lib-src/lua/lstate.h

   1 /*
   2 ** $Id: lstate.h,v 2.24.1.2 2008/01/03 15:20:39 roberto Exp $
   3 ** Global State
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7 #ifndef lstate_h
   8 #define lstate_h
   9
  10 #include "lua.h"
  11
  12 #include "lobject.h"
  13 #include "ltm.h"
  14 #include "lzio.h"
  15
  16
  17
  18 struct lua_longjmp;  /* defined in ldo.c */
  19
  20
  21 /* table of globals */
  22 #define gt(L)   (&L->l_gt)
  23
  24 /* registry */
  25 #define registry(L)     (&G(L)->l_registry)
  26
  27
  28 /* extra stack space to handle TM calls and some other extras */
  29 #define EXTRA_STACK   5
  30
  31
  32 #define BASIC_CI_SIZE           8
  33
  34 #define BASIC_STACK_SIZE        (2*LUA_MINSTACK)
  35
  36
  37
  38 typedef struct stringtable {
  39   GCObject **hash;
  40   lu_int32 nuse;  /* number of elements */
  41   int size;
  42 } stringtable;
  43
  44
  45 /*
  46 ** informations about a call
  47 */
  48 typedef struct CallInfo {
  49   StkId base;  /* base for this function */
  50   StkId func;  /* function index in the stack */
  51   StkId top;  /* top for this function */
  52   const Instruction *savedpc;
  53   int nresults;  /* expected number of results from this function */
  54   int tailcalls;  /* number of tail calls lost under this entry */
  55 } CallInfo;
  56
  57
  58
  59 #define curr_func(L)    (clvalue(L->ci->func))
  60 #define ci_func(ci)     (clvalue((ci)->func))
  61 #define f_isLua(ci)     (!ci_func(ci)->c.isC)
  62 #define isLua(ci)       (ttisfunction((ci)->func) && f_isLua(ci))
  63
  64
  65 /*
  66 ** `global state', shared by all threads of this state
  67 */
  68 typedef struct global_State {
  69   stringtable strt;  /* hash table for strings */
  70   lua_Alloc frealloc;  /* function to reallocate memory */
  71   void *ud;         /* auxiliary data to `frealloc' */
  72   lu_byte currentwhite;
  73   lu_byte gcstate;  /* state of garbage collector */
  74   int sweepstrgc;  /* position of sweep in `strt' */
  75   GCObject *rootgc;  /* list of all collectable objects */
  76   GCObject **sweepgc;  /* position of sweep in `rootgc' */
  77   GCObject *gray;  /* list of gray objects */
  78   GCObject *grayagain;  /* list of objects to be traversed atomically */
  79   GCObject *weak;  /* list of weak tables (to be cleared) */
  80   GCObject *tmudata;  /* last element of list of userdata to be GC */
  81   Mbuffer buff;  /* temporary buffer for string concatentation */
  82   lu_mem GCthreshold;
  83   lu_mem totalbytes;  /* number of bytes currently allocated */
  84   lu_mem estimate;  /* an estimate of number of bytes actually in use */
  85   lu_mem gcdept;  /* how much GC is `behind schedule' */
  86   int gcpause;  /* size of pause between successive GCs */
  87   int gcstepmul;  /* GC `granularity' */
  88   lua_CFunction panic;  /* to be called in unprotected errors */
  89   TValue l_registry;
  90   struct lua_State *mainthread;
  91   UpVal uvhead;  /* head of double-linked list of all open upvalues */
  92   struct Table *mt[NUM_TAGS];  /* metatables for basic types */
  93   TString *tmname[TM_N];  /* array with tag-method names */
  94 } global_State;
  95
  96
  97 /*
  98 ** `per thread' state
  99 */
 100 struct lua_State {
 101   CommonHeader;
 102   lu_byte status;
 103   StkId top;  /* first free slot in the stack */
 104   StkId base;  /* base of current function */
 105   global_State *l_G;
 106   CallInfo *ci;  /* call info for current function */
 107   const Instruction *savedpc;  /* `savedpc' of current function */
 108   StkId stack_last;  /* last free slot in the stack */
 109   StkId stack;  /* stack base */
 110   CallInfo *end_ci;  /* points after end of ci array*/
 111   CallInfo *base_ci;  /* array of CallInfo's */
 112   int stacksize;
 113   int size_ci;  /* size of array `base_ci' */
 114   unsigned short nCcalls;  /* number of nested C calls */
 115   unsigned short baseCcalls;  /* nested C calls when resuming coroutine */
 116   lu_byte hookmask;
 117   lu_byte allowhook;
 118   int basehookcount;
 119   int hookcount;
 120   lua_Hook hook;
 121   TValue l_gt;  /* table of globals */
 122   TValue env;  /* temporary place for environments */
 123   GCObject *openupval;  /* list of open upvalues in this stack */
 124   GCObject *gclist;
 125   struct lua_longjmp *errorJmp;  /* current error recover point */
 126   ptrdiff_t errfunc;  /* current error handling function (stack index) */
 127 };
 128
 129
 130 #define G(L)    (L->l_G)
 131
 132
 133 /*
 134 ** Union of all collectable objects
 135 */
 136 union GCObject {
 137   GCheader gch;
 138   union TString ts;
 139   union Udata u;
 140   union Closure cl;
 141   struct Table h;
 142   struct Proto p;
 143   struct UpVal uv;
 144   struct lua_State th;  /* thread */
 145 };
 146
 147
 148 /* macros to convert a GCObject into a specific value */
 149 #define rawgco2ts(o)    check_exp((o)->gch.tt == LUA_TSTRING, &((o)->ts))
 150 #define gco2ts(o)       (&rawgco2ts(o)->tsv)
 151 #define rawgco2u(o)     check_exp((o)->gch.tt == LUA_TUSERDATA, &((o)->u))
 152 #define gco2u(o)        (&rawgco2u(o)->uv)
 153 #define gco2cl(o)       check_exp((o)->gch.tt == LUA_TFUNCTION, &((o)->cl))
 154 #define gco2h(o)        check_exp((o)->gch.tt == LUA_TTABLE, &((o)->h))
 155 #define gco2p(o)        check_exp((o)->gch.tt == LUA_TPROTO, &((o)->p))
 156 #define gco2uv(o)       check_exp((o)->gch.tt == LUA_TUPVAL, &((o)->uv))
 157 #define ngcotouv(o) \
 158         check_exp((o) == NULL || (o)->gch.tt == LUA_TUPVAL, &((o)->uv))
 159 #define gco2th(o)       check_exp((o)->gch.tt == LUA_TTHREAD, &((o)->th))
 160
 161 /* macro to convert any Lua object into a GCObject */
 162 #define obj2gco(v)      (cast(GCObject *, (v)))
 163
 164
 165 LUAI_FUNC lua_State *luaE_newthread (lua_State *L);
 166 LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1);
 167
 168 #endif
 169