--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/liblua/lgc.h	Mon Feb 15 19:49:20 2010 +0000
@@ -0,0 +1,110 @@
+/*
+** $Id: lgc.h,v 2.15.1.1 2007/12/27 13:02:25 roberto Exp $
+** Garbage Collector
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lgc_h
+#define lgc_h
+
+
+#include "lobject.h"
+
+
+/*
+** Possible states of the Garbage Collector
+*/
+#define GCSpause	0
+#define GCSpropagate	1
+#define GCSsweepstring	2
+#define GCSsweep	3
+#define GCSfinalize	4
+
+
+/*
+** some userful 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)))
+#define test2bits(x,b1,b2)	testbits(x, (bit2mask(b1, b2)))
+
+
+
+/*
+** Layout for bit use in `marked' field:
+** bit 0 - object is white (type 0)
+** bit 1 - object is white (type 1)
+** bit 2 - object is black
+** bit 3 - for userdata: has been finalized
+** bit 3 - for tables: has weak keys
+** bit 4 - for tables: has weak values
+** bit 5 - object is fixed (should not be collected)
+** bit 6 - object is "super" fixed (only the main thread)
+*/
+
+
+#define WHITE0BIT	0
+#define WHITE1BIT	1
+#define BLACKBIT	2
+#define FINALIZEDBIT	3
+#define KEYWEAKBIT	3
+#define VALUEWEAKBIT	4
+#define FIXEDBIT	5
+#define SFIXEDBIT	6
+#define WHITEBITS	bit2mask(WHITE0BIT, WHITE1BIT)
+
+
+#define iswhite(x)      test2bits((x)->gch.marked, WHITE0BIT, WHITE1BIT)
+#define isblack(x)      testbit((x)->gch.marked, BLACKBIT)
+#define isgray(x)	(!isblack(x) && !iswhite(x))
+
+#define otherwhite(g)	(g->currentwhite ^ WHITEBITS)
+#define isdead(g,v)	((v)->gch.marked & otherwhite(g) & WHITEBITS)
+
+#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) { \
+  condhardstacktests(luaD_reallocstack(L, L->stacksize - EXTRA_STACK - 1)); \
+  if (G(L)->totalbytes >= G(L)->GCthreshold) \
+	luaC_step(L); }
+
+
+#define luaC_barrier(L,p,v) { if (valiswhite(v) && isblack(obj2gco(p)))  \
+	luaC_barrierf(L,obj2gco(p),gcvalue(v)); }
+
+#define luaC_barriert(L,t,v) { if (valiswhite(v) && isblack(obj2gco(t)))  \
+	luaC_barrierback(L,t); }
+
+#define luaC_objbarrier(L,p,o)  \
+	{ if (iswhite(obj2gco(o)) && isblack(obj2gco(p))) \
+		luaC_barrierf(L,obj2gco(p),obj2gco(o)); }
+
+#define luaC_objbarriert(L,t,o)  \
+   { if (iswhite(obj2gco(o)) && isblack(obj2gco(t))) luaC_barrierback(L,t); }
+
+LUAI_FUNC size_t luaC_separateudata (lua_State *L, int all);
+LUAI_FUNC void luaC_callGCTM (lua_State *L);
+LUAI_FUNC void luaC_freeall (lua_State *L);
+LUAI_FUNC void luaC_step (lua_State *L);
+LUAI_FUNC void luaC_fullgc (lua_State *L);
+LUAI_FUNC void luaC_link (lua_State *L, GCObject *o, lu_byte tt);
+LUAI_FUNC void luaC_linkupval (lua_State *L, UpVal *uv);
+LUAI_FUNC void luaC_barrierf (lua_State *L, GCObject *o, GCObject *v);
+LUAI_FUNC void luaC_barrierback (lua_State *L, Table *t);
+
+
+#endif