external/mit/lua/dist/src/lstate.c

   1 /*      $NetBSD: lstate.c,v 1.1.1.2 2012/03/15 00:08:14 alnsn Exp $     */
   2
   3 /*
   4 ** $Id: lstate.c,v 1.1.1.2 2012/03/15 00:08:14 alnsn Exp $
   5 ** Global State
   6 ** See Copyright Notice in lua.h
   7 */
   8
   9
  10 #include <stddef.h>
  11
  12 #define lstate_c
  13 #define LUA_CORE
  14
  15 #include "lua.h"
  16
  17 #include "ldebug.h"
  18 #include "ldo.h"
  19 #include "lfunc.h"
  20 #include "lgc.h"
  21 #include "llex.h"
  22 #include "lmem.h"
  23 #include "lstate.h"
  24 #include "lstring.h"
  25 #include "ltable.h"
  26 #include "ltm.h"
  27
  28
  29 #define state_size(x)   (sizeof(x) + LUAI_EXTRASPACE)
  30 #define fromstate(l)    (cast(lu_byte *, (l)) - LUAI_EXTRASPACE)
  31 #define tostate(l)   (cast(lua_State *, cast(lu_byte *, l) + LUAI_EXTRASPACE))
  32
  33
  34 /*
  35 ** Main thread combines a thread state and the global state
  36 */
  37 typedef struct LG {
  38   lua_State l;
  39   global_State g;
  40 } LG;
  41
  42
  43
  44 static void stack_init (lua_State *L1, lua_State *L) {
  45   /* initialize CallInfo array */
  46   L1->base_ci = luaM_newvector(L, BASIC_CI_SIZE, CallInfo);
  47   L1->ci = L1->base_ci;
  48   L1->size_ci = BASIC_CI_SIZE;
  49   L1->end_ci = L1->base_ci + L1->size_ci - 1;
  50   /* initialize stack array */
  51   L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, TValue);
  52   L1->stacksize = BASIC_STACK_SIZE + EXTRA_STACK;
  53   L1->top = L1->stack;
  54   L1->stack_last = L1->stack+(L1->stacksize - EXTRA_STACK)-1;
  55   /* initialize first ci */
  56   L1->ci->func = L1->top;
  57   setnilvalue(L1->top++);  /* `function' entry for this `ci' */
  58   L1->base = L1->ci->base = L1->top;
  59   L1->ci->top = L1->top + LUA_MINSTACK;
  60 }
  61
  62
  63 static void freestack (lua_State *L, lua_State *L1) {
  64   luaM_freearray(L, L1->base_ci, L1->size_ci, CallInfo);
  65   luaM_freearray(L, L1->stack, L1->stacksize, TValue);
  66 }
  67
  68
  69 /*
  70 ** open parts that may cause memory-allocation errors
  71 */
  72 static void f_luaopen (lua_State *L, void *ud) {
  73   global_State *g = G(L);
  74   UNUSED(ud);
  75   stack_init(L, L);  /* init stack */
  76   sethvalue(L, gt(L), luaH_new(L, 0, 2));  /* table of globals */
  77   sethvalue(L, registry(L), luaH_new(L, 0, 2));  /* registry */
  78   luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
  79   luaT_init(L);
  80   luaX_init(L);
  81   luaS_fix(luaS_newliteral(L, MEMERRMSG));
  82   g->GCthreshold = 4*g->totalbytes;
  83 }
  84
  85
  86 static void preinit_state (lua_State *L, global_State *g) {
  87   G(L) = g;
  88   L->stack = NULL;
  89   L->stacksize = 0;
  90   L->errorJmp = NULL;
  91   L->hook = NULL;
  92   L->hookmask = 0;
  93   L->basehookcount = 0;
  94   L->allowhook = 1;
  95   resethookcount(L);
  96   L->openupval = NULL;
  97   L->size_ci = 0;
  98   L->nCcalls = L->baseCcalls = 0;
  99   L->status = 0;
 100   L->base_ci = L->ci = NULL;
 101   L->savedpc = NULL;
 102   L->errfunc = 0;
 103   setnilvalue(gt(L));
 104 }
 105
 106
 107 static void close_state (lua_State *L) {
 108   global_State *g = G(L);
 109   luaF_close(L, L->stack);  /* close all upvalues for this thread */
 110   luaC_freeall(L);  /* collect all objects */
 111   lua_assert(g->rootgc == obj2gco(L));
 112   lua_assert(g->strt.nuse == 0);
 113   luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size, TString *);
 114   luaZ_freebuffer(L, &g->buff);
 115   freestack(L, L);
 116   lua_assert(g->totalbytes == sizeof(LG));
 117   (*g->frealloc)(g->ud, fromstate(L), state_size(LG), 0);
 118 }
 119
 120
 121 lua_State *luaE_newthread (lua_State *L) {
 122   lua_State *L1 = tostate(luaM_malloc(L, state_size(lua_State)));
 123   luaC_link(L, obj2gco(L1), LUA_TTHREAD);
 124   preinit_state(L1, G(L));
 125   stack_init(L1, L);  /* init stack */
 126   setobj2n(L, gt(L1), gt(L));  /* share table of globals */
 127   L1->hookmask = L->hookmask;
 128   L1->basehookcount = L->basehookcount;
 129   L1->hook = L->hook;
 130   resethookcount(L1);
 131   lua_assert(iswhite(obj2gco(L1)));
 132   return L1;
 133 }
 134
 135
 136 void luaE_freethread (lua_State *L, lua_State *L1) {
 137   luaF_close(L1, L1->stack);  /* close all upvalues for this thread */
 138   lua_assert(L1->openupval == NULL);
 139   luai_userstatefree(L1);
 140   freestack(L, L1);
 141   luaM_freemem(L, fromstate(L1), state_size(lua_State));
 142 }
 143
 144
 145 LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
 146   int i;
 147   lua_State *L;
 148   global_State *g;
 149   void *l = (*f)(ud, NULL, 0, state_size(LG));
 150   if (l == NULL) return NULL;
 151   L = tostate(l);
 152   g = &((LG *)L)->g;
 153   L->next = NULL;
 154   L->tt = LUA_TTHREAD;
 155   g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);
 156   L->marked = luaC_white(g);
 157   set2bits(L->marked, FIXEDBIT, SFIXEDBIT);
 158   preinit_state(L, g);
 159   g->frealloc = f;
 160   g->ud = ud;
 161   g->mainthread = L;
 162   g->uvhead.u.l.prev = &g->uvhead;
 163   g->uvhead.u.l.next = &g->uvhead;
 164   g->GCthreshold = 0;  /* mark it as unfinished state */
 165   g->strt.size = 0;
 166   g->strt.nuse = 0;
 167   g->strt.hash = NULL;
 168   setnilvalue(registry(L));
 169   luaZ_initbuffer(L, &g->buff);
 170   g->panic = NULL;
 171   g->gcstate = GCSpause;
 172   g->rootgc = obj2gco(L);
 173   g->sweepstrgc = 0;
 174   g->sweepgc = &g->rootgc;
 175   g->gray = NULL;
 176   g->grayagain = NULL;
 177   g->weak = NULL;
 178   g->tmudata = NULL;
 179   g->totalbytes = sizeof(LG);
 180   g->gcpause = LUAI_GCPAUSE;
 181   g->gcstepmul = LUAI_GCMUL;
 182   g->gcdept = 0;
 183   for (i=0; i<NUM_TAGS; i++) g->mt[i] = NULL;
 184   if (luaD_rawrunprotected(L, f_luaopen, NULL) != 0) {
 185     /* memory allocation error: free partial state */
 186     close_state(L);
 187     L = NULL;
 188   }
 189   else
 190     luai_userstateopen(L);
 191   return L;
 192 }
 193
 194
 195 static void callallgcTM (lua_State *L, void *ud) {
 196   UNUSED(ud);
 197   luaC_callGCTM(L);  /* call GC metamethods for all udata */
 198 }
 199
 200
 201 LUA_API void lua_close (lua_State *L) {
 202   L = G(L)->mainthread;  /* only the main thread can be closed */
 203   lua_lock(L);
 204   luaF_close(L, L->stack);  /* close all upvalues for this thread */
 205   luaC_separateudata(L, 1);  /* separate udata that have GC metamethods */
 206   L->errfunc = 0;  /* no error function during GC metamethods */
 207   do {  /* repeat until no more errors */
 208     L->ci = L->base_ci;
 209     L->base = L->top = L->ci->base;
 210     L->nCcalls = L->baseCcalls = 0;
 211   } while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0);
 212   lua_assert(G(L)->tmudata == NULL);
 213   luai_userstateclose(L);
 214   close_state(L);
 215 }
 216