Clean up the LRU stuff a bit, wrap the senteniel with the list head etc.

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@4213 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache.h

@@ -296,6 +296,15 @@ struct objcore {
 	struct ban		*ban;
 };
 
+/*--------------------------------------------------------------------*/
+
+struct lru {
+	unsigned		magic;
+#define LRU_MAGIC		0x3fec7bb0
+	VLIST_HEAD(,objcore)	lru_head;
+	struct objcore		senteniel;
+};
+
 /* Object structure --------------------------------------------------*/
 
 struct object {
@@ -488,11 +497,11 @@ extern pthread_t cli_thread;
 
 /* cache_expiry.c */
 void EXP_Insert(struct object *o);
-void EXP_Inject(struct objcore *oc, struct objcore *lrut, double ttl);
+void EXP_Inject(struct objcore *oc, struct lru *lru, double ttl);
 void EXP_Init(void);
 void EXP_Rearm(const struct object *o);
 int EXP_Touch(const struct object *o);
-int EXP_NukeOne(struct sess *sp, const struct objcore_head *lru);
+int EXP_NukeOne(struct sess *sp, const struct lru *lru);
 
 /* cache_fetch.c */
 int FetchHdr(struct sess *sp);

bin/varnishd/cache_expire.c

@@ -97,18 +97,18 @@ update_object_when(const struct object *o)
  */
 
 void
-EXP_Inject(struct objcore *oc, struct objcore *lrut, double ttl)
+EXP_Inject(struct objcore *oc, struct lru *lru, double ttl)
 {
 
 	CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
-	CHECK_OBJ_NOTNULL(lrut, OBJCORE_MAGIC);
+	CHECK_OBJ_NOTNULL(lru, LRU_MAGIC);
 
 	Lck_Lock(&exp_mtx);
 	assert(oc->timer_idx == BINHEAP_NOIDX);
 	oc->timer_when = ttl;
 	binheap_insert(exp_heap, oc);
 	assert(oc->timer_idx != BINHEAP_NOIDX);
-	VLIST_INSERT_BEFORE(lrut, oc, lru_list);
+	VLIST_INSERT_BEFORE(&lru->senteniel, oc, lru_list);
 	oc->flags |= OC_F_ONLRU;
 	Lck_Unlock(&exp_mtx);
 }
@@ -123,7 +123,8 @@ EXP_Inject(struct objcore *oc, struct objcore *lrut, double ttl)
 void
 EXP_Insert(struct object *o)
 {
-	struct objcore *oc, *lrut;
+	struct objcore *oc;
+	struct lru *lru;
 
 	CHECK_OBJ_NOTNULL(o, OBJECT_MAGIC);
 	CHECK_OBJ_NOTNULL(o->objcore, OBJCORE_MAGIC);
@@ -134,15 +135,15 @@ EXP_Insert(struct object *o)
 
 	assert(o->entered != 0 && !isnan(o->entered));
 	o->last_lru = o->entered;
-	lrut = STV_lru(o->objstore);
 	Lck_Lock(&exp_mtx);
 	assert(oc->timer_idx == BINHEAP_NOIDX);
 	(void)update_object_when(o);
 	binheap_insert(exp_heap, oc);
 	assert(oc->timer_idx != BINHEAP_NOIDX);
 	if (o->objstore != NULL) {
-		CHECK_OBJ_NOTNULL(lrut, OBJCORE_MAGIC);
-		VLIST_INSERT_BEFORE(lrut, oc, lru_list);
+		lru = STV_lru(o->objstore);
+		CHECK_OBJ_NOTNULL(lru, LRU_MAGIC);
+		VLIST_INSERT_BEFORE(&lru->senteniel, oc, lru_list);
 		oc->flags |= OC_F_ONLRU;
 	}
 	Lck_Unlock(&exp_mtx);
@@ -163,7 +164,8 @@ int
 EXP_Touch(const struct object *o)
 {
 	int retval = 0;
-	struct objcore *oc, *lrut;
+	struct objcore *oc;
+	struct lru *lru;
 
 	CHECK_OBJ_NOTNULL(o, OBJECT_MAGIC);
 	oc = o->objcore;
@@ -174,13 +176,13 @@ EXP_Touch(const struct object *o)
 	CHECK_OBJ_NOTNULL(oc->objhead, OBJHEAD_MAGIC);
 	if (o->objstore == NULL)	/* XXX ?? */
 		return (retval);
-	lrut = STV_lru(o->objstore);
-	CHECK_OBJ_NOTNULL(lrut, OBJCORE_MAGIC);
+	lru = STV_lru(o->objstore);
+	CHECK_OBJ_NOTNULL(lru, LRU_MAGIC);
 	if (Lck_Trylock(&exp_mtx))
 		return (retval);
 	if (oc->flags & OC_F_ONLRU) {	/* XXX ?? */
 		VLIST_REMOVE(oc, lru_list);
-		VLIST_INSERT_BEFORE(lrut, oc, lru_list);
+		VLIST_INSERT_BEFORE(&lru->senteniel, oc, lru_list);
 		VSL_stats->n_lru_moved++;
 		retval = 1;
 	}
@@ -303,7 +305,7 @@ exp_timer(struct sess *sp, void *priv)
  */
 
 int
-EXP_NukeOne(struct sess *sp, const struct objcore_head *lru)
+EXP_NukeOne(struct sess *sp, const struct lru *lru)
 {
 	struct objcore *oc;
 
@@ -318,7 +320,12 @@ EXP_NukeOne(struct sess *sp, const struct objcore_head *lru)
 	 *
 	 */
 	Lck_Lock(&exp_mtx);
-	VLIST_FOREACH(oc, lru, lru_list) {
+	VLIST_FOREACH(oc, &lru->lru_head, lru_list) {
+		if (oc == &lru->senteniel) {
+			AZ(VLIST_NEXT(oc, lru_list));
+			oc = NULL;
+			break;
+		}
 		CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
 		if (oc->timer_idx == BINHEAP_NOIDX)	/* exp_timer has it */
 			continue;

bin/varnishd/common.h

@@ -64,8 +64,3 @@ struct choice {
 	const char      *name;
 	void            *ptr;
 };
-
-/* Sort of hack-ish... */
-struct objcore;
-VLIST_HEAD(objcore_head, objcore);
-

bin/varnishd/stevedore.c

@@ -43,6 +43,18 @@ static VTAILQ_HEAD(, stevedore)	stevedores =
 
 static const struct stevedore * volatile stv_next;
 
+static struct lru *
+LRU_Alloc(void)
+{
+	struct lru *l;
+
+	ALLOC_OBJ(l, LRU_MAGIC);
+	AN(l);
+	VLIST_INIT(&l->lru_head);
+	VLIST_INSERT_HEAD(&l->lru_head, &l->senteniel, lru_list);
+	return (l);
+}
+
 struct storage *
 STV_alloc(struct sess *sp, size_t size)
 {
@@ -81,7 +93,7 @@ STV_alloc(struct sess *sp, size_t size)
 			break;
 
 		/* no luck; try to free some space and keep trying */
-		if (EXP_NukeOne(sp, &stv->lru) == -1)
+		if (EXP_NukeOne(sp, stv->lru) == -1)
 			break;
 
 		/* Enough is enough: try another if we have one */
@@ -124,9 +136,7 @@ STV_add(const struct stevedore *stv2, int ac, char * const *av)
 	*stv = *stv2;
 	AN(stv->name);
 	AN(stv->alloc);
-	ALLOC_OBJ(stv->lru_tail, OBJCORE_MAGIC);
-	VLIST_INIT(&stv->lru);
-	VLIST_INSERT_HEAD(&stv->lru, stv->lru_tail, lru_list);
+	stv->lru = LRU_Alloc();
 
 	if (stv->init != NULL)
 		stv->init(stv, ac, av);
@@ -161,12 +171,12 @@ STV_close(void)
 	}
 }
 
-struct objcore *
-STV_lru(struct storage *st)
+struct lru *
+STV_lru(const struct storage *st)
 {
 	CHECK_OBJ_NOTNULL(st, STORAGE_MAGIC);
 
-	return (st->stevedore->lru_tail);
+	return (st->stevedore->lru);
 }
 
 const struct choice STV_choice[] = {

bin/varnishd/stevedore.h

@@ -42,6 +42,7 @@ typedef void storage_free_f(struct storage *);
 typedef void storage_object_f(const struct sess *sp);
 typedef void storage_close_f(const struct stevedore *);
 
+
 struct stevedore {
 	unsigned		magic;
 #define STEVEDORE_MAGIC		0x4baf43db
@@ -54,8 +55,7 @@ struct stevedore {
 	storage_object_f	*object;
 	storage_close_f		*close;
 
-	struct objcore_head	lru;
-	struct objcore		*lru_tail;
+	struct lru		*lru;
 
 	/* private fields */
 	void			*priv;
@@ -69,7 +69,7 @@ void STV_free(struct storage *st);
 void STV_add(const struct stevedore *stv, int ac, char * const *av);
 void STV_open(void);
 void STV_close(void);
-struct objcore *STV_lru(struct storage *st);
+struct lru *STV_lru(const struct storage *st);
 
 
 int STV_GetFile(const char *fn, int *fdp, const char **fnp, const char *ctx);

bin/varnishd/storage_persistent.c

@@ -837,7 +837,7 @@ smp_load_seg(struct sess *sp, const struct smp_sc *sc, struct smp_seg *sg)
 		memcpy(sp->wrk->nobjhead->digest, so->hash, SHA256_LEN);
 		(void)HSH_Insert(sp);
 		AZ(sp->wrk->nobjcore);
-		EXP_Inject(oc, sc->parent->lru_tail, so->ttl);
+		EXP_Inject(oc, sc->parent->lru, so->ttl);
 		sg->nalloc++;
 	}
 	WRK_SumStat(sp->wrk);