1 /* 2 ** $Id: lstate.c,v 2.36.1.2 2008/01/03 15:20:39 roberto Exp $ 3 ** Global State 4 ** See Copyright Notice in lua.h 5 */ 6 7 8 #include <stddef.h> 9 10 #define lstate_c 11 #define LUA_CORE 12 13 #include "lua.h" 14 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 #define state_size(x) (sizeof(x) + LUAI_EXTRASPACE) 28 #define fromstate(l) (cast(lu_byte *, (l)) - LUAI_EXTRASPACE) 29 #define tostate(l) (cast(lua_State *, cast(lu_byte *, l) + LUAI_EXTRASPACE)) 30 31 32 /* 33 ** Main thread combines a thread state and the global state 34 */ 35 typedef struct LG { 36 lua_State l; 37 global_State g; 38 } LG; 39 40 41 42 static void stack_init (lua_State *L1, lua_State *L) { 43 /* initialize CallInfo array */ 44 L1->base_ci = luaM_newvector(L, BASIC_CI_SIZE, CallInfo); 45 L1->ci = L1->base_ci; 46 L1->size_ci = BASIC_CI_SIZE; 47 L1->end_ci = L1->base_ci + L1->size_ci - 1; 48 /* initialize stack array */ 49 L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, TValue); 50 L1->stacksize = BASIC_STACK_SIZE + EXTRA_STACK; 51 L1->top = L1->stack; 52 L1->stack_last = L1->stack+(L1->stacksize - EXTRA_STACK)-1; 53 /* initialize first ci */ 54 L1->ci->func = L1->top; 55 setnilvalue(L1->top++); /* `function' entry for this `ci' */ 56 L1->base = L1->ci->base = L1->top; 57 L1->ci->top = L1->top + LUA_MINSTACK; 58 } 59 60 61 static void freestack (lua_State *L, lua_State *L1) { 62 luaM_freearray(L, L1->base_ci, L1->size_ci, CallInfo); 63 luaM_freearray(L, L1->stack, L1->stacksize, TValue); 64 } 65 66 67 /* 68 ** open parts that may cause memory-allocation errors 69 */ 70 static void f_luaopen (lua_State *L, void *ud) { 71 global_State *g = G(L); 72 UNUSED(ud); 73 stack_init(L, L); /* init stack */ 74 sethvalue(L, gt(L), luaH_new(L, 0, 2)); /* table of globals */ 75 sethvalue(L, registry(L), luaH_new(L, 0, 2)); /* registry */ 76 luaS_resize(L, MINSTRTABSIZE); /* initial size of string table */ 77 luaT_init(L); 78 luaX_init(L); 79 luaS_fix(luaS_newliteral(L, MEMERRMSG)); 80 g->GCthreshold = 4*g->totalbytes; 81 } 82 83 84 static void preinit_state (lua_State *L, global_State *g) { 85 G(L) = g; 86 L->stack = NULL; 87 L->stacksize = 0; 88 L->errorJmp = NULL; 89 L->hook = NULL; 90 L->hookmask = 0; 91 L->basehookcount = 0; 92 L->allowhook = 1; 93 resethookcount(L); 94 L->openupval = NULL; 95 L->size_ci = 0; 96 L->nCcalls = L->baseCcalls = 0; 97 L->status = 0; 98 L->base_ci = L->ci = NULL; 99 L->savedpc = NULL; 100 L->errfunc = 0; 101 setnilvalue(gt(L)); 102 } 103 104 105 static void close_state (lua_State *L) { 106 global_State *g = G(L); 107 luaF_close(L, L->stack); /* close all upvalues for this thread */ 108 luaC_freeall(L); /* collect all objects */ 109 lua_assert(g->rootgc == obj2gco(L)); 110 lua_assert(g->strt.nuse == 0); 111 luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size, TString *); 112 luaZ_freebuffer(L, &g->buff); 113 freestack(L, L); 114 lua_assert(g->totalbytes == sizeof(LG)); 115 (*g->frealloc)(g->ud, fromstate(L), state_size(LG), 0); 116 } 117 118 119 lua_State *luaE_newthread (lua_State *L) { 120 lua_State *L1 = tostate(luaM_malloc(L, state_size(lua_State))); 121 luaC_link(L, obj2gco(L1), LUA_TTHREAD); 122 preinit_state(L1, G(L)); 123 stack_init(L1, L); /* init stack */ 124 setobj2n(L, gt(L1), gt(L)); /* share table of globals */ 125 L1->hookmask = L->hookmask; 126 L1->basehookcount = L->basehookcount; 127 L1->hook = L->hook; 128 resethookcount(L1); 129 lua_assert(iswhite(obj2gco(L1))); 130 return L1; 131 } 132 133 134 void luaE_freethread (lua_State *L, lua_State *L1) { 135 luaF_close(L1, L1->stack); /* close all upvalues for this thread */ 136 lua_assert(L1->openupval == NULL); 137 luai_userstatefree(L1); 138 freestack(L, L1); 139 luaM_freemem(L, fromstate(L1), state_size(lua_State)); 140 } 141 142 143 LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) { 144 int i; 145 lua_State *L; 146 global_State *g; 147 void *l = (*f)(ud, NULL, 0, state_size(LG)); 148 if (l == NULL) return NULL; 149 L = tostate(l); 150 g = &((LG *)L)->g; 151 L->next = NULL; 152 L->tt = LUA_TTHREAD; 153 g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT); 154 L->marked = luaC_white(g); 155 set2bits(L->marked, FIXEDBIT, SFIXEDBIT); 156 preinit_state(L, g); 157 g->frealloc = f; 158 g->ud = ud; 159 g->mainthread = L; 160 g->uvhead.u.l.prev = &g->uvhead; 161 g->uvhead.u.l.next = &g->uvhead; 162 g->GCthreshold = 0; /* mark it as unfinished state */ 163 g->strt.size = 0; 164 g->strt.nuse = 0; 165 g->strt.hash = NULL; 166 setnilvalue(registry(L)); 167 luaZ_initbuffer(L, &g->buff); 168 g->panic = NULL; 169 g->gcstate = GCSpause; 170 g->rootgc = obj2gco(L); 171 g->sweepstrgc = 0; 172 g->sweepgc = &g->rootgc; 173 g->gray = NULL; 174 g->grayagain = NULL; 175 g->weak = NULL; 176 g->tmudata = NULL; 177 g->totalbytes = sizeof(LG); 178 g->gcpause = LUAI_GCPAUSE; 179 g->gcstepmul = LUAI_GCMUL; 180 g->gcdept = 0; 181 for (i=0; i<NUM_TAGS; i++) g->mt[i] = NULL; 182 if (luaD_rawrunprotected(L, f_luaopen, NULL) != 0) { 183 /* memory allocation error: free partial state */ 184 close_state(L); 185 L = NULL; 186 } 187 else 188 luai_userstateopen(L); 189 return L; 190 } 191 192 193 static void callallgcTM (lua_State *L, void *ud) { 194 UNUSED(ud); 195 luaC_callGCTM(L); /* call GC metamethods for all udata */ 196 } 197 198 199 LUA_API void lua_close (lua_State *L) { 200 L = G(L)->mainthread; /* only the main thread can be closed */ 201 lua_lock(L); 202 luaF_close(L, L->stack); /* close all upvalues for this thread */ 203 luaC_separateudata(L, 1); /* separate udata that have GC metamethods */ 204 L->errfunc = 0; /* no error function during GC metamethods */ 205 do { /* repeat until no more errors */ 206 L->ci = L->base_ci; 207 L->base = L->top = L->ci->base; 208 L->nCcalls = L->baseCcalls = 0; 209 } while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0); 210 lua_assert(G(L)->tmudata == NULL); 211 luai_userstateclose(L); 212 close_state(L); 213 } 214 215