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 */
57 typedef 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 */
68 typedef 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
makeseed(lua_State * L)87 static 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 */
luaE_setdebt(global_State * g,l_mem debt)104 void luaE_setdebt (global_State *g, l_mem debt) {
105 g->totalbytes -= (debt - g->GCdebt);
106 g->GCdebt = debt;
107 }
108
109
luaE_extendCI(lua_State * L)110 CallInfo *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
luaE_freeCI(lua_State * L)120 void 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
stack_init(lua_State * L1,lua_State * L)131 static 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
freestack(lua_State * L)151 static 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 */
init_registry(lua_State * L,global_State * g)163 static 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 */
f_luaopen(lua_State * L,void * ud)181 static 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 */
preinit_state(lua_State * L,global_State * g)202 static 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
close_state(lua_State * L)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);
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
lua_newthread(lua_State * L)235 LUA_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
luaE_freethread(lua_State * L,lua_State * L1)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);
259 freestack(L1);
260 luaM_free(L, l);
261 }
262
263
lua_newstate(lua_Alloc f,void * ud)264 LUA_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
lua_close(lua_State * L)315 LUA_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