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# lua/lstate.c

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    00001 /*
    00002 ** $Id: lstate.c,v 2.36 2006/05/24 14:15:50 roberto Exp $
    00003 ** Global State
    00004 ** See Copyright Notice in lua.h
    00005 */
    00006
    00007
    00008 #include <stddef.h>
    00009
    00010 #define lstate_c
    00011 #define LUA_CORE
    00012
    00013 #include "lua.h"
    00014
    00015 #include "ldebug.h"
    00016 #include "ldo.h"
    00017 #include "lfunc.h"
    00018 #include "lgc.h"
    00019 #include "llex.h"
    00020 #include "lmem.h"
    00021 #include "lstate.h"
    00022 #include "lstring.h"
    00023 #include "ltable.h"
    00024 #include "ltm.h"
    00025
    00026
    00027 #define state_size(x)   (sizeof(x) + LUAI_EXTRASPACE)
    00028 #define fromstate(l)    (cast(lu_byte *, (l)) - LUAI_EXTRASPACE)
    00029 #define tostate(l)   (cast(lua_State *, cast(lu_byte *, l) + LUAI_EXTRASPACE))
    00030
    00031
    00032 /*
    00033 ** Main thread combines a thread state and the global state
    00034 */
    00035 typedef struct LG {
    00036   lua_State l;
    00037   global_State g;
    00038 } LG;
    00039
    00040
    00041
    00042 static void stack_init (lua_State *L1, lua_State *L) {
    00043   /* initialize CallInfo array */
    00044   L1->base_ci = luaM_newvector(L, BASIC_CI_SIZE, CallInfo);
    00045   L1->ci = L1->base_ci;
    00046   L1->size_ci = BASIC_CI_SIZE;
    00047   L1->end_ci = L1->base_ci + L1->size_ci - 1;
    00048   /* initialize stack array */
    00049   L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, TValue);
    00050   L1->stacksize = BASIC_STACK_SIZE + EXTRA_STACK;
    00051   L1->top = L1->stack;
    00052   L1->stack_last = L1->stack+(L1->stacksize - EXTRA_STACK)-1;
    00053   /* initialize first ci */
    00054   L1->ci->func = L1->top;
    00055   setnilvalue(L1->top++);  /* `function' entry for this `ci' */
    00056   L1->base = L1->ci->base = L1->top;
    00057   L1->ci->top = L1->top + LUA_MINSTACK;
    00058 }
    00059
    00060
    00061 static void freestack (lua_State *L, lua_State *L1) {
    00062   luaM_freearray(L, L1->base_ci, L1->size_ci, CallInfo);
    00063   luaM_freearray(L, L1->stack, L1->stacksize, TValue);
    00064 }
    00065
    00066
    00067 /*
    00068 ** open parts that may cause memory-allocation errors
    00069 */
    00070 static void f_luaopen (lua_State *L, void *ud) {
    00071   global_State *g = G(L);
    00072   UNUSED(ud);
    00073   stack_init(L, L);  /* init stack */
    00074   sethvalue(L, gt(L), luaH_new(L, 0, 2));  /* table of globals */
    00075   sethvalue(L, registry(L), luaH_new(L, 0, 2));  /* registry */
    00076   luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
    00077   luaT_init(L);
    00078   luaX_init(L);
    00079   luaS_fix(luaS_newliteral(L, MEMERRMSG));
    00080   g->GCthreshold = 4*g->totalbytes;
    00081 }
    00082
    00083
    00084 static void preinit_state (lua_State *L, global_State *g) {
    00085   G(L) = g;
    00086   L->stack = NULL;
    00087   L->stacksize = 0;
    00088   L->errorJmp = NULL;
    00089   L->hook = NULL;
    00090   L->hookmask = 0;
    00091   L->basehookcount = 0;
    00092   L->allowhook = 1;
    00093   resethookcount(L);
    00094   L->openupval = NULL;
    00095   L->size_ci = 0;
    00096   L->nCcalls = 0;
    00097   L->status = 0;
    00098   L->base_ci = L->ci = NULL;
    00099   L->savedpc = NULL;
    00100   L->errfunc = 0;
    00101   setnilvalue(gt(L));
    00102 }
    00103
    00104
    00105 static void close_state (lua_State *L) {
    00106   global_State *g = G(L);
    00107   luaF_close(L, L->stack);  /* close all upvalues for this thread */
    00108   luaC_freeall(L);  /* collect all objects */
    00109   lua_assert(g->rootgc == obj2gco(L));
    00110   lua_assert(g->strt.nuse == 0);
    00111   luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size, TString *);
    00112   luaZ_freebuffer(L, &g->buff);
    00113   freestack(L, L);
    00114   lua_assert(g->totalbytes == sizeof(LG));
    00115   (*g->frealloc)(g->ud, fromstate(L), state_size(LG), 0);
    00116 }
    00117
    00118
    00119 lua_State *luaE_newthread (lua_State *L) {
    00120   lua_State *L1 = tostate(luaM_malloc(L, state_size(lua_State)));
    00121   luaC_link(L, obj2gco(L1), LUA_TTHREAD);
    00122   preinit_state(L1, G(L));
    00123   stack_init(L1, L);  /* init stack */
    00124   setobj2n(L, gt(L1), gt(L));  /* share table of globals */
    00125   L1->hookmask = L->hookmask;
    00126   L1->basehookcount = L->basehookcount;
    00127   L1->hook = L->hook;
    00128   resethookcount(L1);
    00129   lua_assert(iswhite(obj2gco(L1)));
    00130   return L1;
    00131 }
    00132
    00133
    00134 void luaE_freethread (lua_State *L, lua_State *L1) {
    00135   luaF_close(L1, L1->stack);  /* close all upvalues for this thread */
    00136   lua_assert(L1->openupval == NULL);
    00137   luai_userstatefree(L1);
    00138   freestack(L, L1);
    00139   luaM_freemem(L, fromstate(L1), state_size(lua_State));
    00140 }
    00141
    00142
    00143 LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
    00144   int i;
    00145   lua_State *L;
    00146   global_State *g;
    00147   void *l = (*f)(ud, NULL, 0, state_size(LG));
    00148   if (l == NULL) return NULL;
    00149   L = tostate(l);
    00150   g = &((LG *)L)->g;
    00151   L->next = NULL;
    00152   L->tt = LUA_TTHREAD;
    00153   g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);
    00154   L->marked = luaC_white(g);
    00155   set2bits(L->marked, FIXEDBIT, SFIXEDBIT);
    00156   preinit_state(L, g);
    00157   g->frealloc = f;
    00158   g->ud = ud;
    00159   g->mainthread = L;
    00160   g->uvhead.u.l.prev = &g->uvhead;
    00161   g->uvhead.u.l.next = &g->uvhead;
    00162   g->GCthreshold = 0;  /* mark it as unfinished state */
    00163   g->strt.size = 0;
    00164   g->strt.nuse = 0;
    00165   g->strt.hash = NULL;
    00166   setnilvalue(registry(L));
    00167   luaZ_initbuffer(L, &g->buff);
    00168   g->panic = NULL;
    00169   g->gcstate = GCSpause;
    00170   g->rootgc = obj2gco(L);
    00171   g->sweepstrgc = 0;
    00172   g->sweepgc = &g->rootgc;
    00173   g->gray = NULL;
    00174   g->grayagain = NULL;
    00175   g->weak = NULL;
    00176   g->tmudata = NULL;
    00177   g->totalbytes = sizeof(LG);
    00178   g->gcpause = LUAI_GCPAUSE;
    00179   g->gcstepmul = LUAI_GCMUL;
    00180   g->gcdept = 0;
    00181   for (i=0; i<NUM_TAGS; i++) g->mt[i] = NULL;
    00182   if (luaD_rawrunprotected(L, f_luaopen, NULL) != 0) {
    00183     /* memory allocation error: free partial state */
    00184     close_state(L);
    00185     L = NULL;
    00186   }
    00187   else
    00188     luai_userstateopen(L);
    00189   return L;
    00190 }
    00191
    00192
    00193 static void callallgcTM (lua_State *L, void *ud) {
    00194   UNUSED(ud);
    00195   luaC_callGCTM(L);  /* call GC metamethods for all udata */
    00196 }
    00197
    00198
    00199 LUA_API void lua_close (lua_State *L) {
    00200   L = G(L)->mainthread;  /* only the main thread can be closed */
    00201   lua_lock(L);
    00202   luaF_close(L, L->stack);  /* close all upvalues for this thread */
    00203   luaC_separateudata(L, 1);  /* separate udata that have GC metamethods */
    00204   L->errfunc = 0;  /* no error function during GC metamethods */
    00205   do {  /* repeat until no more errors */
    00206     L->ci = L->base_ci;
    00207     L->base = L->top = L->ci->base;
    00208     L->nCcalls = 0;
    00209   } while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0);
    00210   lua_assert(G(L)->tmudata == NULL);
    00211   luai_userstateclose(L);
    00212   close_state(L);
    00213 }
    00214