack(L1);
260  luaM_free(L, l);
261}
262
263
264LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
265  int i;
266  lua_State *L;
267  global_State *g;
268  LG *l = cast(LG *, (*f)(ud, NULL, LUA_TTHREAD, sizeof(LG)));
269  if (l == NULL) return NULL;
270  L = &l->l.l;
271  g = &l->g;
272  L->next = NULL;
273  L->tt = LUA_TTHREAD;
274  g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);
275  L->marked = luaC_white(g);
276  g->gckind = KGC_NORMAL;
277  preinit_state(L, g);
278  g->frealloc = f;
279  g->ud = ud;
280  g->mainthread = L;
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 */
285  g->GCestimate = 0;
286  g->strt.size = 0;
287  g->strt.nuse = 0;
288  g->strt.hash = NULL;
289  setnilvalue(&g->l_registry);
290  luaZ_initbuffer(L, &g->buff);
291  g->panic = NULL;
292  g->version = NULL;
293  g->gcstate = GCSpause;
294  g->allgc = NULL;
295  g->finobj = NULL;
296  g->tobefnz = NULL;
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);
301  g->GCdebt = 0;
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 */
308    close_state(L);
309    L = NULL;
310  }
311  return L;
312}
313
314
315LUA_API void lua_close (lua_State *L) {
316  L = G(L)->mainthread;  /* only the main thread can be closed */
317  lua_lock(L);
318  close_state(L);
319}
320
321
322