/* ** $Id: lstate.h,v 2.133.1.1 2017/04/19 17:39:34 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). ** ** 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. ** The last three lists are used only during the atomic phase. */ 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 #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' */ int gcmlock; /* memory lock new objects - fixedgc */ 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