commit de3b1c9b53d74de4f22fe75b801cc57e1ba2840e
parent 733c58595bb57541e38275103fade1330aeb839d
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Thu, 13 Feb 2014 12:46:13 -0200
better control for number of finalizers called at each GC cycle
(increases progressively)
Diffstat:
| M | lgc.c | | | 62 | ++++++++++++++++++++++++++++++++++++++++---------------------- |
| M | lgc.h | | | 5 | +++-- |
| M | lstate.c | | | 13 | +++++++------ |
| M | lstate.h | | | 3 | ++- |
4 files changed, 52 insertions(+), 31 deletions(-)
diff --git a/lgc.c b/lgc.c
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.c,v 2.170 2014/02/11 12:28:47 roberto Exp roberto $
+** $Id: lgc.c,v 2.171 2014/02/13 12:11:34 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -33,8 +33,8 @@
/* maximum number of elements to sweep in each single step */
#define GCSWEEPMAX (cast_int((GCSTEPSIZE / GCSWEEPCOST) / 4))
-/* maximum number of finalizers to call in each GC step */
-#define GCFINALIZENUM 4
+/* cost of calling one finalizer */
+#define GCFINALIZECOST GCSWEEPCOST
/*
@@ -960,6 +960,7 @@ static l_mem atomic (lua_State *L) {
origweak = g->weak; origall = g->allweak;
work += g->GCmemtrav; /* stop counting (objects being finalized) */
separatetobefnz(g, 0); /* separate objects to be finalized */
+ g->gcfinnum = 1; /* there may be objects to be finalized */
markbeingfnz(g); /* mark objects that will be finalized */
propagateall(g); /* remark, to propagate 'resurrection' */
work -= g->GCmemtrav; /* restart counting */
@@ -1014,7 +1015,7 @@ static lu_mem singlestep (lua_State *L) {
int sw;
propagateall(g); /* make sure gray list is empty */
g->GCestimate = g->GCmemtrav; /* save what was counted */;
- work = atomic(L); /* add what was traversed by 'atomic' */
+ work = atomic(L); /* work is what was traversed by 'atomic' */
g->GCestimate += work; /* estimate of total memory traversed */
sw = entersweep(L);
return work + sw * GCSWEEPCOST;
@@ -1034,8 +1035,13 @@ static lu_mem singlestep (lua_State *L) {
case GCSswpend: { /* finish sweeps */
makewhite(g, obj2gco(g->mainthread)); /* sweep main thread */
checkSizes(L, g);
+ g->gcstate = GCScallfin;
+ return 0;
+ }
+ case GCScallfin: { /* state to finish calling finalizers */
+ /* do nothing here; should be handled by 'luaC_forcestep' */
g->gcstate = GCSpause; /* finish collection */
- return GCSWEEPCOST;
+ return 0;
}
default: lua_assert(0); return 0;
}
@@ -1053,7 +1059,25 @@ void luaC_runtilstate (lua_State *L, int statesmask) {
}
-static void incstep (lua_State *L) {
+/*
+** run a few finalizers
+*/
+static int dosomefinalization (lua_State *L) {
+ global_State *g = G(L);
+ unsigned int i;
+ lua_assert(!g->tobefnz || g->gcfinnum > 0);
+ for (i = 0; g->tobefnz && i < g->gcfinnum; i++)
+ GCTM(L, 1); /* call one finalizer */
+ g->gcfinnum = (!g->tobefnz) ? 0 /* nothing more to finalize? */
+ : g->gcfinnum * 2; /* else call a few more next time */
+ return i;
+}
+
+
+/*
+** performs a basic GC step
+*/
+void luaC_forcestep (lua_State *L) {
global_State *g = G(L);
l_mem debt = g->GCdebt;
int stepmul = g->gcstepmul;
@@ -1061,33 +1085,27 @@ static void incstep (lua_State *L) {
/* convert debt from Kb to 'work units' (avoid zero debt and overflows) */
debt = (debt / STEPMULADJ) + 1;
debt = (debt < MAX_LMEM / stepmul) ? debt * stepmul : MAX_LMEM;
- do { /* always perform at least one single step */
- lu_mem work = singlestep(L); /* do some work */
- debt -= work;
+ do {
+ if (g->gcstate == GCScallfin && g->tobefnz) {
+ unsigned int n = dosomefinalization(L);
+ debt -= (n * GCFINALIZECOST);
+ }
+ else { /* perform one single step */
+ lu_mem work = singlestep(L);
+ debt -= work;
+ }
} while (debt > -GCSTEPSIZE && g->gcstate != GCSpause);
if (g->gcstate == GCSpause)
setpause(g, g->GCestimate); /* pause until next cycle */
else {
debt = (debt / stepmul) * STEPMULADJ; /* convert 'work units' to Kb */
luaE_setdebt(g, debt);
+ dosomefinalization(L);
}
}
/*
-** performs a basic GC step
-*/
-void luaC_forcestep (lua_State *L) {
- global_State *g = G(L);
- int i;
- incstep(L);
- /* run a few finalizers (or all of them at the end of a collect cycle) */
- for (i = 0; g->tobefnz && (i < GCFINALIZENUM || g->gcstate == GCSpause); i++)
- GCTM(L, 1); /* call one finalizer */
-}
-
-
-/*
** performs a basic GC step when collector is running
*/
void luaC_step (lua_State *L) {
diff --git a/lgc.h b/lgc.h
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.h,v 2.77 2014/02/11 12:18:12 roberto Exp roberto $
+** $Id: lgc.h,v 2.78 2014/02/13 12:11:34 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -43,7 +43,8 @@
#define GCSswpfinobj 4
#define GCSswptobefnz 5
#define GCSswpend 6
-#define GCSpause 7
+#define GCScallfin 7
+#define GCSpause 8
#define issweepphase(g) \
diff --git a/lstate.c b/lstate.c
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.c,v 2.117 2014/02/11 12:18:12 roberto Exp roberto $
+** $Id: lstate.c,v 2.118 2014/02/13 12:11:34 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -214,10 +214,10 @@ static void f_luaopen (lua_State *L, void *ud) {
/*
-** preinitialize a state with consistent values without allocating
+** preinitialize a thread with consistent values without allocating
** any memory (to avoid errors)
*/
-static void preinit_state (lua_State *L, global_State *g) {
+static void preinit_thread (lua_State *L, global_State *g) {
G(L) = g;
L->stack = NULL;
L->ci = NULL;
@@ -264,7 +264,7 @@ LUA_API lua_State *lua_newthread (lua_State *L) {
g->mainthread->next = obj2gco(L1);
setthvalue(L, L->top, L1);
api_incr_top(L);
- preinit_state(L1, g);
+ preinit_thread(L1, g);
L1->hookmask = L->hookmask;
L1->basehookcount = L->basehookcount;
L1->hook = L->hook;
@@ -298,8 +298,7 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
L->tt = LUA_TTHREAD;
g->currentwhite = bitmask(WHITE0BIT);
L->marked = luaC_white(g);
- g->gckind = KGC_NORMAL;
- preinit_state(L, g);
+ preinit_thread(L, g);
g->frealloc = f;
g->ud = ud;
g->mainthread = L;
@@ -313,12 +312,14 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
g->panic = NULL;
g->version = NULL;
g->gcstate = GCSpause;
+ g->gckind = KGC_NORMAL;
g->allgc = g->finobj = g->tobefnz = g->fixedgc = NULL;
g->sweepgc = NULL;
g->gray = g->grayagain = NULL;
g->weak = g->ephemeron = g->allweak = NULL;
g->totalbytes = sizeof(LG);
g->GCdebt = 0;
+ g->gcfinnum = 0;
g->gcpause = LUAI_GCPAUSE;
g->gcstepmul = LUAI_GCMUL;
for (i=0; i < LUA_NUMTAGS; i++) g->mt[i] = NULL;
diff --git a/lstate.h b/lstate.h
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.h,v 2.98 2014/02/11 12:18:12 roberto Exp roberto $
+** $Id: lstate.h,v 2.99 2014/02/13 12:11:34 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -125,6 +125,7 @@ typedef struct global_State {
GCObject *tobefnz; /* list of userdata to be GC */
GCObject *fixedgc; /* list of objects not to be collected */
Mbuffer buff; /* temporary buffer for string concatenation */
+ unsigned int gcfinnum; /* number of finalizers to call in each GC step */
int gcpause; /* size of pause between successive GCs */
int gcstepmul; /* GC `granularity' */
lua_CFunction panic; /* to be called in unprotected errors */
