/*

** $Id: lstate.h,v 2.24.1.2 2008/01/03 15:20:39 roberto Exp $

** Global State

** See Copyright Notice in lua.h

*/

#ifndef lstate_h

#define lstate_h

#include "lua.h"

#include "lobject.h"

#include "ltm.h"

#include "lzio.h"

struct lua_longjmp;  /* defined in ldo.c */

/* table of globals */

#define gt(L)	(&L->l_gt)

/* registry */

#define registry(L)	(&G(L)->l_registry)

/* extra stack space to handle TM calls and some other extras */

#define EXTRA_STACK   5

#define BASIC_CI_SIZE           8

#define BASIC_STACK_SIZE        (2*LUA_MINSTACK)

typedef struct stringtable {

  GCObject **hash;

  lu_int32 nuse;  /* number of elements */

  int size;

} stringtable;

/*

** informations about a call

*/

typedef struct CallInfo {

  StkId base;  /* base for this function */

  StkId func;  /* function index in the stack */

  StkId	top;  /* top for this function */

  const Instruction *savedpc;

  int nresults;  /* expected number of results from this function */

  int tailcalls;  /* number of tail calls lost under this entry */

} CallInfo;

#define curr_func(L)	(clvalue(L->ci->func))

#define ci_func(ci)	(clvalue((ci)->func))

#define f_isLua(ci)	(!ci_func(ci)->c.isC)

#define isLua(ci)	(ttisfunction((ci)->func) && f_isLua(ci))

/*

** `global state', shared by all threads of this state

*/

typedef struct global_State {

  stringtable strt;  /* hash table for strings */

  lua_Alloc frealloc;  /* function to reallocate memory */

  void *ud;         /* auxiliary data to `frealloc' */

  lu_byte currentwhite;

  lu_byte gcstate;  /* state of garbage collector */

  int sweepstrgc;  /* position of sweep in `strt' */

  GCObject *rootgc;  /* list of all collectable objects */

  GCObject **sweepgc;  /* position of sweep in `rootgc' */

  GCObject *gray;  /* list of gray objects */

  GCObject *grayagain;  /* list of objects to be traversed atomically */

  GCObject *weak;  /* list of weak tables (to be cleared) */

  GCObject *tmudata;  /* last element of list of userdata to be GC */

  Mbuffer buff;  /* temporary buffer for string concatentation */

  lu_mem GCthreshold;

  lu_mem totalbytes;  /* number of bytes currently allocated */

  lu_mem estimate;  /* an estimate of number of bytes actually in use */

  lu_mem gcdept;  /* how much GC is `behind schedule' */

  int gcpause;  /* size of pause between successive GCs */

  int gcstepmul;  /* GC `granularity' */

  lua_CFunction panic;  /* to be called in unprotected errors */

  TValue l_registry;

  struct lua_State *mainthread;

  UpVal uvhead;  /* head of double-linked list of all open upvalues */

  struct Table *mt[NUM_TAGS];  /* metatables for basic types */

  TString *tmname[TM_N];  /* array with tag-method names */

} global_State;

/*

** `per thread' state

*/

struct lua_State {

  CommonHeader;

  lu_byte status;

  StkId top;  /* first free slot in the stack */

  StkId base;  /* base of current function */

  global_State *l_G;

  CallInfo *ci;  /* call info for current function */

  const Instruction *savedpc;  /* `savedpc' of current function */

  StkId stack_last;  /* last free slot in the stack */

  StkId stack;  /* stack base */

  CallInfo *end_ci;  /* points after end of ci array*/

  CallInfo *base_ci;  /* array of CallInfo's */

  int stacksize;

  int size_ci;  /* size of array `base_ci' */

  unsigned short nCcalls;  /* number of nested C calls */

  unsigned short baseCcalls;  /* nested C calls when resuming coroutine */

  lu_byte hookmask;

  lu_byte allowhook;

  int basehookcount;

  int hookcount;

  lua_Hook hook;

  TValue l_gt;  /* table of globals */

  TValue env;  /* temporary place for environments */

  GCObject *openupval;  /* list of open upvalues in this stack */

  GCObject *gclist;

  struct lua_longjmp *errorJmp;  /* current error recover point */

  ptrdiff_t errfunc;  /* current error handling function (stack index) */

};

#define G(L)	(L->l_G)

/*

** Union of all collectable objects

*/

union GCObject {

  GCheader gch;

  union TString ts;

  union Udata u;

  union Closure cl;

  struct Table h;

  struct Proto p;

  struct UpVal uv;

  struct lua_State th;  /* thread */

};

/* macros to convert a GCObject into a specific value */

#define rawgco2ts(o)	check_exp((o)->gch.tt == LUA_TSTRING, &((o)->ts))

#define gco2ts(o)	(&rawgco2ts(o)->tsv)

#define rawgco2u(o)	check_exp((o)->gch.tt == LUA_TUSERDATA, &((o)->u))

#define gco2u(o)	(&rawgco2u(o)->uv)

#define gco2cl(o)	check_exp((o)->gch.tt == LUA_TFUNCTION, &((o)->cl))

#define gco2h(o)	check_exp((o)->gch.tt == LUA_TTABLE, &((o)->h))

#define gco2p(o)	check_exp((o)->gch.tt == LUA_TPROTO, &((o)->p))

#define gco2uv(o)	check_exp((o)->gch.tt == LUA_TUPVAL, &((o)->uv))

#define ngcotouv(o) \

	check_exp((o) == NULL || (o)->gch.tt == LUA_TUPVAL, &((o)->uv))

#define gco2th(o)	check_exp((o)->gch.tt == LUA_TTHREAD, &((o)->th))

/* macro to convert any Lua object into a GCObject */

#define obj2gco(v)	(cast(GCObject *, (v)))

LUAI_FUNC lua_State *luaE_newthread (lua_State *L);

LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1);

#endif