commit 5d8b5b9290c932bdfd7dcc670a5af957bdd58392
parent 40565b4a089f44fdcb16f4ed0080b0ca3755e4aa
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 13 Dec 2022 15:45:30 -0300
Changed signal of GC debt
Positive debts seems more natural then negative ones.
Diffstat:
6 files changed, 22 insertions(+), 25 deletions(-)
diff --git a/lapi.c b/lapi.c
@@ -1168,8 +1168,8 @@ LUA_API int lua_gc (lua_State *L, int what, ...) {
g->gcstp = 0; /* allow GC to run (bit GCSTPGC must be zero here) */
if (todo == 0)
todo = 1 << g->gcstepsize; /* standard step size */
- while (todo + g->GCdebt > 0) { /* enough to run a step? */
- todo += g->GCdebt; /* decrement 'todo' (debt is usually negative) */
+ while (todo >= g->GCdebt) { /* enough to run a step? */
+ todo -= g->GCdebt; /* decrement 'todo' */
luaC_step(L); /* run one basic step */
didsomething = 1;
if (g->gckind == KGC_GEN) /* minor collections? */
@@ -1177,8 +1177,8 @@ LUA_API int lua_gc (lua_State *L, int what, ...) {
else if (g->gcstate == GCSpause)
break; /* don't run more than one cycle */
}
- /* add remaining 'todo' to total debt */
- luaE_setdebt(g, todo + g->GCdebt);
+ /* remove remaining 'todo' from total debt */
+ luaE_setdebt(g, g->GCdebt - todo);
g->gcstp = oldstp; /* restore previous state */
if (didsomething && g->gcstate == GCSpause) /* end of cycle? */
res = 1; /* signal it */
diff --git a/lgc.c b/lgc.c
@@ -242,7 +242,7 @@ GCObject *luaC_newobjdt (lua_State *L, int tt, size_t sz, size_t offset) {
global_State *g = G(L);
char *p = cast_charp(luaM_newobject(L, novariant(tt), sz));
GCObject *o = cast(GCObject *, p + offset);
- g->GCdebt++;
+ g->GCdebt--;
o->marked = luaC_white(g);
o->tt = tt;
o->next = g->allgc;
@@ -1034,8 +1034,8 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
*/
static void setpause (global_State *g) {
l_obj threshold = applygcparam(g, gcpause, g->marked);
- l_obj debt = gettotalobjs(g) - threshold;
- if (debt > 0) debt = 0;
+ l_obj debt = threshold - gettotalobjs(g);
+ if (debt < 0) debt = 0;
luaE_setdebt(g, debt);
}
@@ -1285,7 +1285,7 @@ static void atomic2gen (lua_State *L, global_State *g) {
** total number of objects grows 'genminormul'%.
*/
static void setminordebt (global_State *g) {
- luaE_setdebt(g, -applygcparam(g, genminormul, gettotalobjs(g)));
+ luaE_setdebt(g, applygcparam(g, genminormul, gettotalobjs(g)));
}
@@ -1378,13 +1378,13 @@ static void genmajorstep (lua_State *L, global_State *g) {
** Does a generational "step". If the total number of objects grew
** more than 'majormul'% since the last major collection, does a
** major collection. Otherwise, does a minor collection. The test
-** ('GCdebt' > 0) avoids major collections when the step originated from
+** ('GCdebt' != 0) avoids major collections when the step originated from
** 'collectgarbage("step")'.
*/
static void genstep (lua_State *L, global_State *g) {
l_obj majorbase = g->GClastmajor; /* count after last major collection */
l_obj majorinc = applygcparam(g, genmajormul, majorbase);
- if (g->GCdebt > 0 && gettotalobjs(g) > majorbase + majorinc) {
+ if (g->GCdebt != 0 && gettotalobjs(g) > majorbase + majorinc) {
/* do a major collection */
enterinc(g);
g->gckind = KGC_GENMAJOR;
@@ -1605,7 +1605,7 @@ static void incstep (lua_State *L, global_State *g) {
if (g->gcstate == GCSpause)
setpause(g); /* pause until next cycle */
else {
- luaE_setdebt(g, -stepsize);
+ luaE_setdebt(g, stepsize);
}
}
@@ -1618,7 +1618,7 @@ void luaC_step (lua_State *L) {
global_State *g = G(L);
lua_assert(!g->gcemergency);
if (!gcrunning(g)) /* not running? */
- luaE_setdebt(g, -2000);
+ luaE_setdebt(g, 2000);
else {
switch (g->gckind) {
case KGC_INC:
diff --git a/lgc.h b/lgc.h
@@ -175,13 +175,13 @@
/*
-** Does one step of collection when debt becomes positive. 'pre'/'pos'
+** Does one step of collection when debt becomes zero. '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;}; \
+ { if (G(L)->GCdebt <= 0) { pre; luaC_step(L); pos;}; \
condchangemem(L,pre,pos); }
/* more often than not, 'pre'/'pos' are empty */
diff --git a/llimits.h b/llimits.h
@@ -33,6 +33,8 @@ typedef unsigned long lu_mem;
typedef long l_obj;
#endif /* } */
+#define MAX_LOBJ cast(l_obj, ~cast(lu_mem, 0) >> 1)
+
/* chars used as small naturals (so that 'char' is reserved for characters) */
typedef unsigned char lu_byte;
@@ -47,11 +49,6 @@ typedef signed char ls_byte;
: (size_t)(LUA_MAXINTEGER))
-#define MAX_LUMEM ((lu_mem)(~(lu_mem)0))
-
-#define MAX_LMEM ((l_obj)(MAX_LUMEM >> 1))
-
-
#define MAX_INT INT_MAX /* maximum value of an int */
diff --git a/lstate.c b/lstate.c
@@ -89,9 +89,9 @@ static unsigned int luai_makeseed (lua_State *L) {
void luaE_setdebt (global_State *g, l_obj debt) {
l_obj tb = gettotalobjs(g);
lua_assert(tb > 0);
- if (debt < tb - MAX_LMEM)
- debt = tb - MAX_LMEM; /* will make 'totalobjs == MAX_LMEM' */
- g->totalobjs = tb - debt;
+ if (debt > MAX_LOBJ - tb)
+ debt = MAX_LOBJ - tb; /* will make 'totalobjs == MAX_LMEM' */
+ g->totalobjs = tb + debt;
g->GCdebt = debt;
}
diff --git a/lstate.h b/lstate.h
@@ -251,8 +251,8 @@ typedef struct global_State {
lua_Alloc frealloc; /* function to reallocate memory */
void *ud; /* auxiliary data to 'frealloc' */
lu_mem totalbytes; /* number of bytes currently allocated */
- l_obj totalobjs; /* total number of objects allocated - GCdebt */
- l_obj GCdebt; /* bytes allocated not yet compensated by the collector */
+ l_obj totalobjs; /* total number of objects allocated + GCdebt */
+ l_obj GCdebt; /* objects counted but not yet allocated */
l_obj marked; /* number of objects marked in a GC cycle */
l_obj GClastmajor; /* objects at last major collection */
stringtable strt; /* hash table for strings */
@@ -388,7 +388,7 @@ union GCUnion {
/* actual number of total objects allocated */
-#define gettotalobjs(g) ((g)->totalobjs + (g)->GCdebt)
+#define gettotalobjs(g) ((g)->totalobjs - (g)->GCdebt)
LUAI_FUNC void luaE_setdebt (global_State *g, l_obj debt);
