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