rpgxef/code/game/lgc.h
Walter Julius Hennecke a39565b783 Integrated RPG-X2 rpgxEF edition into the rpgxEF repo
... not quite content with where the project files lie but it is ok for
now.
... compiling works fine so far (only tested mingw32 right now)
2012-08-04 12:54:37 +02:00

144 lines
5 KiB
C

/*
** $Id: lgc.h,v 2.44 2010/06/30 14:11:17 roberto Exp $
** 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. 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 GCSatomic 1
#define GCSsweepstring 2
#define GCSsweepudata 3
#define GCSsweep 4
#define GCSpause 5
#define issweepphase(g) \
(GCSsweepstring <= (g)->gcstate && (g)->gcstate <= GCSsweep)
#define isgenerational(g) ((g)->gckind == KGC_GEN)
/*
** macro to tell when main invariant (white objects cannot point to black
** ones) must be kept. During a non-generational 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. During a generational collection, the
** invariant must be kept all times.
*/
#define keepinvariant(g) (isgenerational(g) || g->gcstate <= GCSatomic)
#define gcstopped(g) ((g)->GCdebt == MIN_LMEM)
#define stopgc(g) ((g)->GCdebt = MIN_LMEM)
/*
** some useful bit tricks
*/
#define resetbits(x,m) ((x) &= cast(lu_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))
#define set2bits(x,b1,b2) setbits(x, (bit2mask(b1, b2)))
#define reset2bits(x,b1,b2) resetbits(x, (bit2mask(b1, b2)))
/* Layout for bit use in `marked' field: */
#define WHITE0BIT 0 /* object is white (type 0) */
#define WHITE1BIT 1 /* object is white (type 1) */
#define BLACKBIT 2 /* object is black */
#define FINALIZEDBIT 3 /* for userdata: has been finalized */
#define SEPARATED 4 /* " ": it's in 'udgc' list or in 'tobefnz' */
#define FIXEDBIT 5 /* object is fixed (should not be collected) */
#define OLDBIT 6 /* object is old (only in generational mode) */
/* bit 7 is currently used by tests (luaL_checkmemory) */
#define WHITEBITS bit2mask(WHITE0BIT, WHITE1BIT)
#define iswhite(x) testbits((x)->gch.marked, WHITEBITS)
#define isblack(x) testbit((x)->gch.marked, BLACKBIT)
#define isgray(x) /* neither white nor black */ \
(!testbits((x)->gch.marked, WHITEBITS | bitmask(BLACKBIT)))
#define isold(x) testbit((x)->gch.marked, OLDBIT)
/* MOVE OLD rule: whenever an object is moved to the beginning of
a GC list, its old bit must be cleared */
#define resetoldbit(o) resetbit((o)->gch.marked, OLDBIT)
#define otherwhite(g) (g->currentwhite ^ WHITEBITS)
#define isdeadm(ow,m) (!(((m) ^ WHITEBITS) & (ow)))
#define isdead(g,v) isdeadm(otherwhite(g), (v)->gch.marked)
#define changewhite(x) ((x)->gch.marked ^= WHITEBITS)
#define gray2black(x) l_setbit((x)->gch.marked, BLACKBIT)
#define valiswhite(x) (iscollectable(x) && iswhite(gcvalue(x)))
#define luaC_white(g) cast(lu_byte, (g)->currentwhite & WHITEBITS)
#define luaC_checkGC(L) {condchangemem(L); if (G(L)->GCdebt > 0) luaC_step(L);}
#define luaC_barrier(L,p,v) { if (valiswhite(v) && isblack(obj2gco(p))) \
luaC_barrier_(L,obj2gco(p),gcvalue(v)); }
#define luaC_barrierback(L,p,v) { if (valiswhite(v) && isblack(obj2gco(p))) \
luaC_barrierback_(L,p); }
#define luaC_objbarrier(L,p,o) \
{ if (iswhite(obj2gco(o)) && isblack(obj2gco(p))) \
luaC_barrier_(L,obj2gco(p),obj2gco(o)); }
#define luaC_objbarrierback(L,p,o) \
{ if (iswhite(obj2gco(o)) && isblack(obj2gco(p))) luaC_barrierback_(L,p); }
#define luaC_barrierproto(L,p,c) \
{ if (isblack(obj2gco(p))) luaC_barrierproto_(L,p,c); }
LUAI_FUNC void luaC_separateudata (lua_State *L, int all);
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,
GCObject **list, int offset);
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_barrierproto_ (lua_State *L, Proto *p, Closure *c);
LUAI_FUNC void luaC_checkfinalizer (lua_State *L, Udata *u);
LUAI_FUNC void luaC_checkupvalcolor (global_State *g, UpVal *uv);
LUAI_FUNC void luaC_changemode (lua_State *L, int mode);
#endif