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Diffstat (limited to 'source/luametatex/source/luacore/lua54/src/lgc.h')
-rw-r--r-- | source/luametatex/source/luacore/lua54/src/lgc.h | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/source/luametatex/source/luacore/lua54/src/lgc.h b/source/luametatex/source/luacore/lua54/src/lgc.h new file mode 100644 index 000000000..4a125634b --- /dev/null +++ b/source/luametatex/source/luacore/lua54/src/lgc.h @@ -0,0 +1,199 @@ +/* +** $Id: lgc.h $ +** Garbage Collector +** See Copyright Notice in lua.h +*/ + +#ifndef lgc_h +#define lgc_h + + +#include "lobject.h" +#include "lstate.h" + +/* +** Collectable objects may have one of three colors: white, which means +** the object is not marked; gray, which means the object is marked, but +** its references may be not marked; and black, which means that the +** object and all its references are marked. The main invariant of the +** garbage collector, while marking objects, is that a black object can +** never point to a white one. Moreover, any gray object must be in a +** "gray list" (gray, grayagain, weak, allweak, ephemeron) so that it +** can be visited again before finishing the collection cycle. (Open +** upvalues are an exception to this rule.) These lists have no meaning +** when the invariant is not being enforced (e.g., sweep phase). +*/ + + +/* +** Possible states of the Garbage Collector +*/ +#define GCSpropagate 0 +#define GCSenteratomic 1 +#define GCSatomic 2 +#define GCSswpallgc 3 +#define GCSswpfinobj 4 +#define GCSswptobefnz 5 +#define GCSswpend 6 +#define GCScallfin 7 +#define GCSpause 8 + + +#define issweepphase(g) \ + (GCSswpallgc <= (g)->gcstate && (g)->gcstate <= GCSswpend) + + +/* +** macro to tell when main invariant (white objects cannot point to black +** ones) must be kept. During a collection, the sweep +** phase may break the invariant, as objects turned white may point to +** still-black objects. The invariant is restored when sweep ends and +** all objects are white again. +*/ + +#define keepinvariant(g) ((g)->gcstate <= GCSatomic) + + +/* +** some useful bit tricks +*/ +#define resetbits(x,m) ((x) &= cast_byte(~(m))) +#define setbits(x,m) ((x) |= (m)) +#define testbits(x,m) ((x) & (m)) +#define bitmask(b) (1<<(b)) +#define bit2mask(b1,b2) (bitmask(b1) | bitmask(b2)) +#define l_setbit(x,b) setbits(x, bitmask(b)) +#define resetbit(x,b) resetbits(x, bitmask(b)) +#define testbit(x,b) testbits(x, bitmask(b)) + + +/* +** Layout for bit use in 'marked' field. First three bits are +** used for object "age" in generational mode. Last bit is used +** by tests. +*/ +#define WHITE0BIT 3 /* object is white (type 0) */ +#define WHITE1BIT 4 /* object is white (type 1) */ +#define BLACKBIT 5 /* object is black */ +#define FINALIZEDBIT 6 /* object has been marked for finalization */ + +#define TESTBIT 7 + + + +#define WHITEBITS bit2mask(WHITE0BIT, WHITE1BIT) + + +#define iswhite(x) testbits((x)->marked, WHITEBITS) +#define isblack(x) testbit((x)->marked, BLACKBIT) +#define isgray(x) /* neither white nor black */ \ + (!testbits((x)->marked, WHITEBITS | bitmask(BLACKBIT))) + +#define tofinalize(x) testbit((x)->marked, FINALIZEDBIT) + +#define otherwhite(g) ((g)->currentwhite ^ WHITEBITS) +#define isdeadm(ow,m) ((m) & (ow)) +#define isdead(g,v) isdeadm(otherwhite(g), (v)->marked) + +#define changewhite(x) ((x)->marked ^= WHITEBITS) +#define nw2black(x) \ + check_exp(!iswhite(x), l_setbit((x)->marked, BLACKBIT)) + +#define luaC_white(g) cast_byte((g)->currentwhite & WHITEBITS) + + +/* object age in generational mode */ +#define G_NEW 0 /* created in current cycle */ +#define G_SURVIVAL 1 /* created in previous cycle */ +#define G_OLD0 2 /* marked old by frw. barrier in this cycle */ +#define G_OLD1 3 /* first full cycle as old */ +#define G_OLD 4 /* really old object (not to be visited) */ +#define G_TOUCHED1 5 /* old object touched this cycle */ +#define G_TOUCHED2 6 /* old object touched in previous cycle */ + +#define AGEBITS 7 /* all age bits (111) */ + +#define getage(o) ((o)->marked & AGEBITS) +#define setage(o,a) ((o)->marked = cast_byte(((o)->marked & (~AGEBITS)) | a)) +#define isold(o) (getage(o) > G_SURVIVAL) + +#define changeage(o,f,t) \ + check_exp(getage(o) == (f), (o)->marked ^= ((f)^(t))) + + +/* Default Values for GC parameters */ +#define LUAI_GENMAJORMUL 100 +#define LUAI_GENMINORMUL 20 + +/* wait memory to double before starting new cycle */ +#define LUAI_GCPAUSE 200 + +/* +** some gc parameters are stored divided by 4 to allow a maximum value +** up to 1023 in a 'lu_byte'. +*/ +#define getgcparam(p) ((p) * 4) +#define setgcparam(p,v) ((p) = (v) / 4) + +#define LUAI_GCMUL 100 + +/* how much to allocate before next GC step (log2) */ +#define LUAI_GCSTEPSIZE 13 /* 8 KB */ + + +/* +** Check whether the declared GC mode is generational. While in +** generational mode, the collector can go temporarily to incremental +** mode to improve performance. This is signaled by 'g->lastatomic != 0'. +*/ +#define isdecGCmodegen(g) (g->gckind == KGC_GEN || g->lastatomic != 0) + + +/* +** Control when GC is running: +*/ +#define GCSTPUSR 1 /* bit true when GC stopped by user */ +#define GCSTPGC 2 /* bit true when GC stopped by itself */ +#define GCSTPCLS 4 /* bit true when closing Lua state */ +#define gcrunning(g) ((g)->gcstp == 0) + + +/* +** Does one step of collection when debt becomes positive. 'pre'/'pos' +** allows some adjustments to be done only when needed. macro +** 'condchangemem' is used only for heavy tests (forcing a full +** GC cycle on every opportunity) +*/ +#define luaC_condGC(L,pre,pos) \ + { if (G(L)->GCdebt > 0) { pre; luaC_step(L); pos;}; \ + condchangemem(L,pre,pos); } + +/* more often than not, 'pre'/'pos' are empty */ +#define luaC_checkGC(L) luaC_condGC(L,(void)0,(void)0) + + +#define luaC_barrier(L,p,v) ( \ + (iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ? \ + luaC_barrier_(L,obj2gco(p),gcvalue(v)) : cast_void(0)) + +#define luaC_barrierback(L,p,v) ( \ + (iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ? \ + luaC_barrierback_(L,p) : cast_void(0)) + +#define luaC_objbarrier(L,p,o) ( \ + (isblack(p) && iswhite(o)) ? \ + luaC_barrier_(L,obj2gco(p),obj2gco(o)) : cast_void(0)) + +LUAI_FUNC void luaC_fix (lua_State *L, GCObject *o); +LUAI_FUNC void luaC_freeallobjects (lua_State *L); +LUAI_FUNC void luaC_step (lua_State *L); +LUAI_FUNC void luaC_runtilstate (lua_State *L, int statesmask); +LUAI_FUNC void luaC_fullgc (lua_State *L, int isemergency); +LUAI_FUNC GCObject *luaC_newobj (lua_State *L, int tt, size_t sz); +LUAI_FUNC void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v); +LUAI_FUNC void luaC_barrierback_ (lua_State *L, GCObject *o); +LUAI_FUNC void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt); +LUAI_FUNC void luaC_changemode (lua_State *L, int newmode); + + +#endif |