Lua 5.1.4: lstate.c

L0001    /*
L0002    ** $Id: lstate.c,v 2.36.1.2 2008/01/03 15:20:39 roberto Exp $
L0003    ** Global State
L0004    ** See Copyright Notice in lua.h
L0005    */
L0006    
L0007    
L0008    #include <stddef.h>
L0009    
L0010    #define lstate_c
L0011    #define LUA_CORE
L0012    
L0013    #include "lua.h"
L0014    
L0015    #include "ldebug.h"
L0016    #include "ldo.h"
L0017    #include "lfunc.h"
L0018    #include "lgc.h"
L0019    #include "llex.h"
L0020    #include "lmem.h"
L0021    #include "lstate.h"
L0022    #include "lstring.h"
L0023    #include "ltable.h"
L0024    #include "ltm.h"
L0025    
L0026    
L0027    #define state_size(x)	(sizeof(x) + LUAI_EXTRASPACE)
L0028    #define fromstate(l)	(cast(lu_byte *, (l)) - LUAI_EXTRASPACE)
L0029    #define tostate(l)   (cast(lua_State *, cast(lu_byte *, l) + LUAI_EXTRASPACE))
L0030    
L0031    
L0032    /*
L0033    ** Main thread combines a thread state and the global state
L0034    */
L0035    typedef struct LG {
L0036      lua_State l;
L0037      global_State g;
L0038    } LG;
L0039      
L0040    
L0041    
L0042    static void stack_init (lua_State *L1, lua_State *L) {
L0043      /* initialize CallInfo array */
L0044      L1->base_ci = luaM_newvector(L, BASIC_CI_SIZE, CallInfo);
L0045      L1->ci = L1->base_ci;
L0046      L1->size_ci = BASIC_CI_SIZE;
L0047      L1->end_ci = L1->base_ci + L1->size_ci - 1;
L0048      /* initialize stack array */
L0049      L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, TValue);
L0050      L1->stacksize = BASIC_STACK_SIZE + EXTRA_STACK;
L0051      L1->top = L1->stack;
L0052      L1->stack_last = L1->stack+(L1->stacksize - EXTRA_STACK)-1;
L0053      /* initialize first ci */
L0054      L1->ci->func = L1->top;
L0055      setnilvalue(L1->top++);  /* `function' entry for this `ci' */
L0056      L1->base = L1->ci->base = L1->top;
L0057      L1->ci->top = L1->top + LUA_MINSTACK;
L0058    }
L0059    
L0060    
L0061    static void freestack (lua_State *L, lua_State *L1) {
L0062      luaM_freearray(L, L1->base_ci, L1->size_ci, CallInfo);
L0063      luaM_freearray(L, L1->stack, L1->stacksize, TValue);
L0064    }
L0065    
L0066    
L0067    /*
L0068    ** open parts that may cause memory-allocation errors
L0069    */
L0070    static void f_luaopen (lua_State *L, void *ud) {
L0071      global_State *g = G(L);
L0072      UNUSED(ud);
L0073      stack_init(L, L);  /* init stack */
L0074      sethvalue(L, gt(L), luaH_new(L, 0, 2));  /* table of globals */
L0075      sethvalue(L, registry(L), luaH_new(L, 0, 2));  /* registry */
L0076      luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
L0077      luaT_init(L);
L0078      luaX_init(L);
L0079      luaS_fix(luaS_newliteral(L, MEMERRMSG));
L0080      g->GCthreshold = 4*g->totalbytes;
L0081    }
L0082    
L0083    
L0084    static void preinit_state (lua_State *L, global_State *g) {
L0085      G(L) = g;
L0086      L->stack = NULL;
L0087      L->stacksize = 0;
L0088      L->errorJmp = NULL;
L0089      L->hook = NULL;
L0090      L->hookmask = 0;
L0091      L->basehookcount = 0;
L0092      L->allowhook = 1;
L0093      resethookcount(L);
L0094      L->openupval = NULL;
L0095      L->size_ci = 0;
L0096      L->nCcalls = L->baseCcalls = 0;
L0097      L->status = 0;
L0098      L->base_ci = L->ci = NULL;
L0099      L->savedpc = NULL;
L0100      L->errfunc = 0;
L0101      setnilvalue(gt(L));
L0102    }
L0103    
L0104    
L0105    static void close_state (lua_State *L) {
L0106      global_State *g = G(L);
L0107      luaF_close(L, L->stack);  /* close all upvalues for this thread */
L0108      luaC_freeall(L);  /* collect all objects */
L0109      lua_assert(g->rootgc == obj2gco(L));
L0110      lua_assert(g->strt.nuse == 0);
L0111      luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size, TString *);
L0112      luaZ_freebuffer(L, &g->buff);
L0113      freestack(L, L);
L0114      lua_assert(g->totalbytes == sizeof(LG));
L0115      (*g->frealloc)(g->ud, fromstate(L), state_size(LG), 0);
L0116    }
L0117    
L0118    
L0119    lua_State *luaE_newthread (lua_State *L) {
L0120      lua_State *L1 = tostate(luaM_malloc(L, state_size(lua_State)));
L0121      luaC_link(L, obj2gco(L1), LUA_TTHREAD);
L0122      preinit_state(L1, G(L));
L0123      stack_init(L1, L);  /* init stack */
L0124      setobj2n(L, gt(L1), gt(L));  /* share table of globals */
L0125      L1->hookmask = L->hookmask;
L0126      L1->basehookcount = L->basehookcount;
L0127      L1->hook = L->hook;
L0128      resethookcount(L1);
L0129      lua_assert(iswhite(obj2gco(L1)));
L0130      return L1;
L0131    }
L0132    
L0133    
L0134    void luaE_freethread (lua_State *L, lua_State *L1) {
L0135      luaF_close(L1, L1->stack);  /* close all upvalues for this thread */
L0136      lua_assert(L1->openupval == NULL);
L0137      luai_userstatefree(L1);
L0138      freestack(L, L1);
L0139      luaM_freemem(L, fromstate(L1), state_size(lua_State));
L0140    }
L0141    
L0142    
L0143    LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
L0144      int i;
L0145      lua_State *L;
L0146      global_State *g;
L0147      void *l = (*f)(ud, NULL, 0, state_size(LG));
L0148      if (l == NULL) return NULL;
L0149      L = tostate(l);
L0150      g = &((LG *)L)->g;
L0151      L->next = NULL;
L0152      L->tt = LUA_TTHREAD;
L0153      g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);
L0154      L->marked = luaC_white(g);
L0155      set2bits(L->marked, FIXEDBIT, SFIXEDBIT);
L0156      preinit_state(L, g);
L0157      g->frealloc = f;
L0158      g->ud = ud;
L0159      g->mainthread = L;
L0160      g->uvhead.u.l.prev = &g->uvhead;
L0161      g->uvhead.u.l.next = &g->uvhead;
L0162      g->GCthreshold = 0;  /* mark it as unfinished state */
L0163      g->strt.size = 0;
L0164      g->strt.nuse = 0;
L0165      g->strt.hash = NULL;
L0166      setnilvalue(registry(L));
L0167      luaZ_initbuffer(L, &g->buff);
L0168      g->panic = NULL;
L0169      g->gcstate = GCSpause;
L0170      g->rootgc = obj2gco(L);
L0171      g->sweepstrgc = 0;
L0172      g->sweepgc = &g->rootgc;
L0173      g->gray = NULL;
L0174      g->grayagain = NULL;
L0175      g->weak = NULL;
L0176      g->tmudata = NULL;
L0177      g->totalbytes = sizeof(LG);
L0178      g->gcpause = LUAI_GCPAUSE;
L0179      g->gcstepmul = LUAI_GCMUL;
L0180      g->gcdept = 0;
L0181      for (i=0; i<NUM_TAGS; i++) g->mt[i] = NULL;
L0182      if (luaD_rawrunprotected(L, f_luaopen, NULL) != 0) {
L0183        /* memory allocation error: free partial state */
L0184        close_state(L);
L0185        L = NULL;
L0186      }
L0187      else
L0188        luai_userstateopen(L);
L0189      return L;
L0190    }
L0191    
L0192    
L0193    static void callallgcTM (lua_State *L, void *ud) {
L0194      UNUSED(ud);
L0195      luaC_callGCTM(L);  /* call GC metamethods for all udata */
L0196    }
L0197    
L0198    
L0199    LUA_API void lua_close (lua_State *L) {
L0200      L = G(L)->mainthread;  /* only the main thread can be closed */
L0201      lua_lock(L);
L0202      luaF_close(L, L->stack);  /* close all upvalues for this thread */
L0203      luaC_separateudata(L, 1);  /* separate udata that have GC metamethods */
L0204      L->errfunc = 0;  /* no error function during GC metamethods */
L0205      do {  /* repeat until no more errors */
L0206        L->ci = L->base_ci;
L0207        L->base = L->top = L->ci->base;
L0208        L->nCcalls = L->baseCcalls = 0;
L0209      } while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0);
L0210      lua_assert(G(L)->tmudata == NULL);
L0211      luai_userstateclose(L);
L0212      close_state(L);
L0213    }
L0214