1/* $NetBSD$ */ 2 3/* 4** Id: lgc.h,v 2.15.1.1 2007/12/27 13:02:25 roberto Exp 5** Garbage Collector 6** See Copyright Notice in lua.h 7*/ 8 9#ifndef lgc_h 10#define lgc_h 11 12 13#include "lobject.h" 14 15 16/* 17** Possible states of the Garbage Collector 18*/ 19#define GCSpause 0 20#define GCSpropagate 1 21#define GCSsweepstring 2 22#define GCSsweep 3 23#define GCSfinalize 4 24 25 26/* 27** some userful bit tricks 28*/ 29#define resetbits(x,m) ((x) &= cast(lu_byte, ~(m))) 30#define setbits(x,m) ((x) |= (m)) 31#define testbits(x,m) ((x) & (m)) 32#define bitmask(b) (1<<(b)) 33#define bit2mask(b1,b2) (bitmask(b1) | bitmask(b2)) 34#define l_setbit(x,b) setbits(x, bitmask(b)) 35#define resetbit(x,b) resetbits(x, bitmask(b)) 36#define testbit(x,b) testbits(x, bitmask(b)) 37#define set2bits(x,b1,b2) setbits(x, (bit2mask(b1, b2))) 38#define reset2bits(x,b1,b2) resetbits(x, (bit2mask(b1, b2))) 39#define test2bits(x,b1,b2) testbits(x, (bit2mask(b1, b2))) 40 41 42 43/* 44** Layout for bit use in `marked' field: 45** bit 0 - object is white (type 0) 46** bit 1 - object is white (type 1) 47** bit 2 - object is black 48** bit 3 - for userdata: has been finalized 49** bit 3 - for tables: has weak keys 50** bit 4 - for tables: has weak values 51** bit 5 - object is fixed (should not be collected) 52** bit 6 - object is "super" fixed (only the main thread) 53*/ 54 55 56#define WHITE0BIT 0 57#define WHITE1BIT 1 58#define BLACKBIT 2 59#define FINALIZEDBIT 3 60#define KEYWEAKBIT 3 61#define VALUEWEAKBIT 4 62#define FIXEDBIT 5 63#define SFIXEDBIT 6 64#define WHITEBITS bit2mask(WHITE0BIT, WHITE1BIT) 65 66 67#define iswhite(x) test2bits((x)->gch.marked, WHITE0BIT, WHITE1BIT) 68#define isblack(x) testbit((x)->gch.marked, BLACKBIT) 69#define isgray(x) (!isblack(x) && !iswhite(x)) 70 71#define otherwhite(g) (g->currentwhite ^ WHITEBITS) 72#define isdead(g,v) ((v)->gch.marked & otherwhite(g) & WHITEBITS) 73 74#define changewhite(x) ((x)->gch.marked ^= WHITEBITS) 75#define gray2black(x) l_setbit((x)->gch.marked, BLACKBIT) 76 77#define valiswhite(x) (iscollectable(x) && iswhite(gcvalue(x))) 78 79#define luaC_white(g) cast(lu_byte, (g)->currentwhite & WHITEBITS) 80 81 82#define luaC_checkGC(L) { \ 83 condhardstacktests(luaD_reallocstack(L, L->stacksize - EXTRA_STACK - 1)); \ 84 if (G(L)->totalbytes >= G(L)->GCthreshold) \ 85 luaC_step(L); } 86 87 88#define luaC_barrier(L,p,v) { if (valiswhite(v) && isblack(obj2gco(p))) \ 89 luaC_barrierf(L,obj2gco(p),gcvalue(v)); } 90 91#define luaC_barriert(L,t,v) { if (valiswhite(v) && isblack(obj2gco(t))) \ 92 luaC_barrierback(L,t); } 93 94#define luaC_objbarrier(L,p,o) \ 95 { if (iswhite(obj2gco(o)) && isblack(obj2gco(p))) \ 96 luaC_barrierf(L,obj2gco(p),obj2gco(o)); } 97 98#define luaC_objbarriert(L,t,o) \ 99 { if (iswhite(obj2gco(o)) && isblack(obj2gco(t))) luaC_barrierback(L,t); } 100 101LUAI_FUNC size_t luaC_separateudata (lua_State *L, int all); 102LUAI_FUNC void luaC_callGCTM (lua_State *L); 103LUAI_FUNC void luaC_freeall (lua_State *L); 104LUAI_FUNC void luaC_step (lua_State *L); 105LUAI_FUNC void luaC_fullgc (lua_State *L); 106LUAI_FUNC void luaC_link (lua_State *L, GCObject *o, lu_byte tt); 107LUAI_FUNC void luaC_linkupval (lua_State *L, UpVal *uv); 108LUAI_FUNC void luaC_barrierf (lua_State *L, GCObject *o, GCObject *v); 109LUAI_FUNC void luaC_barrierback (lua_State *L, Table *t); 110 111 112#endif 113