Engage!

1 files changed, 202 insertions, 0 deletions

diff --git a/vendor/lua-5.4.8/src/lgc.h b/vendor/lua-5.4.8/src/lgc.h
new file mode 100644
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+++ b/vendor/lua-5.4.8/src/lgc.h
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+/*
+** $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_objbarrier(L,p,o) (  \
+        (isblack(p) && iswhite(o)) ? \
+        luaC_barrier_(L,obj2gco(p),obj2gco(o)) : cast_void(0))
+
+#define luaC_barrier(L,p,v) (  \
+        iscollectable(v) ? luaC_objbarrier(L,p,gcvalue(v)) : cast_void(0))
+
+#define luaC_objbarrierback(L,p,o) (  \
+        (isblack(p) && iswhite(o)) ? luaC_barrierback_(L,p) : cast_void(0))
+
+#define luaC_barrierback(L,p,v) (  \
+        iscollectable(v) ? luaC_objbarrierback(L, p, gcvalue(v)) : 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 GCObject *luaC_newobjdt (lua_State *L, int tt, size_t sz,
+                                                 size_t 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_checkfinalizer (lua_State *L, GCObject *o, Table *mt);
+LUAI_FUNC void luaC_changemode (lua_State *L, int newmode);
+
+
+#endif