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 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 */ 104 void luaE_setdebt (global_State *g, l_mem debt) { 105 g->totalbytes -= (debt - g->GCdebt); 106 g->GCdebt = debt; 107 } 108 109 110 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 } 118 119 120 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 } 129 130 131 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 } 149 150 151 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 */ 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 */ 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 */ 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 } 219 220 221 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 } 233 234 235 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 } 252 253 254 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 } 262 263 264 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 } 313 314 315 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