/*

** $Id: lstate.h,v 2.82.1.1 2013/04/12 18:48:47 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"

/*

** Some notes about garbage-collected objects: All objects in Lua must

** be kept somehow accessible until being freed.

**

** Lua keeps most objects linked in list g->allgc. The link uses field

** 'next' of the CommonHeader.

**

** Strings are kept in several lists headed by the array g->strt.hash.

**

** Open upvalues are not subject to independent garbage collection. They

** are collected together with their respective threads. Lua keeps a

** double-linked list with all open upvalues (g->uvhead) so that it can

** mark objects referred by them. (They are always gray, so they must

** be remarked in the atomic step. Usually their contents would be marked

** when traversing the respective threads, but the thread may already be

** dead, while the upvalue is still accessible through closures.)

**

** Objects with finalizers are kept in the list g->finobj.

**

** The list g->tobefnz links all objects being finalized.

*/

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

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

#define EXTRA_STACK 5

#define BASIC_STACK_SIZE (2*LUA_MINSTACK)

/* kinds of Garbage Collection */

#define KGC_NORMAL 0

#define KGC_EMERGENCY 1 /* gc was forced by an allocation failure */

#define KGC_GEN 2 /* generational collection */

typedef struct stringtable {

GCObject **hash;

lu_int32 nuse; /* number of elements */

int size;

} stringtable;

/*

** information about a call

*/

typedef struct CallInfo {

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

StkId top; /* top for this function */

struct CallInfo *previous, *next; /* dynamic call link */

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

lu_byte callstatus;

ptrdiff_t extra;

union {

struct { /* only for Lua functions */

StkId base; /* base for this function */

const Instruction *savedpc;

} l;

struct { /* only for C functions */

int ctx; /* context info. in case of yields */

lua_CFunction k; /* continuation in case of yields */

ptrdiff_t old_errfunc;

lu_byte old_allowhook;

lu_byte status;

} c;

} u;

} CallInfo;

/*

** Bits in CallInfo status

*/

#define CIST_LUA (1<<0) /* call is running a Lua function */

#define CIST_HOOKED (1<<1) /* call is running a debug hook */

#define CIST_REENTRY (1<<2) /* call is running on same invocation of

luaV_execute of previous call */

#define CIST_YIELDED (1<<3) /* call reentered after suspension */

#define CIST_YPCALL (1<<4) /* call is a yieldable protected call */

#define CIST_STAT (1<<5) /* call has an error status (pcall) */

#define CIST_TAIL (1<<6) /* call was tail called */

#define CIST_HOOKYIELD (1<<7) /* last hook called yielded */

#define isLua(ci) ((ci)->callstatus & CIST_LUA)

/*

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

*/

typedef struct global_State {

lua_Alloc frealloc; /* function to reallocate memory */

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

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

l_mem GCdebt; /* bytes allocated not yet compensated by the collector */

lu_mem GCmemtrav; /* memory traversed by the GC */

lu_mem GCestimate; /* an estimate of the non-garbage memory in use */

stringtable strt; /* hash table for strings */

TValue l_registry;

unsigned int seed; /* randomized seed for hashes */

lu_byte currentwhite;

lu_byte gcstate; /* state of garbage collector */

lu_byte gckind; /* kind of GC running */

lu_byte gcrunning; /* true if GC is running */

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

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

GCObject *finobj; /* list of collectable objects with finalizers */

GCObject **sweepgc; /* current position of sweep in list 'allgc' */

GCObject **sweepfin; /* current position of sweep in list 'finobj' */

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

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

GCObject *weak; /* list of tables with weak values */

GCObject *ephemeron; /* list of ephemeron tables (weak keys) */

GCObject *allweak; /* list of all-weak tables */

GCObject *tobefnz; /* list of userdata to be GC */

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

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

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

int gcmajorinc; /* pause between major collections (only in gen. mode) */

int gcstepmul; /* GC `granularity' */

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

struct lua_State *mainthread;

const lua_Number *version; /* pointer to version number */

TString *memerrmsg; /* memory-error message */

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

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

} global_State;

/*

** `per thread' state

*/

struct lua_State {

CommonHeader;

lu_byte status;

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

global_State *l_G;

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

const Instruction *oldpc; /* last pc traced */

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

StkId stack; /* stack base */

int stacksize;

unsigned short nny; /* number of non-yieldable calls in stack */

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

lu_byte hookmask;

lu_byte allowhook;

int basehookcount;

int hookcount;

lua_Hook hook;

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) */

CallInfo base_ci; /* CallInfo for first level (C calling Lua) */

};

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

/*

** Union of all collectable objects

*/

union GCObject {

GCheader gch; /* common header */

union TString ts;

union Udata u;

union Closure cl;

struct Table h;

struct Proto p;

struct UpVal uv;

struct lua_State th; /* thread */

};

#define gch(o) (&(o)->gch)

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

#define rawgco2ts(o) \

check_exp(novariant((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 gco2lcl(o) check_exp((o)->gch.tt == LUA_TLCL, &((o)->cl.l))

#define gco2ccl(o) check_exp((o)->gch.tt == LUA_TCCL, &((o)->cl.c))

#define gco2cl(o) \

check_exp(novariant((o)->gch.tt) == LUA_TFUNCTION, &((o)->cl))

#define gco2t(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 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)))

/* actual number of total bytes allocated */

#define gettotalbytes(g) ((g)->totalbytes + (g)->GCdebt)

LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt);

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

LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L);

LUAI_FUNC void luaE_freeCI (lua_State *L);

#endif