src/lj_gc.h

   1 /*
   2 ** Garbage collector.
   3 ** Copyright (C) 2005-2009 Mike Pall. See Copyright Notice in luajit.h
   4 */
   5
   6 #ifndef _LJ_GC_H
   7 #define _LJ_GC_H
   8
   9 #include "lj_obj.h"
  10
  11 /* Garbage collector states. Order matters. */
  12 enum { GCSpause, GCSpropagate, GCSsweepstring, GCSsweep, GCSfinalize };
  13
  14 /* Bitmasks for marked field of GCobj. */
  15 #define LJ_GC_WHITE0    0x01
  16 #define LJ_GC_WHITE1    0x02
  17 #define LJ_GC_BLACK     0x04
  18 #define LJ_GC_FINALIZED 0x08
  19 #define LJ_GC_WEAKKEY   0x08
  20 #define LJ_GC_WEAKVAL   0x10
  21 #define LJ_GC_FIXED     0x20
  22 #define LJ_GC_SFIXED    0x40
  23
  24 #define LJ_GC_WHITES    (LJ_GC_WHITE0 | LJ_GC_WHITE1)
  25 #define LJ_GC_COLORS    (LJ_GC_WHITES | LJ_GC_BLACK)
  26 #define LJ_GC_WEAK      (LJ_GC_WEAKKEY | LJ_GC_WEAKVAL)
  27
  28 /* Macros to test and set GCobj colors. */
  29 #define iswhite(x)      ((x)->gch.marked & LJ_GC_WHITES)
  30 #define isblack(x)      ((x)->gch.marked & LJ_GC_BLACK)
  31 #define isgray(x)       (!((x)->gch.marked & (LJ_GC_BLACK|LJ_GC_WHITES)))
  32 #define tviswhite(x)    (tvisgcv(x) && iswhite(gcV(x)))
  33 #define otherwhite(g)   (g->gc.currentwhite ^ LJ_GC_WHITES)
  34 #define isdead(g, v)    ((v)->gch.marked & otherwhite(g) & LJ_GC_WHITES)
  35
  36 #define curwhite(g)     ((g)->gc.currentwhite & LJ_GC_WHITES)
  37 #define newwhite(g, x)  (obj2gco(x)->gch.marked = (uint8_t)curwhite(g))
  38 #define flipwhite(x)    ((x)->gch.marked ^= LJ_GC_WHITES)
  39 #define fixstring(s)    ((s)->marked |= LJ_GC_FIXED)
  40
  41 /* Collector. */
  42 LJ_FUNC size_t lj_gc_separateudata(global_State *g, int all);
  43 LJ_FUNC void lj_gc_finalizeudata(lua_State *L);
  44 LJ_FUNC void lj_gc_freeall(global_State *g);
  45 LJ_FUNCA int LJ_FASTCALL lj_gc_step(lua_State *L);
  46 LJ_FUNCA void LJ_FASTCALL lj_gc_step_fixtop(lua_State *L);
  47 LJ_FUNC void LJ_FASTCALL lj_gc_step_jit(lua_State *L, MSize steps);
  48 LJ_FUNC void lj_gc_fullgc(lua_State *L);
  49
  50 /* GC check: drive collector forward if the GC threshold has been reached. */
  51 #define lj_gc_check(L) \
  52   { if (LJ_UNLIKELY(G(L)->gc.total >= G(L)->gc.threshold)) \
  53       lj_gc_step(L); }
  54 #define lj_gc_check_fixtop(L) \
  55   { if (LJ_UNLIKELY(G(L)->gc.total >= G(L)->gc.threshold)) \
  56       lj_gc_step_fixtop(L); }
  57
  58 /* Write barriers. */
  59 LJ_FUNC void lj_gc_barrierback(global_State *g, GCtab *t);
  60 LJ_FUNC void lj_gc_barrierf(global_State *g, GCobj *o, GCobj *v);
  61 LJ_FUNCA void LJ_FASTCALL lj_gc_barrieruv(global_State *g, TValue *tv);
  62 LJ_FUNC void lj_gc_closeuv(global_State *g, GCupval *uv);
  63 LJ_FUNC void lj_gc_barriertrace(global_State *g, void *T);
  64
  65 /* Barrier for stores to table objects. TValue and GCobj variant. */
  66 #define lj_gc_barriert(L, t, tv) \
  67   { if (tviswhite(tv) && isblack(obj2gco(t))) \
  68       lj_gc_barrierback(G(L), (t)); }
  69 #define lj_gc_objbarriert(L, t, o)  \
  70   { if (iswhite(obj2gco(o)) && isblack(obj2gco(t))) \
  71       lj_gc_barrierback(G(L), (t)); }
  72
  73 /* Barrier for stores to any other object. TValue and GCobj variant. */
  74 #define lj_gc_barrier(L, p, tv) \
  75   { if (tviswhite(tv) && isblack(obj2gco(p))) \
  76       lj_gc_barrierf(G(L), obj2gco(p), gcV(tv)); }
  77 #define lj_gc_objbarrier(L, p, o) \
  78   { if (iswhite(obj2gco(o)) && isblack(obj2gco(p))) \
  79       lj_gc_barrierf(G(L), obj2gco(p), obj2gco(o)); }
  80
  81 /* Allocator. */
  82 LJ_FUNC void *lj_mem_realloc(lua_State *L, void *p, MSize osz, MSize nsz);
  83 LJ_FUNC void *lj_mem_newgco(lua_State *L, MSize size);
  84 LJ_FUNC void *lj_mem_grow(lua_State *L, void *p,
  85                           MSize *szp, MSize lim, MSize esz);
  86
  87 #define lj_mem_new(L, s)        lj_mem_realloc(L, NULL, 0, (s))
  88 #define lj_mem_free(g, p, osize) \
  89   (g->gc.total -= (MSize)(osize), g->allocf(g->allocd, (p), (osize), 0))
  90
  91 #define lj_mem_newvec(L, n, t)  ((t *)lj_mem_new(L, (MSize)((n)*sizeof(t))))
  92 #define lj_mem_reallocvec(L, p, on, n, t) \
  93   ((p) = (t *)lj_mem_realloc(L, p, (on)*sizeof(t), (MSize)((n)*sizeof(t))))
  94 #define lj_mem_growvec(L, p, n, m, t) \
  95   ((p) = (t *)lj_mem_grow(L, (p), &(n), (m), (MSize)sizeof(t)))
  96 #define lj_mem_freevec(g, p, n, t)      lj_mem_free(g, (p), (n)*sizeof(t))
  97
  98 #define lj_mem_newobj(L, t)     ((t *)lj_mem_newgco(L, sizeof(t)))
  99 #define lj_mem_newt(L, s, t)    ((t *)lj_mem_new(L, (s)))
 100 #define lj_mem_freet(g, p)      lj_mem_free(g, (p), sizeof(*(p)))
 101
 102 #endif