1 /* BEGIN CSTYLED */ 2 /* 3 ** $Id: lstate.c,v 2.99.1.2 2013/11/08 17:45:31 roberto Exp $ 4 ** Global State 5 ** See Copyright Notice in lua.h 6 */ 7 8 9 #define lstate_c 10 #define LUA_CORE 11 12 #include <sys/lua/lua.h> 13 14 #include "lapi.h" 15 #include "ldebug.h" 16 #include "ldo.h" 17 #include "lfunc.h" 18 #include "lgc.h" 19 #include "llex.h" 20 #include "lmem.h" 21 #include "lstate.h" 22 #include "lstring.h" 23 #include "ltable.h" 24 #include "ltm.h" 25 26 27 #if !defined(LUAI_GCPAUSE) 28 #define LUAI_GCPAUSE 200 /* 200% */ 29 #endif 30 31 #if !defined(LUAI_GCMAJOR) 32 #define LUAI_GCMAJOR 200 /* 200% */ 33 #endif 34 35 #if !defined(LUAI_GCMUL) 36 #define LUAI_GCMUL 200 /* GC runs 'twice the speed' of memory allocation */ 37 #endif 38 39 40 #define MEMERRMSG "not enough memory" 41 42 43 /* 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. 46 */ 47 #if !defined(luai_makeseed) 48 #define luai_makeseed() cast(unsigned int, gethrtime()) 49 #endif 50 51 52 53 /* 54 ** thread state + extra space 55 */ 56 typedef struct LX { 57 #if defined(LUAI_EXTRASPACE) 58 char buff[LUAI_EXTRASPACE]; 59 #endif 60 lua_State l; 61 } LX; 62 63 64 /* 65 ** Main thread combines a thread state and the global state 66 */ 67 typedef struct LG { 68 LX l; 69 global_State g; 70 } LG; 71 72 73 74 #define fromstate(L) (cast(LX *, cast(lu_byte *, (L)) - offsetof(LX, l))) 75 76 77 /* 78 ** Compute an initial seed as random as possible. In ANSI, rely on 79 ** Address Space Layout Randomization (if present) to increase 80 ** randomness.. 81 */ 82 #define addbuff(b,p,e) \ 83 { size_t t = cast(size_t, e); \ 84 memcpy(buff + p, &t, sizeof(t)); p += sizeof(t); } 85 86 static unsigned int makeseed (lua_State *L) { 87 char buff[4 * sizeof(size_t)]; 88 unsigned int h = luai_makeseed(); 89 int p = 0; 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); 96 } 97 98 99 /* 100 ** set GCdebt to a new value keeping the value (totalbytes + GCdebt) 101 ** invariant 102 */ 103 void luaE_setdebt (global_State *g, l_mem debt) { 104 g->totalbytes -= (debt - g->GCdebt); 105 g->GCdebt = debt; 106 } 107 108 109 CallInfo *luaE_extendCI (lua_State *L) { 110 CallInfo *ci = luaM_new(L, CallInfo); 111 lua_assert(L->ci->next == NULL); 112 L->ci->next = ci; 113 ci->previous = L->ci; 114 ci->next = NULL; 115 return ci; 116 } 117 118 119 void luaE_freeCI (lua_State *L) { 120 CallInfo *ci = L->ci; 121 CallInfo *next = ci->next; 122 ci->next = NULL; 123 while ((ci = next) != NULL) { 124 next = ci->next; 125 luaM_free(L, ci); 126 } 127 } 128 129 130 static void stack_init (lua_State *L1, lua_State *L) { 131 int i; CallInfo *ci; 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 */ 137 L1->top = L1->stack; 138 L1->stack_last = L1->stack + L1->stacksize - EXTRA_STACK; 139 /* initialize first ci */ 140 ci = &L1->base_ci; 141 ci->next = ci->previous = NULL; 142 ci->callstatus = 0; 143 ci->func = L1->top; 144 setnilvalue(L1->top++); /* 'function' entry for this 'ci' */ 145 ci->top = L1->top + LUA_MINSTACK; 146 L1->ci = ci; 147 } 148 149 150 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 */ 154 luaE_freeCI(L); 155 luaM_freearray(L, L->stack, L->stacksize); /* free stack array */ 156 } 157 158 159 /* 160 ** Create registry table and its predefined values 161 */ 162 static void init_registry (lua_State *L, global_State *g) { 163 TValue mt; 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); 174 } 175 176 177 /* 178 ** open parts of the state that may cause memory-allocation errors 179 */ 180 static void f_luaopen (lua_State *L, void *ud) { 181 global_State *g = G(L); 182 UNUSED(ud); 183 stack_init(L, L); /* init stack */ 184 init_registry(L, g); 185 luaS_resize(L, MINSTRTABSIZE); /* initial size of string table */ 186 luaT_init(L); 187 luaX_init(L); 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); 194 } 195 196 197 /* 198 ** preinitialize a state with consistent values without allocating 199 ** any memory (to avoid errors) 200 */ 201 static void preinit_state (lua_State *L, global_State *g) { 202 G(L) = g; 203 L->stack = NULL; 204 L->ci = NULL; 205 L->stacksize = 0; 206 L->errorJmp = NULL; 207 L->nCcalls = 0; 208 L->hook = NULL; 209 L->hookmask = 0; 210 L->basehookcount = 0; 211 L->allowhook = 1; 212 resethookcount(L); 213 L->openupval = NULL; 214 L->nny = 1; 215 L->status = LUA_OK; 216 L->errfunc = 0; 217 L->runerror = 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 /* END CSTYLED */ 321