commit 5cb128ea540b33dbc6be659d5dfc3c64c57d78d9
parent 74123e96869bdb55d3967036e2bc0c6f9e0550d6
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 23 Mar 2010 17:15:42 -0300
BUG: emergency collector might resize 'strt' (string table) when
creating a new string
+ atomic and markroot steps has some cost
+ full collection must leave collector in proper state when mode
is generational
Diffstat:
M | lgc.c | | | 38 | +++++++++++++++++++++++++++----------- |
1 file changed, 27 insertions(+), 11 deletions(-)
diff --git a/lgc.c b/lgc.c
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.c,v 2.67 2009/12/22 15:32:50 roberto Exp roberto $
+** $Id: lgc.c,v 2.68 2010/03/22 18:28:03 roberto Exp $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -27,6 +27,8 @@
#define GCSWEEPMAX 40
#define GCSWEEPCOST 10
#define GCFINALIZECOST 100
+#define GCROOTCOST 10
+#define GCATOMICCOST 1000
#define maskcolors (~(bitmask(BLACKBIT)|WHITEBITS))
@@ -580,6 +582,8 @@ static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
static void checkSizes (lua_State *L) {
global_State *g = G(L);
+ if (g->gckind == KGC_EMERGENCY)
+ return; /* do not move buffers during emergency collection */
if (g->strt.nuse < cast(lu_int32, g->strt.size)) {
/* string-table size could be the smaller power of 2 larger than 'nuse' */
int size = 1 << luaO_ceillog2(g->strt.nuse);
@@ -739,7 +743,7 @@ static l_mem singlestep (lua_State *L) {
case GCSpause: {
markroot(L); /* start a new collection */
g->gcstate = GCSpropagate;
- return 0;
+ return GCROOTCOST;
}
case GCSpropagate: {
if (g->gray)
@@ -748,22 +752,30 @@ static l_mem singlestep (lua_State *L) {
g->gcstate = GCSatomic; /* finish mark phase */
atomic(L);
g->gcstate = GCSsweepstring;
- return 0;
+ return GCATOMICCOST;
}
}
case GCSsweepstring: {
- sweepwholelist(L, &g->strt.hash[g->sweepstrgc++]);
- if (g->sweepstrgc >= g->strt.size) { /* nothing more to sweep? */
+ if (g->sweepstrgc < g->strt.size) {
+ sweepwholelist(L, &g->strt.hash[g->sweepstrgc++]);
+ return GCSWEEPCOST;
+ }
+ else { /* nothing more to sweep */
g->sweepgc = &g->rootgc;
g->gcstate = GCSsweep; /* sweep all other objects */
+ return 0;
}
- return GCSWEEPCOST;
}
case GCSsweep: {
- g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
- if (*g->sweepgc == NULL) /* nothing more to sweep? */
+ if (*g->sweepgc) {
+ g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
+ return GCSWEEPMAX*GCSWEEPCOST;
+ }
+ else { /* nothing more to sweep */
+ checkSizes(L);
g->gcstate = GCSfinalize; /* end sweep phase */
- return GCSWEEPMAX*GCSWEEPCOST;
+ return 0;
+ }
}
case GCSfinalize: {
if (g->tobefnz) {
@@ -771,7 +783,6 @@ static l_mem singlestep (lua_State *L) {
return GCFINALIZECOST;
}
else {
- checkSizes(L);
g->gcstate = GCSpause; /* end collection */
return 0;
}
@@ -840,18 +851,23 @@ void luaC_fullgc (lua_State *L, int isemergency) {
g->gckind = isemergency ? KGC_EMERGENCY : KGC_FORCED;
if (g->gcstate == GCSpropagate) { /* marking phase? */
/* must sweep all objects to turn them back to white
- (as white does not change, nothing will be collected) */
+ (as white has not changed, nothing will be collected) */
g->sweepstrgc = 0;
g->gcstate = GCSsweepstring;
}
/* finish any pending sweep phase */
luaC_runtilstate(L, ~bit2mask(GCSsweepstring, GCSsweep));
+ lua_assert(g->gcstate == GCSpause || g->gcstate == GCSfinalize);
g->gcstate = GCSpause; /* start a new collection */
/* run collector up to finalizers */
luaC_runtilstate(L, bitmask(GCSfinalize));
g->gckind = origkind;
if (!isemergency) /* do not run finalizers during emergency GC */
luaC_runtilstate(L, bitmask(GCSpause));
+ if (origkind == KGC_GEN) { /* generational mode? */
+ g->gckind = GCSpause; /* collector must be always in... */
+ luaC_runtilstate(L, bitmask(GCSpropagate)); /* ...propagate phase */
+ }
g->GCthreshold = (g->totalbytes/100) * g->gcpause;
}