commit 7ba62e29856458469ae42a7be83856a0ec81e539
parent 8fd28611d5438b913dc7536d175df106727e2584
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 23 Jun 2008 13:51:05 -0300
code reorganization (only changed comments and order of functions)
Diffstat:
| M | lgc.c | | | 357 | +++++++++++++++++++++++++++++++++++++++++++++---------------------------------- |
1 file changed, 203 insertions(+), 154 deletions(-)
diff --git a/lgc.c b/lgc.c
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.c,v 2.43 2008/02/11 15:46:03 roberto Exp roberto $
+** $Id: lgc.c,v 2.44 2008/02/19 18:55:09 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -53,6 +53,15 @@
#define setthreshold(g) (g->GCthreshold = (g->estimate/100) * g->gcpause)
+static void reallymarkobject (global_State *g, GCObject *o);
+
+
+/*
+** {======================================================
+** Generic functions
+** =======================================================
+*/
+
static void linktable (Table *h, GCObject **p) {
h->gclist = *p;
*p = obj2gco(h);
@@ -83,6 +92,65 @@ static int iscleared (const TValue *o, int iskey) {
(ttisuserdata(o) && (!iskey && isfinalized(uvalue(o))));
}
+void luaC_barrierf (lua_State *L, GCObject *o, GCObject *v) {
+ global_State *g = G(L);
+ lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
+ lua_assert(g->gcstate != GCSfinalize && g->gcstate != GCSpause);
+ lua_assert(ttype(gch(o)) != LUA_TTABLE);
+ /* must keep invariant? */
+ if (g->gcstate == GCSpropagate)
+ reallymarkobject(g, v); /* restore invariant */
+ else /* don't mind */
+ makewhite(g, o); /* mark as white just to avoid other barriers */
+}
+
+
+void luaC_barrierback (lua_State *L, Table *t) {
+ global_State *g = G(L);
+ GCObject *o = obj2gco(t);
+ lua_assert(isblack(o) && !isdead(g, o));
+ lua_assert(g->gcstate != GCSfinalize && g->gcstate != GCSpause);
+ black2gray(o); /* make table gray (again) */
+ t->gclist = g->grayagain;
+ g->grayagain = o;
+}
+
+
+void luaC_link (lua_State *L, GCObject *o, lu_byte tt) {
+ global_State *g = G(L);
+ gch(o)->marked = luaC_white(g);
+ gch(o)->tt = tt;
+ gch(o)->next = g->rootgc;
+ g->rootgc = o;
+}
+
+
+void luaC_linkupval (lua_State *L, UpVal *uv) {
+ global_State *g = G(L);
+ GCObject *o = obj2gco(uv);
+ gch(o)->next = g->rootgc; /* link upvalue into `rootgc' list */
+ g->rootgc = o;
+ if (isgray(o)) {
+ if (g->gcstate == GCSpropagate) {
+ gray2black(o); /* closed upvalues need barrier */
+ luaC_barrier(L, uv, uv->v);
+ }
+ else { /* sweep phase: sweep it (turning it into white) */
+ makewhite(g, o);
+ lua_assert(g->gcstate != GCSfinalize && g->gcstate != GCSpause);
+ }
+ }
+}
+
+/* }====================================================== */
+
+
+
+/*
+** {======================================================
+** Mark functions
+** =======================================================
+*/
static void reallymarkobject (global_State *g, GCObject *o) {
lua_assert(iswhite(o) && !isdead(g, o));
@@ -129,36 +197,60 @@ static void reallymarkobject (global_State *g, GCObject *o) {
}
-/* move 'dead' udata that need finalization to list 'tobefnz' */
-size_t luaC_separateudata (lua_State *L, int all) {
+static void markmt (global_State *g) {
+ int i;
+ for (i=0; i<NUM_TAGS; i++)
+ markobject(g, g->mt[i]);
+}
+
+
+static void markbeingfnz (global_State *g) {
+ GCObject *u = g->tobefnz;
+ if (u) {
+ do {
+ u = gch(u)->next;
+ lua_assert(testbit(gch(u)->marked, SEPARATED));
+ lua_assert(!iswhite(u)); /* must be marked, if left from previous GC */
+ makewhite(g, u);
+ reallymarkobject(g, u);
+ } while (u != g->tobefnz);
+ }
+}
+
+
+/* mark root set */
+static void markroot (lua_State *L) {
global_State *g = G(L);
- size_t deadmem = 0;
- GCObject **p = &g->tmudata;
- GCObject *curr;
- while ((curr = *p) != NULL) {
- lua_assert(ttisuserdata(gch(curr)) && !isfinalized(gco2u(curr)));
- lua_assert(testbit(gch(curr)->marked, SEPARATED));
- if (all) makewhite(g, curr); /* if 'all', collect all objects */
- if (!iswhite(curr)) /* not being collected? */
- p = &gch(curr)->next; /* don't bother with it */
- else {
- l_setbit(gch(curr)->marked, FINALIZEDBIT); /* won't be finalized again */
- reallymarkobject(g, curr); /* won't be collected now */
- deadmem += sizeudata(gco2u(curr));
- *p = gch(curr)->next; /* remove 'curr' from 'tmudata' list */
- /* link 'curr' at the end of 'tobefnz' list */
- if (g->tobefnz == NULL) /* list is empty? */
- g->tobefnz = gch(curr)->next = curr; /* creates a circular list */
- else {
- gch(curr)->next = gch(g->tobefnz)->next;
- gch(g->tobefnz)->next = curr;
- g->tobefnz = curr;
- }
- }
+ g->gray = NULL;
+ g->grayagain = NULL;
+ g->weak = g->ephemeron = g->allweak = NULL;
+ markobject(g, g->mainthread);
+ /* make global table be traversed before main stack */
+ markvalue(g, gt(g->mainthread));
+ markvalue(g, registry(L));
+ markmt(g);
+ markbeingfnz(g); /* mark any finalizing userdata left from previous cycle */
+ g->gcstate = GCSpropagate;
+}
+
+
+static void remarkupvals (global_State *g) {
+ UpVal *uv;
+ for (uv = g->uvhead.u.l.next; uv != &g->uvhead; uv = uv->u.l.next) {
+ lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
+ if (isgray(obj2gco(uv)))
+ markvalue(g, uv->v);
}
- return deadmem;
}
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Traverse functions
+** =======================================================
+*/
static void traverseweakvalue (global_State *g, Table *h) {
int i = sizenode(h);
@@ -382,6 +474,14 @@ static size_t propagateall (global_State *g) {
}
+static void traverselistofgrays (global_State *g, GCObject **l) {
+ lua_assert(g->gray == NULL); /* no grays left */
+ g->gray = *l; /* now 'l' is new gray list */
+ *l = NULL;
+ propagateall(g);
+}
+
+
static void convergeephemerons (global_State *g) {
int changed;
do {
@@ -399,11 +499,16 @@ static void convergeephemerons (global_State *g) {
} while (changed);
}
+/* }====================================================== */
/*
-** clear collected entries from weaktables
+** {======================================================
+** Sweep Functions
+** =======================================================
*/
+
+/* clear collected entries from weaktables */
static void cleartable (GCObject *l) {
while (l) {
Table *h = gco2t(l);
@@ -445,7 +550,6 @@ static void freeobj (lua_State *L, GCObject *o) {
}
-
#define sweepwholelist(L,p) sweeplist(L,p,MAX_LUMEM)
@@ -471,6 +575,8 @@ static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
}
+/* sweep list where all objects are alive (dead udata were removed
+ when separated from this list) */
static GCObject **unmarklist (global_State *g, GCObject **p, lu_mem count) {
for (; *p != NULL && count-- > 0; p = &gch(*p)->next) {
lua_assert(ttisuserdata(gch(*p)) && !isdead(g, *p));
@@ -479,6 +585,14 @@ static GCObject **unmarklist (global_State *g, GCObject **p, lu_mem count) {
return p;
}
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Finalization
+** =======================================================
+*/
static void checkSizes (lua_State *L) {
global_State *g = G(L);
@@ -541,6 +655,63 @@ void luaC_callGCTM (lua_State *L) {
}
+/* move 'dead' udata that need finalization to list 'tobefnz' */
+size_t luaC_separateudata (lua_State *L, int all) {
+ global_State *g = G(L);
+ size_t deadmem = 0;
+ GCObject **p = &g->tmudata;
+ GCObject *curr;
+ while ((curr = *p) != NULL) {
+ lua_assert(ttisuserdata(gch(curr)) && !isfinalized(gco2u(curr)));
+ lua_assert(testbit(gch(curr)->marked, SEPARATED));
+ if (all) makewhite(g, curr); /* if 'all', collect all objects */
+ if (!iswhite(curr)) /* not being collected? */
+ p = &gch(curr)->next; /* don't bother with it */
+ else {
+ l_setbit(gch(curr)->marked, FINALIZEDBIT); /* won't be finalized again */
+ reallymarkobject(g, curr); /* won't be collected now */
+ deadmem += sizeudata(gco2u(curr));
+ *p = gch(curr)->next; /* remove 'curr' from 'tmudata' list */
+ /* link 'curr' at the end of 'tobefnz' list */
+ if (g->tobefnz == NULL) /* list is empty? */
+ g->tobefnz = gch(curr)->next = curr; /* creates a circular list */
+ else {
+ gch(curr)->next = gch(g->tobefnz)->next;
+ gch(g->tobefnz)->next = curr;
+ g->tobefnz = curr;
+ }
+ }
+ }
+ return deadmem;
+}
+
+
+void luaC_checkfinalizer (lua_State *L, Udata *u) {
+ global_State *g = G(L);
+ if (testbit(u->uv.marked, SEPARATED) || /* userdata is already separated... */
+ isfinalized(&u->uv) || /* ... or is finalized... */
+ gfasttm(g, u->uv.metatable, TM_GC) == NULL) /* or has no finalization? */
+ return; /* nothing to be done */
+ else { /* move 'u' from root list to 'tmudata' list */
+ GCObject **p;
+ for (p = &g->rootgc; *p != obj2gco(u); p = &gch(*p)->next)
+ lua_assert(*p != NULL); /* 'u' must be in this list */
+ *p = u->uv.next; /* remove 'u' from root list */
+ u->uv.next = g->tmudata; /* link it in 'tmudata' list */
+ g->tmudata = obj2gco(u);
+ l_setbit(u->uv.marked, SEPARATED); /* mark it as such */
+ }
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** GC control
+** =======================================================
+*/
+
void luaC_freeall (lua_State *L) {
global_State *g = G(L);
int i;
@@ -557,61 +728,6 @@ void luaC_freeall (lua_State *L) {
}
-static void markmt (global_State *g) {
- int i;
- for (i=0; i<NUM_TAGS; i++)
- markobject(g, g->mt[i]);
-}
-
-
-static void markbeingfnz (global_State *g) {
- GCObject *u = g->tobefnz;
- if (u) {
- do {
- u = gch(u)->next;
- lua_assert(testbit(gch(u)->marked, SEPARATED));
- lua_assert(!iswhite(u)); /* must be marked, if left from previous GC */
- makewhite(g, u);
- reallymarkobject(g, u);
- } while (u != g->tobefnz);
- }
-}
-
-
-/* mark root set */
-static void markroot (lua_State *L) {
- global_State *g = G(L);
- g->gray = NULL;
- g->grayagain = NULL;
- g->weak = g->ephemeron = g->allweak = NULL;
- markobject(g, g->mainthread);
- /* make global table be traversed before main stack */
- markvalue(g, gt(g->mainthread));
- markvalue(g, registry(L));
- markmt(g);
- markbeingfnz(g); /* mark any finalizing userdata left from previous cycle */
- g->gcstate = GCSpropagate;
-}
-
-
-static void remarkupvals (global_State *g) {
- UpVal *uv;
- for (uv = g->uvhead.u.l.next; uv != &g->uvhead; uv = uv->u.l.next) {
- lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
- if (isgray(obj2gco(uv)))
- markvalue(g, uv->v);
- }
-}
-
-
-static void marklistofgrays (global_State *g, GCObject **l) {
- lua_assert(g->gray == NULL); /* no grays left */
- g->gray = *l; /* now 'l' is new gray list */
- *l = NULL;
- propagateall(g);
-}
-
-
static void atomic (lua_State *L) {
global_State *g = G(L);
size_t udsize; /* total size of userdata to be finalized */
@@ -626,8 +742,8 @@ static void atomic (lua_State *L) {
markobject(g, L); /* mark running thread */
markmt(g); /* mark basic metatables (again) */
propagateall(g);
- marklistofgrays(g, &g->ephemeron); /* remark ephemeron tables */
- marklistofgrays(g, &g->grayagain); /* remark gray again */
+ traverselistofgrays(g, &g->ephemeron); /* remark ephemeron tables */
+ traverselistofgrays(g, &g->grayagain); /* remark gray again */
convergeephemerons(g);
udsize = luaC_separateudata(L, 0); /* separate userdata to be finalized */
udsize += propagateall(g); /* remark, to propagate `preserveness' */
@@ -762,73 +878,6 @@ void luaC_fullgc (lua_State *L, int isemergency) {
setthreshold(g);
}
-
-void luaC_barrierf (lua_State *L, GCObject *o, GCObject *v) {
- global_State *g = G(L);
- lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
- lua_assert(g->gcstate != GCSfinalize && g->gcstate != GCSpause);
- lua_assert(ttype(gch(o)) != LUA_TTABLE);
- /* must keep invariant? */
- if (g->gcstate == GCSpropagate)
- reallymarkobject(g, v); /* restore invariant */
- else /* don't mind */
- makewhite(g, o); /* mark as white just to avoid other barriers */
-}
-
-
-void luaC_barrierback (lua_State *L, Table *t) {
- global_State *g = G(L);
- GCObject *o = obj2gco(t);
- lua_assert(isblack(o) && !isdead(g, o));
- lua_assert(g->gcstate != GCSfinalize && g->gcstate != GCSpause);
- black2gray(o); /* make table gray (again) */
- t->gclist = g->grayagain;
- g->grayagain = o;
-}
-
-
-void luaC_link (lua_State *L, GCObject *o, lu_byte tt) {
- global_State *g = G(L);
- gch(o)->marked = luaC_white(g);
- gch(o)->tt = tt;
- gch(o)->next = g->rootgc;
- g->rootgc = o;
-}
-
-
-void luaC_linkupval (lua_State *L, UpVal *uv) {
- global_State *g = G(L);
- GCObject *o = obj2gco(uv);
- gch(o)->next = g->rootgc; /* link upvalue into `rootgc' list */
- g->rootgc = o;
- if (isgray(o)) {
- if (g->gcstate == GCSpropagate) {
- gray2black(o); /* closed upvalues need barrier */
- luaC_barrier(L, uv, uv->v);
- }
- else { /* sweep phase: sweep it (turning it into white) */
- makewhite(g, o);
- lua_assert(g->gcstate != GCSfinalize && g->gcstate != GCSpause);
- }
- }
-}
-
-
-void luaC_checkfinalizer (lua_State *L, Udata *u) {
- global_State *g = G(L);
- if (testbit(u->uv.marked, SEPARATED) || /* userdata is already separated... */
- isfinalized(&u->uv) || /* ... or is finalized... */
- gfasttm(g, u->uv.metatable, TM_GC) == NULL) /* or has no finalization? */
- return; /* nothing to be done */
- else { /* move 'u' from root list to tobefnz list */
- GCObject **p;
- for (p = &g->rootgc; *p != obj2gco(u); p = &gch(*p)->next)
- lua_assert(*p != NULL); /* 'u' must be in this list */
- *p = u->uv.next; /* remove 'u' from root list */
- u->uv.next = g->tmudata; /* link it in tobefnz list */
- g->tmudata = obj2gco(u);
- l_setbit(u->uv.marked, SEPARATED); /* mark it as such */
- }
-}
+/* }====================================================== */
