Abstract some "manage list of backends" code which most of the directors

will need.

lib/libvmod_directors/Makefile.am

@@ -14,6 +14,7 @@ noinst_LTLIBRARIES = libvmod_directors.la
 libvmod_directors_la_LDFLAGS = $(AM_LDFLAGS) -module -export-dynamic -avoid-version -shared -rpath /nowhere
 
 libvmod_directors_la_SOURCES = \
+	vdir.c \
 	round_robin.c
 
 nodist_libvmod_directors_la_SOURCES = \

lib/libvmod_directors/round_robin.c

@@ -36,61 +36,45 @@
 #include "vrt.h"
 #include "vcc_if.h"
 
-struct rr_entry {
-	unsigned				magic;
-#define RR_ENTRY_MAGIC				0xa80970cf
-	VTAILQ_ENTRY(rr_entry)			list;
-	VCL_BACKEND				be;
-};
+#include "vdir.h"
 
 struct vmod_directors_round_robin {
 	unsigned				magic;
-#define VMOD_DEBUG_RR_MAGIC			0x99f4b726
-	VTAILQ_HEAD(, rr_entry)			listhead;
-	int					nbe;
-	pthread_mutex_t				mtx;
-	struct director				*dir;
+#define VMOD_DIRECTORS_ROUND_ROBIN_MAGIC	0xa80970cf
+	struct vdir				*vd;
+	unsigned				nxt;
 };
 
-static unsigned
+static unsigned __match_proto__(vdi_healthy)
 vmod_rr_healthy(const struct director *dir, const struct req *req)
 {
-	struct rr_entry *ep;
 	struct vmod_directors_round_robin *rr;
-	unsigned retval = 0;
 
-	CAST_OBJ_NOTNULL(rr, dir->priv, VMOD_DEBUG_RR_MAGIC);
-	AZ(pthread_mutex_lock(&rr->mtx));
-	VTAILQ_FOREACH(ep, &rr->listhead, list) {
-		if (ep->be->healthy(ep->be, req)) {
-			retval = 1;
-			break;
-		}
-	}
-	AZ(pthread_mutex_unlock(&rr->mtx));
-	return (retval);
+	CAST_OBJ_NOTNULL(rr, dir->priv, VMOD_DIRECTORS_ROUND_ROBIN_MAGIC);
+	return (vdir_any_healthy(rr->vd, req));
 }
 
-static struct vbc *
+static struct vbc * __match_proto__(vdi_getfd_f)
 vmod_rr_getfd(const struct director *dir, struct req *req)
 {
-	struct rr_entry *ep = NULL;
 	struct vmod_directors_round_robin *rr;
-	int i;
-
-	CAST_OBJ_NOTNULL(rr, dir->priv, VMOD_DEBUG_RR_MAGIC);
-	AZ(pthread_mutex_lock(&rr->mtx));
-	for (i = 0; i < rr->nbe; i++) {
-		ep = VTAILQ_FIRST(&rr->listhead);
-		VTAILQ_REMOVE(&rr->listhead, ep, list);
-		VTAILQ_INSERT_TAIL(&rr->listhead, ep, list);
-		if (ep->be->healthy(ep->be, req))
+	unsigned u;
+	VCL_BACKEND be = NULL;
+
+	CAST_OBJ_NOTNULL(rr, dir->priv, VMOD_DIRECTORS_ROUND_ROBIN_MAGIC);
+	vdir_lock(rr->vd);
+	for (u = 0; u < rr->vd->n_backend; u++) {
+		rr->nxt %= rr->vd->n_backend;
+		be = rr->vd->backend[rr->nxt];
+		rr->nxt++;
+		CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);
+		if (be->healthy(be, req))
 			break;
 	}
-	AZ(pthread_mutex_unlock(&rr->mtx));
-	if (i == rr->nbe || ep == NULL)
+	vdir_unlock(rr->vd);
+	if (u == rr->vd->n_backend || be == NULL)
 		return (NULL);
-	return (ep->be->getfd(ep->be, req));
+	return (be->getfd(be, req));
 }
 
 VCL_VOID
@@ -99,65 +83,42 @@ vmod_round_robin__init(struct req *req, struct vmod_directors_round_robin **rrp,
 {
 	struct vmod_directors_round_robin *rr;
 
-	(void)req;
-
+	AZ(req);
 	AN(rrp);
 	AZ(*rrp);
-	ALLOC_OBJ(rr, VMOD_DEBUG_RR_MAGIC);
+	ALLOC_OBJ(rr, VMOD_DIRECTORS_ROUND_ROBIN_MAGIC);
 	AN(rr);
 	*rrp = rr;
-	AZ(pthread_mutex_init(&rr->mtx, NULL));
-	VTAILQ_INIT(&rr->listhead);
-	ALLOC_OBJ(rr->dir, DIRECTOR_MAGIC);
-	AN(rr->dir);
-	REPLACE(rr->dir->vcl_name, vcl_name);
-	rr->dir->priv = rr;
-	rr->dir->healthy = vmod_rr_healthy;
-	rr->dir->getfd = vmod_rr_getfd;
+	vdir_new(&rr->vd, vcl_name, vmod_rr_healthy, vmod_rr_getfd, rr);
 }
 
 VCL_VOID
 vmod_round_robin__fini(struct req *req, struct vmod_directors_round_robin **rrp)
 {
 	struct vmod_directors_round_robin *rr;
-	struct rr_entry *ep;
-
-	(void)req;
 
+	AZ(req);
 	rr = *rrp;
 	*rrp = NULL;
-	CHECK_OBJ_NOTNULL(rr, VMOD_DEBUG_RR_MAGIC);
-
-	AZ(pthread_mutex_destroy(&rr->mtx));
-	while (!VTAILQ_EMPTY(&rr->listhead)) {
-		ep = VTAILQ_FIRST(&rr->listhead);
-		VTAILQ_REMOVE(&rr->listhead, ep, list);
-		FREE_OBJ(ep);
-	}
-	free(rr->dir->vcl_name);
-	FREE_OBJ(rr->dir);
+	CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_ROUND_ROBIN_MAGIC);
+	vdir_delete(&rr->vd);
 	FREE_OBJ(rr);
 }
 
 VCL_VOID
-vmod_round_robin_add_backend(struct req *req, struct vmod_directors_round_robin * rr,
-    VCL_BACKEND be)
+vmod_round_robin_add_backend(struct req *req,
+    struct vmod_directors_round_robin *rr, VCL_BACKEND be)
 {
-	struct rr_entry *ep;
-	(void)req;
 
-	ALLOC_OBJ(ep, RR_ENTRY_MAGIC);
-	AN(ep);
-	ep->be = be;
-	AZ(pthread_mutex_lock(&rr->mtx));
-	VTAILQ_INSERT_TAIL(&rr->listhead, ep, list);
-	rr->nbe++;
-	AZ(pthread_mutex_unlock(&rr->mtx));
+	(void)req;
+	CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_ROUND_ROBIN_MAGIC);
+	vdir_add_backend(rr->vd, be, 0.0);
 }
 
 VCL_BACKEND __match_proto__()
 vmod_round_robin_backend(struct req *req, struct vmod_directors_round_robin *rr)
 {
 	(void)req;
-	return (rr->dir);
+	CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_ROUND_ROBIN_MAGIC);
+	return (rr->vd->dir);
 }

lib/libvmod_directors/vdir.c

+/*-
+ * Copyright (c) 2013 Varnish Software AS
+ * All rights reserved.
+ *
+ * Author: Poul-Henning Kamp <phk@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+
+#include "cache/cache.h"
+#include "cache/cache_backend.h"
+
+#include "vrt.h"
+
+#include "vdir.h"
+
+static void
+vdir_expand(struct vdir *vd, unsigned n)
+{
+	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
+
+	vd->backend = realloc(vd->backend, n * sizeof *vd->backend);
+	AN(vd->backend);
+	vd->weight = realloc(vd->weight, n * sizeof *vd->weight);
+	AN(vd->weight);
+	vd->l_backend = n;
+}
+
+void
+vdir_new(struct vdir **vdp, const char *vcl_name, vdi_healthy *healthy,
+    vdi_getfd_f *getfd, void *priv)
+{
+	struct vdir *vd;
+
+	AN(vcl_name);
+	AN(vdp);
+	AZ(*vdp);
+	ALLOC_OBJ(vd, VDIR_MAGIC);
+	AN(vd);
+	*vdp = vd;
+	AZ(pthread_mutex_init(&vd->mtx, NULL));
+
+	ALLOC_OBJ(vd->dir, DIRECTOR_MAGIC);
+	AN(vd->dir);
+	REPLACE(vd->dir->vcl_name, vcl_name);
+	vd->dir->priv = priv;
+	vd->dir->healthy = healthy;
+	vd->dir->getfd = getfd;
+}
+
+void
+vdir_delete(struct vdir **vdp)
+{
+	struct vdir *vd;
+
+	AN(vdp);
+	vd = *vdp;
+	*vdp = NULL;
+
+	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
+
+	free(vd->backend);
+	free(vd->weight);
+	AZ(pthread_mutex_destroy(&vd->mtx));
+	FREE_OBJ(vd->dir);
+	FREE_OBJ(vd);
+}
+
+void
+vdir_lock(struct vdir *vd)
+{
+	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
+	AZ(pthread_mutex_lock(&vd->mtx));
+}
+
+void
+vdir_unlock(struct vdir *vd)
+{
+	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
+	AZ(pthread_mutex_unlock(&vd->mtx));
+}
+
+
+unsigned
+vdir_add_backend(struct vdir *vd, VCL_BACKEND be, double weight)
+{
+	unsigned u;
+
+	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
+	AN(be);
+	vdir_lock(vd);
+	if (vd->n_backend >= vd->l_backend)
+		vdir_expand(vd, vd->l_backend + 16);
+	assert(vd->n_backend < vd->l_backend);
+	u = vd->n_backend++;
+	vd->backend[u] = be;
+	vd->weight[u] = weight;
+	vdir_unlock(vd);
+	return (u);
+}
+
+unsigned
+vdir_any_healthy(struct vdir *vd, const struct req *req)
+{
+	unsigned retval = 0;
+	VCL_BACKEND be;
+	unsigned u;
+
+	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
+	vdir_lock(vd);
+	for (u = 0; u < vd->n_backend; u++) {
+		be = vd->backend[u];
+		CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);
+		if (be->healthy(be, req)) {
+			retval = 1;
+			break;
+		}
+	}
+	vdir_unlock(vd);
+	return (retval);
+}

lib/libvmod_directors/vdir.h

+/*-
+ * Copyright (c) 2013 Varnish Software AS
+ * All rights reserved.
+ *
+ * Author: Poul-Henning Kamp <phk@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+struct vdir {
+	unsigned				magic;
+#define VDIR_MAGIC				0x99f4b726
+	pthread_mutex_t				mtx;
+	unsigned				n_backend;
+	unsigned				l_backend;
+	VCL_BACKEND				*backend;
+	double					*weight;
+	struct director				*dir;
+};
+
+void vdir_new(struct vdir **vdp, const char *vcl_name, vdi_healthy *healthy,
+    vdi_getfd_f *getfd, void *priv);
+void vdir_delete(struct vdir **vdp);
+void vdir_lock(struct vdir *vd);
+void vdir_unlock(struct vdir *vd);
+unsigned vdir_add_backend(struct vdir *vd, VCL_BACKEND be, double weight);
+unsigned vdir_any_healthy(struct vdir *vd, const struct req *);