2 ** $Id: lgc.h,v 2.15 2005/08/24 16:15:49 roberto Exp $
4 ** See Copyright Notice in lua.h
15 ** Possible states of the Garbage Collector
18 #define GCSpropagate 1
19 #define GCSsweepstring 2
25 ** some userful bit tricks
27 #define resetbits(x,m) ((x) &= cast(lu_byte, ~(m)))
28 #define setbits(x,m) ((x) |= (m))
29 #define testbits(x,m) ((x) & (m))
30 #define bitmask(b) (1<<(b))
31 #define bit2mask(b1,b2) (bitmask(b1) | bitmask(b2))
32 #define l_setbit(x,b) setbits(x, bitmask(b))
33 #define resetbit(x,b) resetbits(x, bitmask(b))
34 #define testbit(x,b) testbits(x, bitmask(b))
35 #define set2bits(x,b1,b2) setbits(x, (bit2mask(b1, b2)))
36 #define reset2bits(x,b1,b2) resetbits(x, (bit2mask(b1, b2)))
37 #define test2bits(x,b1,b2) testbits(x, (bit2mask(b1, b2)))
42 ** Layout for bit use in `marked' field:
43 ** bit 0 - object is white (type 0)
44 ** bit 1 - object is white (type 1)
45 ** bit 2 - object is black
46 ** bit 3 - for userdata: has been finalized
47 ** bit 3 - for tables: has weak keys
48 ** bit 4 - for tables: has weak values
49 ** bit 5 - object is fixed (should not be collected)
50 ** bit 6 - object is "super" fixed (only the main thread)
57 #define FINALIZEDBIT 3
59 #define VALUEWEAKBIT 4
62 #define WHITEBITS bit2mask(WHITE0BIT, WHITE1BIT)
65 #define iswhite(x) test2bits((x)->gch.marked, WHITE0BIT, WHITE1BIT)
66 #define isblack(x) testbit((x)->gch.marked, BLACKBIT)
67 #define isgray(x) (!isblack(x) && !iswhite(x))
69 #define otherwhite(g) (g->currentwhite ^ WHITEBITS)
70 #define isdead(g,v) ((v)->gch.marked & otherwhite(g) & WHITEBITS)
72 #define changewhite(x) ((x)->gch.marked ^= WHITEBITS)
73 #define gray2black(x) l_setbit((x)->gch.marked, BLACKBIT)
75 #define valiswhite(x) (iscollectable(x) && iswhite(gcvalue(x)))
77 #define luaC_white(g) cast(lu_byte, (g)->currentwhite & WHITEBITS)
80 #define luaC_checkGC(L) { \
81 condhardstacktests(luaD_reallocstack(L, L->stacksize - EXTRA_STACK - 1)); \
82 if (G(L)->totalbytes >= G(L)->GCthreshold) \
86 #define luaC_barrier(L,p,v) { if (valiswhite(v) && isblack(obj2gco(p))) \
87 luaC_barrierf(L,obj2gco(p),gcvalue(v)); }
89 #define luaC_barriert(L,t,v) { if (valiswhite(v) && isblack(obj2gco(t))) \
90 luaC_barrierback(L,t); }
92 #define luaC_objbarrier(L,p,o) \
93 { if (iswhite(obj2gco(o)) && isblack(obj2gco(p))) \
94 luaC_barrierf(L,obj2gco(p),obj2gco(o)); }
96 #define luaC_objbarriert(L,t,o) \
97 { if (iswhite(obj2gco(o)) && isblack(obj2gco(t))) luaC_barrierback(L,t); }
99 LUAI_FUNC
size_t luaC_separateudata (lua_State
*L
, int all
);
100 LUAI_FUNC
void luaC_callGCTM (lua_State
*L
);
101 LUAI_FUNC
void luaC_freeall (lua_State
*L
);
102 LUAI_FUNC
void luaC_step (lua_State
*L
);
103 LUAI_FUNC
void luaC_fullgc (lua_State
*L
);
104 LUAI_FUNC
void luaC_link (lua_State
*L
, GCObject
*o
, lu_byte tt
);
105 LUAI_FUNC
void luaC_linkupval (lua_State
*L
, UpVal
*uv
);
106 LUAI_FUNC
void luaC_barrierf (lua_State
*L
, GCObject
*o
, GCObject
*v
);
107 LUAI_FUNC
void luaC_barrierback (lua_State
*L
, Table
*t
);