/*** $Id: lstate.c,v 2.36.1.2 2008/01/03 15:20:39 roberto Exp $** Global State** See Copyright Notice in lua.h*/#include <stddef.h>#define lstate_c#define LUA_CORE#include "lua.h"#include "ldebug.h"#include "ldo.h"#include "lfunc.h"#include "lgc.h"#include "llex.h"#include "lmem.h"#include "lstate.h"#include "lstring.h"#include "ltable.h"#include "ltm.h"#define state_size(x)	(sizeof(x) + LUAI_EXTRASPACE)#define fromstate(l)	(cast(lu_byte *, (l)) - LUAI_EXTRASPACE)#define tostate(l)   (cast(lua_State *, cast(lu_byte *, l) + LUAI_EXTRASPACE))/*** Main thread combines a thread state and the global state*/typedef struct LG {  lua_State l;  global_State g;} LG;  static void stack_init (lua_State *L1, lua_State *L) {  /* initialize CallInfo array */  L1->base_ci = luaM_newvector(L, BASIC_CI_SIZE, CallInfo);  L1->ci = L1->base_ci;  L1->size_ci = BASIC_CI_SIZE;  L1->end_ci = L1->base_ci + L1->size_ci - 1;  /* initialize stack array */  L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, TValue);  L1->stacksize = BASIC_STACK_SIZE + EXTRA_STACK;  L1->top = L1->stack;  L1->stack_last = L1->stack+(L1->stacksize - EXTRA_STACK)-1;  /* initialize first ci */  L1->ci->func = L1->top;  setnilvalue(L1->top++);  /* `function' entry for this `ci' */  L1->base = L1->ci->base = L1->top;  L1->ci->top = L1->top + LUA_MINSTACK;}static void freestack (lua_State *L, lua_State *L1) {  luaM_freearray(L, L1->base_ci, L1->size_ci, CallInfo);  luaM_freearray(L, L1->stack, L1->stacksize, TValue);}/*** open parts that may cause memory-allocation errors*/static void f_luaopen (lua_State *L, void *ud) {  global_State *g = G(L);  UNUSED(ud);  stack_init(L, L);  /* init stack */  sethvalue(L, gt(L), luaH_new(L, 0, 2));  /* table of globals */  sethvalue(L, registry(L), luaH_new(L, 0, 2));  /* registry */  luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */  luaT_init(L);  luaX_init(L);  luaS_fix(luaS_newliteral(L, MEMERRMSG));  g->GCthreshold = 4*g->totalbytes;}static void preinit_state (lua_State *L, global_State *g) {  G(L) = g;  L->stack = NULL;  L->stacksize = 0;  L->errorJmp = NULL;  L->hook = NULL;  L->hookmask = 0;  L->basehookcount = 0;  L->allowhook = 1;  resethookcount(L);  L->openupval = NULL;  L->size_ci = 0;  L->nCcalls = L->baseCcalls = 0;  L->status = 0;  L->base_ci = L->ci = NULL;  L->savedpc = NULL;  L->errfunc = 0;  setnilvalue(gt(L));}static void close_state (lua_State *L) {  global_State *g = G(L);  luaF_close(L, L->stack);  /* close all upvalues for this thread */  luaC_freeall(L);  /* collect all objects */  lua_assert(g->rootgc == obj2gco(L));  lua_assert(g->strt.nuse == 0);  luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size, TString *);  luaZ_freebuffer(L, &g->buff);  freestack(L, L);  lua_assert(g->totalbytes == sizeof(LG));  (*g->frealloc)(g->ud, fromstate(L), state_size(LG), 0);}lua_State *luaE_newthread (lua_State *L) {  lua_State *L1 = tostate(luaM_malloc(L, state_size(lua_State)));  luaC_link(L, obj2gco(L1), LUA_TTHREAD);  preinit_state(L1, G(L));  stack_init(L1, L);  /* init stack */  setobj2n(L, gt(L1), gt(L));  /* share table of globals */  L1->hookmask = L->hookmask;  L1->basehookcount = L->basehookcount;  L1->hook = L->hook;  resethookcount(L1);  lua_assert(iswhite(obj2gco(L1)));  return L1;}void luaE_freethread (lua_State *L, lua_State *L1) {  luaF_close(L1, L1->stack);  /* close all upvalues for this thread */  lua_assert(L1->openupval == NULL);  luai_userstatefree(L1);  freestack(L, L1);  luaM_freemem(L, fromstate(L1), state_size(lua_State));}LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {  int i;  lua_State *L;  global_State *g;  void *l = (*f)(ud, NULL, 0, state_size(LG));  if (l == NULL) return NULL;  L = tostate(l);  g = &((LG *)L)->g;  L->next = NULL;  L->tt = LUA_TTHREAD;  g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);  L->marked = luaC_white(g);  set2bits(L->marked, FIXEDBIT, SFIXEDBIT);  preinit_state(L, g);  g->frealloc = f;  g->ud = ud;  g->mainthread = L;  g->uvhead.u.l.prev = &g->uvhead;  g->uvhead.u.l.next = &g->uvhead;  g->GCthreshold = 0;  /* mark it as unfinished state */  g->strt.size = 0;  g->strt.nuse = 0;  g->strt.hash = NULL;  setnilvalue(registry(L));  luaZ_initbuffer(L, &g->buff);  g->panic = NULL;  g->gcstate = GCSpause;  g->rootgc = obj2gco(L);  g->sweepstrgc = 0;  g->sweepgc = &g->rootgc;  g->gray = NULL;  g->grayagain = NULL;  g->weak = NULL;  g->tmudata = NULL;  g->totalbytes = sizeof(LG);  g->gcpause = LUAI_GCPAUSE;  g->gcstepmul = LUAI_GCMUL;  g->gcdept = 0;  for (i=0; i<NUM_TAGS; i++) g->mt[i] = NULL;  if (luaD_rawrunprotected(L, f_luaopen, NULL) != 0) {    /* memory allocation error: free partial state */    close_state(L);    L = NULL;  }  else    luai_userstateopen(L);  return L;}static void callallgcTM (lua_State *L, void *ud) {  UNUSED(ud);  luaC_callGCTM(L);  /* call GC metamethods for all udata */}LUA_API void lua_close (lua_State *L) {  L = G(L)->mainthread;  /* only the main thread can be closed */  lua_lock(L);  luaF_close(L, L->stack);  /* close all upvalues for this thread */  luaC_separateudata(L, 1);  /* separate udata that have GC metamethods */  L->errfunc = 0;  /* no error function during GC metamethods */  do {  /* repeat until no more errors */    L->ci = L->base_ci;    L->base = L->top = L->ci->base;    L->nCcalls = L->baseCcalls = 0;  } while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0);  lua_assert(G(L)->tmudata == NULL);  luai_userstateclose(L);  close_state(L);}