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** $Id: lstate.h $
** 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).
** Moreover, there is another set of lists that control gray objects.
** These lists are linked by fields 'gclist'. (All objects that
** can become gray have such a field. The field is not the same
** in all objects, but it always has this name.) Any gray object
** must belong to one of these lists, and all objects in these lists
** must be gray:
** 'gray': regular gray objects, still waiting to be visited.
** 'grayagain': objects that must be revisited at the atomic phase.
** That includes
** - black objects got in a write barrier;
** - all kinds of weak tables during propagation phase;
** - all threads.
** 'weak': tables with weak values to be cleared;
** 'ephemeron': ephemeron tables with white->white entries;
** 'allweak': tables with weak keys and/or weak values to be cleared.
** There is also a list 'protogray' for prototypes that need to have
** their caches cleared.
** About 'nCcalls': each thread in Lua (a lua_State) keeps a count of
** how many "C calls" it has in the C stack, to avoid C-stack overflow.
** This count is very rough approximation; it considers only recursive
** functions inside the interpreter, as non-recursive calls can be
** considered using a fixed (although unknown) amount of stack space.
** The proper count also includes the number of CallInfo structures
** allocated by Lua, as a kind of "potential" calls. So, when Lua
** calls a function (and "consumes" one CallInfo), it needs neither to
** increment nor to check 'nCcalls', as its use of C stack is already
** accounted for.
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
/* extra stack space to handle TM calls and some other extras */
#define EXTRA_STACK 5
/* kinds of Garbage Collection */
#define KGC_INC 0 /* incremental gc */
#define KGC_GEN 1 /* generational gc */
typedef struct stringtable {
TString **hash;
int 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 */
union {
struct { /* only for Lua functions */
const Instruction *savedpc;
l_signalT trap;
int nextraargs; /* # of extra arguments in vararg functions */
} 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;
union {
int funcidx; /* called-function index */
int nyield; /* number of values yielded */
struct { /* info about transfered values (for call/return hooks) */
unsigned short ftransfer; /* offset of first value transfered */
unsigned short ntransfer; /* number of values transfered */
} transferinfo;
} u2;
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_C (1<<1) /* call is running a C function */
#define CIST_HOOKED (1<<2) /* call is running a debug hook */
#define CIST_YPCALL (1<<3) /* call is a yieldable protected call */
#define CIST_TAIL (1<<4) /* call was tail called */
#define CIST_HOOKYIELD (1<<5) /* last hook called yielded */
#define CIST_FIN (1<<6) /* call is running a finalizer */
#define CIST_TRAN (1<<7) /* 'ci' has transfer information */
#if defined(LUA_COMPAT_LT_LE)
#define CIST_LEQ (1<<8) /* using __lt for __le */
/* active function is a Lua function */
#define isLua(ci) (!((ci)->callstatus & CIST_C))
/* call is running Lua code (not a hook) */
#define isLuacode(ci) (!((ci)->callstatus & (CIST_C | CIST_HOOKED)))
/* 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 GCestimate; /* an estimate of the non-garbage memory in use */
stringtable strt; /* hash table for strings */
TValue l_registry;
TValue nilvalue; /* a nil value */
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 genminormul; /* control for minor generational collections */
lu_byte genmajormul; /* control for major generational collections */
lu_byte gcrunning; /* true if GC is running */
lu_byte gcemergency; /* true if this is an emergency collection */
lu_byte gcpause; /* size of pause between successive GCs */
lu_byte gcstepmul; /* GC "speed" */
lu_byte gcstepsize; /* (log2 of) GC granularity */
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 *protogray; /* list of prototypes with "new" caches */
GCObject *tobefnz; /* list of userdata to be GC */
GCObject *fixedgc; /* list of objects not to be collected */
/* fields for generational collector */
GCObject *survival; /* start of objects that survived one GC cycle */
GCObject *old; /* start of old objects */
GCObject *reallyold; /* old objects with more than one cycle */
GCObject *finobjsur; /* list of survival objects with finalizers */
GCObject *finobjold; /* list of old objects with finalizers */
GCObject *finobjrold; /* list of really old objects with finalizers */
struct lua_State *twups; /* list of threads with open upvalues */
lua_CFunction panic; /* to be called in unprotected errors */
struct lua_State *mainthread;
TString *memerrmsg; /* message for memory-allocation errors */
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 {
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 + 'nny' */
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 */
struct UpVal upv;
#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))
#define gco2upv(o) \
check_exp(novariant((o)->tt) == LUA_TUPVAL, &((cast_u(o))->upv))
** macro to convert a Lua object into a GCObject
** (The access to 'tt' tries to ensure that 'v' is actually a Lua object.)
#define obj2gco(v) check_exp((v)->tt >= LUA_TSTRING, &(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);
LUAI_FUNC void luaE_incCcalls (lua_State *L);