1 /* $NetBSD: lstate.h,v 1.9 2018/08/04 17:30:01 alnsn Exp $ */ 2 3 /* 4 ** Id: lstate.h,v 2.133.1.1 2017/04/19 17:39:34 roberto Exp 5 ** Global State 6 ** See Copyright Notice in lua.h 7 */ 8 9 #ifndef lstate_h 10 #define lstate_h 11 12 #include "lua.h" 13 14 #include "lobject.h" 15 #include "ltm.h" 16 #include "lzio.h" 17 18 19 /* 20 21 ** Some notes about garbage-collected objects: All objects in Lua must 22 ** be kept somehow accessible until being freed, so all objects always 23 ** belong to one (and only one) of these lists, using field 'next' of 24 ** the 'CommonHeader' for the link: 25 ** 26 ** 'allgc': all objects not marked for finalization; 27 ** 'finobj': all objects marked for finalization; 28 ** 'tobefnz': all objects ready to be finalized; 29 ** 'fixedgc': all objects that are not to be collected (currently 30 ** only small strings, such as reserved words). 31 ** 32 ** Moreover, there is another set of lists that control gray objects. 33 ** These lists are linked by fields 'gclist'. (All objects that 34 ** can become gray have such a field. The field is not the same 35 ** in all objects, but it always has this name.) Any gray object 36 ** must belong to one of these lists, and all objects in these lists 37 ** must be gray: 38 ** 39 ** 'gray': regular gray objects, still waiting to be visited. 40 ** 'grayagain': objects that must be revisited at the atomic phase. 41 ** That includes 42 ** - black objects got in a write barrier; 43 ** - all kinds of weak tables during propagation phase; 44 ** - all threads. 45 ** 'weak': tables with weak values to be cleared; 46 ** 'ephemeron': ephemeron tables with white->white entries; 47 ** 'allweak': tables with weak keys and/or weak values to be cleared. 48 ** The last three lists are used only during the atomic phase. 49 50 */ 51 52 53 struct lua_longjmp; /* defined in ldo.c */ 54 55 56 /* 57 ** Atomic type (relative to signals) to better ensure that 'lua_sethook' 58 ** is thread safe 59 */ 60 #if !defined(l_signalT) 61 #include <signal.h> 62 #define l_signalT sig_atomic_t 63 #endif 64 65 66 /* extra stack space to handle TM calls and some other extras */ 67 #define EXTRA_STACK 5 68 69 70 #define BASIC_STACK_SIZE (2*LUA_MINSTACK) 71 72 73 /* kinds of Garbage Collection */ 74 #define KGC_NORMAL 0 75 #define KGC_EMERGENCY 1 /* gc was forced by an allocation failure */ 76 77 78 typedef struct stringtable { 79 TString **hash; 80 int nuse; /* number of elements */ 81 int size; 82 } stringtable; 83 84 85 /* 86 ** Information about a call. 87 ** When a thread yields, 'func' is adjusted to pretend that the 88 ** top function has only the yielded values in its stack; in that 89 ** case, the actual 'func' value is saved in field 'extra'. 90 ** When a function calls another with a continuation, 'extra' keeps 91 ** the function index so that, in case of errors, the continuation 92 ** function can be called with the correct top. 93 */ 94 typedef struct CallInfo { 95 StkId func; /* function index in the stack */ 96 StkId top; /* top for this function */ 97 struct CallInfo *previous, *next; /* dynamic call link */ 98 union { 99 struct { /* only for Lua functions */ 100 StkId base; /* base for this function */ 101 const Instruction *savedpc; 102 } l; 103 struct { /* only for C functions */ 104 lua_KFunction k; /* continuation in case of yields */ 105 ptrdiff_t old_errfunc; 106 lua_KContext ctx; /* context info. in case of yields */ 107 } c; 108 } u; 109 ptrdiff_t extra; 110 short nresults; /* expected number of results from this function */ 111 unsigned short callstatus; 112 } CallInfo; 113 114 115 /* 116 ** Bits in CallInfo status 117 */ 118 #define CIST_OAH (1<<0) /* original value of 'allowhook' */ 119 #define CIST_LUA (1<<1) /* call is running a Lua function */ 120 #define CIST_HOOKED (1<<2) /* call is running a debug hook */ 121 #define CIST_FRESH (1<<3) /* call is running on a fresh invocation 122 of luaV_execute */ 123 #define CIST_YPCALL (1<<4) /* call is a yieldable protected call */ 124 #define CIST_TAIL (1<<5) /* call was tail called */ 125 #define CIST_HOOKYIELD (1<<6) /* last hook called yielded */ 126 #define CIST_LEQ (1<<7) /* using __lt for __le */ 127 #define CIST_FIN (1<<8) /* call is running a finalizer */ 128 129 #define isLua(ci) ((ci)->callstatus & CIST_LUA) 130 131 /* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */ 132 #define setoah(st,v) ((st) = ((st) & ~CIST_OAH) | (v)) 133 #define getoah(st) ((st) & CIST_OAH) 134 135 136 /* 137 ** 'global state', shared by all threads of this state 138 */ 139 typedef struct global_State { 140 lua_Alloc frealloc; /* function to reallocate memory */ 141 void *ud; /* auxiliary data to 'frealloc' */ 142 l_mem totalbytes; /* number of bytes currently allocated - GCdebt */ 143 l_mem GCdebt; /* bytes allocated not yet compensated by the collector */ 144 lu_mem GCmemtrav; /* memory traversed by the GC */ 145 lu_mem GCestimate; /* an estimate of the non-garbage memory in use */ 146 stringtable strt; /* hash table for strings */ 147 TValue l_registry; 148 unsigned int seed; /* randomized seed for hashes */ 149 lu_byte currentwhite; 150 lu_byte gcstate; /* state of garbage collector */ 151 lu_byte gckind; /* kind of GC running */ 152 lu_byte gcrunning; /* true if GC is running */ 153 GCObject *allgc; /* list of all collectable objects */ 154 GCObject **sweepgc; /* current position of sweep in list */ 155 GCObject *finobj; /* list of collectable objects with finalizers */ 156 GCObject *gray; /* list of gray objects */ 157 GCObject *grayagain; /* list of objects to be traversed atomically */ 158 GCObject *weak; /* list of tables with weak values */ 159 GCObject *ephemeron; /* list of ephemeron tables (weak keys) */ 160 GCObject *allweak; /* list of all-weak tables */ 161 GCObject *tobefnz; /* list of userdata to be GC */ 162 GCObject *fixedgc; /* list of objects not to be collected */ 163 struct lua_State *twups; /* list of threads with open upvalues */ 164 unsigned int gcfinnum; /* number of finalizers to call in each GC step */ 165 int gcpause; /* size of pause between successive GCs */ 166 int gcstepmul; /* GC 'granularity' */ 167 lua_CFunction panic; /* to be called in unprotected errors */ 168 struct lua_State *mainthread; 169 const lua_Number *version; /* pointer to version number */ 170 TString *memerrmsg; /* memory-error message */ 171 TString *tmname[TM_N]; /* array with tag-method names */ 172 struct Table *mt[LUA_NUMTAGS]; /* metatables for basic types */ 173 TString *strcache[STRCACHE_N][STRCACHE_M]; /* cache for strings in API */ 174 } global_State; 175 176 177 /* 178 ** 'per thread' state 179 */ 180 struct lua_State { 181 CommonHeader; 182 unsigned short nci; /* number of items in 'ci' list */ 183 lu_byte status; 184 StkId top; /* first free slot in the stack */ 185 global_State *l_G; 186 CallInfo *ci; /* call info for current function */ 187 const Instruction *oldpc; /* last pc traced */ 188 StkId stack_last; /* last free slot in the stack */ 189 StkId stack; /* stack base */ 190 UpVal *openupval; /* list of open upvalues in this stack */ 191 GCObject *gclist; 192 struct lua_State *twups; /* list of threads with open upvalues */ 193 struct lua_longjmp *errorJmp; /* current error recover point */ 194 CallInfo base_ci; /* CallInfo for first level (C calling Lua) */ 195 volatile lua_Hook hook; 196 ptrdiff_t errfunc; /* current error handling function (stack index) */ 197 int stacksize; 198 int basehookcount; 199 int hookcount; 200 unsigned short nny; /* number of non-yieldable calls in stack */ 201 unsigned short nCcalls; /* number of nested C calls */ 202 l_signalT hookmask; 203 lu_byte allowhook; 204 }; 205 206 207 #define G(L) (L->l_G) 208 209 210 /* 211 ** Union of all collectable objects (only for conversions) 212 */ 213 union GCUnion { 214 GCObject gc; /* common header */ 215 struct TString ts; 216 struct Udata u; 217 union Closure cl; 218 struct Table h; 219 struct Proto p; 220 struct lua_State th; /* thread */ 221 }; 222 223 224 #define cast_u(o) cast(union GCUnion *, (o)) 225 226 /* macros to convert a GCObject into a specific value */ 227 #define gco2ts(o) \ 228 check_exp(novariant((o)->tt) == LUA_TSTRING, &((cast_u(o))->ts)) 229 #define gco2u(o) check_exp((o)->tt == LUA_TUSERDATA, &((cast_u(o))->u)) 230 #define gco2lcl(o) check_exp((o)->tt == LUA_TLCL, &((cast_u(o))->cl.l)) 231 #define gco2ccl(o) check_exp((o)->tt == LUA_TCCL, &((cast_u(o))->cl.c)) 232 #define gco2cl(o) \ 233 check_exp(novariant((o)->tt) == LUA_TFUNCTION, &((cast_u(o))->cl)) 234 #define gco2t(o) check_exp((o)->tt == LUA_TTABLE, &((cast_u(o))->h)) 235 #define gco2p(o) check_exp((o)->tt == LUA_TPROTO, &((cast_u(o))->p)) 236 #define gco2th(o) check_exp((o)->tt == LUA_TTHREAD, &((cast_u(o))->th)) 237 238 239 /* macro to convert a Lua object into a GCObject */ 240 #define obj2gco(v) \ 241 check_exp(novariant((v)->tt) < LUA_TDEADKEY, (&(cast_u(v)->gc))) 242 243 244 /* actual number of total bytes allocated */ 245 #define gettotalbytes(g) cast(lu_mem, (g)->totalbytes + (g)->GCdebt) 246 247 LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt); 248 LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1); 249 LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L); 250 LUAI_FUNC void luaE_freeCI (lua_State *L); 251 LUAI_FUNC void luaE_shrinkCI (lua_State *L); 252 253 254 #endif 255 256