/*
** $Id: lstate.h,v 2.133 2016/12/22 13:08:50 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, so all objects always
** belong to one (and only one) of these lists, using field 'next' of
** the 'CommonHeader' for the link:
**
** 'allgc': all objects not marked for finalization;
** 'finobj': all objects marked for finalization;
** 'tobefnz': all objects ready to be finalized;
** 'fixedgc': all objects that are not to be collected (currently
** only small strings, such as reserved words).
*/
struct lua_longjmp; /* defined in ldo.c */
/*
** Atomic type (relative to signals) to better ensure that 'lua_sethook'
** is thread safe
*/
#if !defined(l_signalT)
#include <signal.h>
#define l_signalT sig_atomic_t
#endif
/* 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 */
typedef struct stringtable {
TString **hash;
int nuse; /* number of elements */
int size;
} stringtable;
/*
** Information about a call.
** When a thread yields, 'func' is adjusted to pretend that the
** top function has only the yielded values in its stack; in that
** case, the actual 'func' value is saved in field 'extra'.
** When a function calls another with a continuation, 'extra' keeps
** the function index so that, in case of errors, the continuation
** function can be called with the correct top.
*/
typedef struct CallInfo {
StkId func; /* function index in the stack */
StkId top; /* top for this function */
struct CallInfo *previous, *next; /* dynamic call link */
union {
struct { /* only for Lua functions */
StkId base; /* base for this function */
const Instruction *savedpc;
} l;
struct { /* only for C functions */
lua_KFunction k; /* continuation in case of yields */
ptrdiff_t old_errfunc;
lua_KContext ctx; /* context info. in case of yields */
} c;
} u;
ptrdiff_t extra;
short nresults; /* expected number of results from this function */
unsigned short callstatus;
} CallInfo;
/*
** Bits in CallInfo status
*/
#define CIST_OAH (1<<0) /* original value of 'allowhook' */
#define CIST_LUA (1<<1) /* call is running a Lua function */
#define CIST_HOOKED (1<<2) /* call is running a debug hook */
#define CIST_FRESH (1<<3) /* call is running on a fresh invocation
of luaV_execute */
#define CIST_YPCALL (1<<4) /* call is a yieldable protected call */
#define CIST_TAIL (1<<5) /* call was tail called */
#define CIST_HOOKYIELD (1<<6) /* last hook called yielded */
#define CIST_LEQ (1<<7) /* using __lt for __le */
#define CIST_FIN (1<<8) /* call is running a finalizer */
#define isLua(ci) ((ci)->callstatus & CIST_LUA)
/* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */
#define setoah(st,v) ((st) = ((st) & ~CIST_OAH) | (v))
#define getoah(st) ((st) & CIST_OAH)
/*
** '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' */
l_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 */
GCObject *allgc; /* list of all collectable objects */
GCObject **sweepgc; /* current position of sweep in list */
GCObject *finobj; /* list of collectable objects with finalizers */
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 */
GCObject *fixedgc; /* list of objects not to be collected */
struct lua_State *twups; /* list of threads with open upvalues */
unsigned int gcfinnum; /* number of finalizers to call in each GC step */
int gcpause; /* size of pause between successive GCs */
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 */
TString *strcache[STRCACHE_N][STRCACHE_M]; /* cache for strings in API */
} global_State;
/*
** 'per thread' state
*/
struct lua_State {
CommonHeader;
unsigned short nci; /* number of items in 'ci' list */
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 */
UpVal *openupval; /* list of open upvalues in this stack */
GCObject *gclist;
struct lua_State *twups; /* list of threads with open upvalues */
struct lua_longjmp *errorJmp; /* current error recover point */
CallInfo base_ci; /* CallInfo for first level (C calling Lua) */
volatile lua_Hook hook;
ptrdiff_t errfunc; /* current error handling function (stack index) */
int stacksize;
int basehookcount;
int hookcount;
unsigned short nny; /* number of non-yieldable calls in stack */
unsigned short nCcalls; /* number of nested C calls */
l_signalT hookmask;
lu_byte allowhook;
};
#define G(L) (L->l_G)
/*
** Union of all collectable objects (only for conversions)
*/
union GCUnion {
GCObject gc; /* common header */
struct TString ts;
struct Udata u;
union Closure cl;
struct Table h;
struct Proto p;
struct lua_State th; /* thread */
};
#define cast_u(o) cast(union GCUnion *, (o))
/* macros to convert a GCObject into a specific value */
#define gco2ts(o) \
check_exp(novariant((o)->tt) == LUA_TSTRING, &((cast_u(o))->ts))
#define gco2u(o) check_exp((o)->tt == LUA_TUSERDATA, &((cast_u(o))->u))
#define gco2lcl(o) check_exp((o)->tt == LUA_TLCL, &((cast_u(o))->cl.l))
#define gco2ccl(o) check_exp((o)->tt == LUA_TCCL, &((cast_u(o))->cl.c))
#define gco2cl(o) \
check_exp(novariant((o)->tt) == LUA_TFUNCTION, &((cast_u(o))->cl))
#define gco2t(o) check_exp((o)->tt == LUA_TTABLE, &((cast_u(o))->h))
#define gco2p(o) check_exp((o)->tt == LUA_TPROTO, &((cast_u(o))->p))
#define gco2th(o) check_exp((o)->tt == LUA_TTHREAD, &((cast_u(o))->th))
/* macro to convert a Lua object into a GCObject */
#define obj2gco(v) \
check_exp(novariant((v)->tt) < LUA_TDEADKEY, (&(cast_u(v)->gc)))
/* actual number of total bytes allocated */
#define gettotalbytes(g) cast(lu_mem, (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);
LUAI_FUNC void luaE_shrinkCI (lua_State *L);
#endif
