Give sessions a backend connection instead of a backend and

have the directors provide that.

Entirely a no-op, apart from a bugfix that just would screw
you even more (than "totally") if socket(2) should ever fail.



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@3129 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache.h

@@ -354,7 +354,7 @@ struct sess {
 	VTAILQ_ENTRY(sess)	list;
 
 	struct director		*director;
-	struct backend		*backend;
+	struct vbe_conn		*vbe;
 	struct bereq		*bereq;
 	struct object		*obj;
 	struct objhead		*objhead;
@@ -397,9 +397,9 @@ extern int vca_pipes[2];
 
 /* cache_backend.c */
 
-struct vbe_conn *VBE_GetFd(struct sess *sp);
-void VBE_ClosedFd(struct worker *w, struct vbe_conn *vc);
-void VBE_RecycleFd(struct worker *w, struct vbe_conn *vc);
+void VBE_GetFd(struct sess *sp);
+void VBE_ClosedFd(struct sess *sp);
+void VBE_RecycleFd(struct sess *sp);
 struct bereq * VBE_new_bereq(void);
 void VBE_free_bereq(struct bereq *bereq);
 void VBE_AddHostHeader(const struct sess *sp);

bin/varnishd/cache_backend.c

@@ -66,9 +66,10 @@ VBE_AddHostHeader(const struct sess *sp)
 	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
 	CHECK_OBJ_NOTNULL(sp->bereq, BEREQ_MAGIC);
 	CHECK_OBJ_NOTNULL(sp->bereq->http, HTTP_MAGIC);
-	CHECK_OBJ_NOTNULL(sp->backend, BACKEND_MAGIC);
+	CHECK_OBJ_NOTNULL(sp->vbe, VBE_CONN_MAGIC);
+	CHECK_OBJ_NOTNULL(sp->vbe->backend, BACKEND_MAGIC);
 	http_PrintfHeader(sp->wrk, sp->fd, sp->bereq->http,
-	    "Host: %s", sp->backend->hosthdr);
+	    "Host: %s", sp->vbe->backend->hosthdr);
 }
 
 /*--------------------------------------------------------------------
@@ -81,24 +82,21 @@ VBE_AddHostHeader(const struct sess *sp)
  */
 
 static int
-VBE_TryConnect(const struct sess *sp, int pf, const struct sockaddr *sa, socklen_t salen)
+VBE_TryConnect(const struct sess *sp, int pf, const struct sockaddr *sa, socklen_t salen, const struct backend *bp)
 {
 	int s, i, tmo;
 	char abuf1[TCP_ADDRBUFSIZE], abuf2[TCP_ADDRBUFSIZE];
 	char pbuf1[TCP_PORTBUFSIZE], pbuf2[TCP_PORTBUFSIZE];
 
 	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
-	CHECK_OBJ_NOTNULL(sp->backend, BACKEND_MAGIC);
 
 	s = socket(pf, SOCK_STREAM, 0);
-	if (s < 0) {
-		LOCK(&sp->backend->mtx);
+	if (s < 0) 
 		return (s);
-	}
 
 	tmo = params->connect_timeout;
-	if (sp->backend->connect_timeout > 10e-3)
-		tmo = (int)(sp->backend->connect_timeout * 1000);
+	if (bp->connect_timeout > 10e-3)
+		tmo = (int)(bp->connect_timeout * 1000);
 
 	if (tmo > 0)
 		i = TCP_connect(s, sa, salen, tmo);
@@ -113,7 +111,7 @@ VBE_TryConnect(const struct sess *sp, int pf, const struct sockaddr *sa, socklen
 	TCP_myname(s, abuf1, sizeof abuf1, pbuf1, sizeof pbuf1);
 	TCP_name(sa, salen, abuf2, sizeof abuf2, pbuf2, sizeof pbuf2);
 	WSL(sp->wrk, SLT_BackendOpen, s, "%s %s %s %s %s",
-	    sp->backend->vcl_name, abuf1, pbuf1, abuf2, pbuf2);
+	    bp->vcl_name, abuf1, pbuf1, abuf2, pbuf2);
 
 	return (s);
 }
@@ -250,11 +248,11 @@ bes_conn_try(const struct sess *sp, struct backend *bp)
 	/* release lock during stuff that can take a long time */
 
 	if (params->prefer_ipv6 && bp->ipv6 != NULL)
-		s = VBE_TryConnect(sp, PF_INET6, bp->ipv6, bp->ipv6len);
+		s = VBE_TryConnect(sp, PF_INET6, bp->ipv6, bp->ipv6len, bp);
 	if (s == -1 && bp->ipv4 != NULL)
-		s = VBE_TryConnect(sp, PF_INET, bp->ipv4, bp->ipv4len);
+		s = VBE_TryConnect(sp, PF_INET, bp->ipv4, bp->ipv4len, bp);
 	if (s == -1 && !params->prefer_ipv6 && bp->ipv6 != NULL)
-		s = VBE_TryConnect(sp, PF_INET6, bp->ipv6, bp->ipv6len);
+		s = VBE_TryConnect(sp, PF_INET6, bp->ipv6, bp->ipv6len, bp);
 
 	if (s < 0) {
 		LOCK(&bp->mtx);
@@ -269,20 +267,15 @@ bes_conn_try(const struct sess *sp, struct backend *bp)
  * should contact.
  */
 
-struct vbe_conn *
+void
 VBE_GetFd(struct sess *sp)
 {
 
 	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
-
 	CHECK_OBJ_NOTNULL(sp->director, DIRECTOR_MAGIC);
 
-	if (sp->director->getfd != NULL)
-		return (sp->director->getfd(sp));
-
-	sp->backend = sp->director->choose(sp);
-	CHECK_OBJ_NOTNULL(sp->backend, BACKEND_MAGIC);
-	return (VBE_GetVbe(sp));
+	AN (sp->director->getfd);
+	sp->vbe = sp->director->getfd(sp);
 }
 
 /*--------------------------------------------------------------------
@@ -290,12 +283,11 @@ VBE_GetFd(struct sess *sp)
  */
 
 struct vbe_conn *
-VBE_GetVbe(const struct sess *sp)
+VBE_GetVbe(struct sess *sp, struct backend *bp)
 {
-	struct backend *bp;
 	struct vbe_conn *vc;
 
-	bp = sp->backend;
+	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
 	CHECK_OBJ_NOTNULL(bp, BACKEND_MAGIC);
 
 	/* first look for vbe_conn's we can recycle */
@@ -317,7 +309,8 @@ VBE_GetVbe(const struct sess *sp)
 			VSL_stats->backend_conn++;
 			return (vc);
 		}
-		VBE_ClosedFd(sp->wrk, vc);
+		sp->vbe = vc;
+		VBE_ClosedFd(sp);
 	}
 
 	vc = VBE_NewConn();
@@ -337,37 +330,41 @@ VBE_GetVbe(const struct sess *sp)
 /* Close a connection ------------------------------------------------*/
 
 void
-VBE_ClosedFd(struct worker *w, struct vbe_conn *vc)
+VBE_ClosedFd(struct sess *sp)
 {
-	struct backend *b;
+	struct backend *bp;
 
-	CHECK_OBJ_NOTNULL(vc, VBE_CONN_MAGIC);
-	CHECK_OBJ_NOTNULL(vc->backend, BACKEND_MAGIC);
-	b = vc->backend;
-	assert(vc->fd >= 0);
-	WSL(w, SLT_BackendClose, vc->fd, "%s", vc->backend->vcl_name);
-	TCP_close(&vc->fd);
-	VBE_DropRef(vc->backend);
-	vc->backend = NULL;
-	VBE_ReleaseConn(vc);
-	CHECK_OBJ_NOTNULL(b, BACKEND_MAGIC);
+	CHECK_OBJ_NOTNULL(sp->vbe, VBE_CONN_MAGIC);
+	CHECK_OBJ_NOTNULL(sp->vbe->backend, BACKEND_MAGIC);
+	assert(sp->vbe->fd >= 0);
+
+	bp = sp->vbe->backend;
+
+	WSL(sp->wrk, SLT_BackendClose, sp->vbe->fd, "%s", bp->vcl_name);
+	TCP_close(&sp->vbe->fd);
+	VBE_DropRef(bp);
+	sp->vbe->backend = NULL;
+	VBE_ReleaseConn(sp->vbe);
+	sp->vbe = NULL;
 }
 
 /* Recycle a connection ----------------------------------------------*/
 
 void
-VBE_RecycleFd(struct worker *w, struct vbe_conn *vc)
+VBE_RecycleFd(struct sess *sp)
 {
 	struct backend *bp;
 
-	CHECK_OBJ_NOTNULL(vc, VBE_CONN_MAGIC);
-	CHECK_OBJ_NOTNULL(vc->backend, BACKEND_MAGIC);
-	assert(vc->fd >= 0);
-	bp = vc->backend;
-	WSL(w, SLT_BackendReuse, vc->fd, "%s", vc->backend->vcl_name);
-	LOCK(&vc->backend->mtx);
+	CHECK_OBJ_NOTNULL(sp->vbe, VBE_CONN_MAGIC);
+	CHECK_OBJ_NOTNULL(sp->vbe->backend, BACKEND_MAGIC);
+	assert(sp->vbe->fd >= 0);
+
+	bp = sp->vbe->backend;
+
+	WSL(sp->wrk, SLT_BackendReuse, sp->vbe->fd, "%s", bp->vcl_name);
+	LOCK(&bp->mtx);
 	VSL_stats->backend_recycle++;
-	VTAILQ_INSERT_HEAD(&bp->connlist, vc, list);
-	VBE_DropRefLocked(vc->backend);
-	CHECK_OBJ_NOTNULL(bp, BACKEND_MAGIC);
+	VTAILQ_INSERT_HEAD(&bp->connlist, sp->vbe, list);
+	sp->vbe = NULL;
+	VBE_DropRefLocked(bp);
 }

bin/varnishd/cache_backend.h

@@ -78,14 +78,12 @@ struct vrt_backend_probe;
  */
 
 typedef struct vbe_conn *vdi_getfd_f(struct sess *sp);
-typedef struct backend *vdi_choose_f(struct sess *sp);
 typedef void vdi_fini_f(struct director *d);
 
 struct director {
 	unsigned		magic;
 #define DIRECTOR_MAGIC		0x3336351d
 	const char		*name;
-	vdi_choose_f		*choose;
 	vdi_getfd_f		*getfd;
 	vdi_fini_f		*fini;
 	void			*priv;
@@ -123,7 +121,7 @@ struct backend {
 
 /* cache_backend.c */
 void VBE_ReleaseConn(struct vbe_conn *vc);
-struct vbe_conn *VBE_GetVbe(const struct sess *sp);
+struct vbe_conn *VBE_GetVbe(struct sess *sp, struct backend *bp);
 
 /* cache_backend_cfg.c */
 extern MTX VBE_mtx;

bin/varnishd/cache_center.c

@@ -175,10 +175,6 @@ cnt_deliver(struct sess *sp)
 
 	sp->director = NULL;
 	sp->restarts = 0;
-	sp->backend = NULL;		/*
-					 * XXX: we may want to leave this
-					 * behind to hint directors ?
-					 */
 					
 	RES_WriteObj(sp);
 	HSH_Deref(sp->obj);
@@ -209,13 +205,10 @@ cnt_done(struct sess *sp)
 	CHECK_OBJ_ORNULL(sp->vcl, VCL_CONF_MAGIC);
 
 	AZ(sp->obj);
+	AZ(sp->vbe);
 	AZ(sp->bereq);
 	sp->director = NULL;
 	sp->restarts = 0;
-	sp->backend = NULL;		/*
-					 * XXX: we may want to leave this
-					 * behind to hint directors ?
-					 */
 					
 	if (sp->vcl != NULL && sp->esis == 0) {
 		if (sp->wrk->vcl != NULL)
@@ -389,7 +382,9 @@ cnt_fetch(struct sess *sp)
 
 	AN(sp->bereq);
 	AN(sp->director);
+	AZ(sp->vbe);
 	i = Fetch(sp);
+	AZ(sp->vbe);
 	AN(sp->director);
 
 	if (i) {

bin/varnishd/cache_dir_random.c

@@ -62,15 +62,15 @@ struct vdi_random {
 };
 
 
-/*lint -e{818} not const-able */
-static struct backend *
-vdi_random_choose(struct sess *sp)
+static struct vbe_conn *
+vdi_random_getfd(struct sess *sp)
 {
 	int i;
 	struct vdi_random *vs;
 	uint32_t r;
 	struct vdi_random_host *vh;
 
+	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
 	CHECK_OBJ_NOTNULL(sp->director, DIRECTOR_MAGIC);
 	CAST_OBJ_NOTNULL(vs, sp->director->priv, VDI_RANDOM_MAGIC);
 	r = random();
@@ -78,7 +78,7 @@ vdi_random_choose(struct sess *sp)
 
 	for (i = 0, vh = vs->hosts; i < vs->nhosts; vh++) 
 		if (r < vh->weight)
-			return (vh->backend);
+			return (VBE_GetVbe(sp, vh->backend));
 	assert(0 == __LINE__);
 	return (NULL);
 }
@@ -122,7 +122,7 @@ VRT_init_dir_random(struct cli *cli, struct director **bp, const struct vrt_dir_
 	vs->dir.magic = DIRECTOR_MAGIC;
 	vs->dir.priv = vs;
 	vs->dir.name = "random";
-	vs->dir.choose = vdi_random_choose;
+	vs->dir.getfd = vdi_random_getfd;
 	vs->dir.fini = vdi_random_fini;
 
 	s = 0;

bin/varnishd/cache_dir_round_robin.c

@@ -59,21 +59,20 @@ struct vdi_round_robin {
 	unsigned		next_host;
 };
 
-
-/*lint -e{818} not const-able */
-static struct backend *
-vdi_round_robin_choose(struct sess *sp)
+static struct vbe_conn *
+vdi_round_robin_getfd(struct sess *sp)
 {
 	struct vdi_round_robin *vs;
 	struct backend *backend;
 
+	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
 	CHECK_OBJ_NOTNULL(sp->director, DIRECTOR_MAGIC);
 	CAST_OBJ_NOTNULL(vs, sp->director->priv, VDI_ROUND_ROBIN_MAGIC);
 
 	backend = vs->hosts[ vs->next_host ].backend;
 	vs->next_host = (vs->next_host + 1) % vs->nhosts;
 
-	return (backend);
+	return (VBE_GetVbe(sp, backend));
 }
 
 /*lint -e{818} not const-able */
@@ -114,7 +113,7 @@ VRT_init_dir_round_robin(struct cli *cli, struct director **bp, const struct vrt
 	vs->dir.magic = DIRECTOR_MAGIC;
 	vs->dir.priv = vs;
 	vs->dir.name = "round_robin";
-	vs->dir.choose = vdi_round_robin_choose;
+	vs->dir.getfd = vdi_round_robin_getfd;
 	vs->dir.fini = vdi_round_robin_fini;
 
 	vh = vs->hosts;

bin/varnishd/cache_dir_simple.c

@@ -55,15 +55,15 @@ struct vdi_simple {
 	struct backend		*backend;
 };
 
-/*lint -e{818} not const-able */
-static struct backend *
-vdi_simple_choose(struct sess *sp)
+static struct vbe_conn *
+vdi_simple_getfd(struct sess *sp)
 {
 	struct vdi_simple *vs;
 
+	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
 	CHECK_OBJ_NOTNULL(sp->director, DIRECTOR_MAGIC);
 	CAST_OBJ_NOTNULL(vs, sp->director->priv, VDI_SIMPLE_MAGIC);
-	return (vs->backend);
+	return (VBE_GetVbe(sp, vs->backend));
 }
 
 /*lint -e{818} not const-able */
@@ -92,7 +92,7 @@ VRT_init_dir_simple(struct cli *cli, struct director **bp, const struct vrt_dir_
 	vs->dir.magic = DIRECTOR_MAGIC;
 	vs->dir.priv = vs;
 	vs->dir.name = "simple";
-	vs->dir.choose = vdi_simple_choose;
+	vs->dir.getfd = vdi_simple_getfd;
 	vs->dir.fini = vdi_simple_fini;
 
 	vs->backend = VBE_AddBackend(cli, t->host);

bin/varnishd/cache_fetch.c

@@ -332,9 +332,10 @@ Fetch(struct sess *sp)
 
 	/* Set up obj's workspace */
 	WS_Assert(sp->obj->ws_o);
-	vc = VBE_GetFd(sp);
-	if (vc == NULL)
+	VBE_GetFd(sp);
+	if (sp->vbe == NULL)
 		return (__LINE__);
+	vc = sp->vbe;
 
 	/*
 	 * Now that we know our backend, we can set a default Host:
@@ -351,12 +352,12 @@ Fetch(struct sess *sp)
 	/* Deal with any message-body the request might have */
 	i = FetchReqBody(sp);
 	if (i > 0) {
-		VBE_ClosedFd(sp->wrk, vc);
+		VBE_ClosedFd(sp);
 		return (__LINE__);
 	}
 
 	if (WRK_Flush(w)) {
-		VBE_ClosedFd(sp->wrk, vc);
+		VBE_ClosedFd(sp);
 		/* XXX: other cleanup ? */
 		return (__LINE__);
 	}
@@ -370,13 +371,13 @@ Fetch(struct sess *sp)
 	while (i == 0);
 
 	if (i < 0) {
-		VBE_ClosedFd(sp->wrk, vc);
+		VBE_ClosedFd(sp);
 		/* XXX: other cleanup ? */
 		return (__LINE__);
 	}
 
 	if (http_DissectResponse(sp->wrk, htc, hp)) {
-		VBE_ClosedFd(sp->wrk, vc);
+		VBE_ClosedFd(sp);
 		/* XXX: other cleanup ? */
 		return (__LINE__);
 	}
@@ -408,7 +409,7 @@ Fetch(struct sess *sp)
 	} else if (http_GetHdr(hp, H_Transfer_Encoding, &b)) {
 		/* XXX: AUGH! */
 		WSL(sp->wrk, SLT_Debug, vc->fd, "Invalid Transfer-Encoding");
-		VBE_ClosedFd(sp->wrk, vc);
+		VBE_ClosedFd(sp);
 		return (__LINE__);
 	} else {
 		switch (http_GetStatus(hp)) {
@@ -428,7 +429,7 @@ Fetch(struct sess *sp)
 			VTAILQ_REMOVE(&sp->obj->store, st, list);
 			STV_free(st);
 		}
-		VBE_ClosedFd(sp->wrk, vc);
+		VBE_ClosedFd(sp);
 		sp->obj->len = 0;
 		return (__LINE__);
 	}
@@ -451,9 +452,9 @@ Fetch(struct sess *sp)
 		cls = 1;
 
 	if (cls)
-		VBE_ClosedFd(sp->wrk, vc);
+		VBE_ClosedFd(sp);
 	else
-		VBE_RecycleFd(sp->wrk, vc);
+		VBE_RecycleFd(sp);
 
 	return (0);
 }

bin/varnishd/cache_panic.c

@@ -83,10 +83,14 @@ pan_ws(const struct ws *ws, int indent)
 /*--------------------------------------------------------------------*/
 
 static void
-pan_backend(const struct backend *be)
+pan_vbe(const struct vbe_conn *vbe)
 {
 
-	vsb_printf(vsp, "  backend = %p {\n", be);
+	struct backend *be;
+
+	be = vbe->backend;
+
+	vsb_printf(vsp, "  backend = %p fd = %d {\n", be, vbe->fd);
 	vsb_printf(vsp, "    vcl_name = \"%s\",\n", be->vcl_name);
 	vsb_printf(vsp, "  },\n");
 }
@@ -242,8 +246,8 @@ pan_sess(const struct sess *sp)
 	if (VALID_OBJ(sp->vcl, VCL_CONF_MAGIC))
 		pan_vcl(sp->vcl);
 
-	if (VALID_OBJ(sp->backend, BACKEND_MAGIC))
-		pan_backend(sp->backend);
+	if (VALID_OBJ(sp->vbe, BACKEND_MAGIC))
+		pan_vbe(sp->vbe);
 
 	if (VALID_OBJ(sp->obj, OBJECT_MAGIC))
 		pan_object(sp->obj);

bin/varnishd/cache_pipe.c

@@ -77,9 +77,10 @@ PipeSession(struct sess *sp)
 	bereq = sp->bereq;
 	sp->bereq = NULL;
 
-	vc = VBE_GetFd(sp);
-	if (vc == NULL)
+	VBE_GetFd(sp);
+	if (sp->vbe == NULL)
 		return;
+	vc = sp->vbe;
 	TCP_blocking(vc->fd);
 
 	WRK_Reset(w, &vc->fd);
@@ -91,7 +92,7 @@ PipeSession(struct sess *sp)
 
 	if (WRK_Flush(w)) {
 		vca_close_session(sp, "pipe");
-		VBE_ClosedFd(sp->wrk, vc);
+		VBE_ClosedFd(sp);
 		return;
 	}
 
@@ -134,5 +135,5 @@ PipeSession(struct sess *sp)
 		(void)shutdown(vc->fd, SHUT_WR);
 	}
 	vca_close_session(sp, "pipe");
-	VBE_ClosedFd(sp->wrk, vc);
+	VBE_ClosedFd(sp);
 }