r1258 - in branches/1.0: . bin/varnishd

[des at projects.linpro.no]

Author: des
Date: 2007-02-20 09:46:59 +0100 (Tue, 20 Feb 2007)
New Revision: 1258

Modified:
   branches/1.0/
   branches/1.0/bin/varnishd/cache_backend.c
   branches/1.0/bin/varnishd/cache_vrt.c
Log:
 r34134 at cat (orig r1238):  phk | 2007-01-22 14:24:42 +0100
 Expend a lock on keeping the backend statistics consistent.
 Rename the fields to make more sense
 
 



Property changes on: branches/1.0
___________________________________________________________________
Name: svk:merge
   - d4fa192b-c00b-0410-8231-f00ffab90ce4:/trunk/varnish-cache:1237
   + d4fa192b-c00b-0410-8231-f00ffab90ce4:/trunk/varnish-cache:1238

Modified: branches/1.0/bin/varnishd/cache_backend.c
===================================================================
--- branches/1.0/bin/varnishd/cache_backend.c	2007-02-20 08:46:57 UTC (rev 1257)
+++ branches/1.0/bin/varnishd/cache_backend.c	2007-02-20 08:46:59 UTC (rev 1258)
@@ -214,9 +214,12 @@
 
 /* Get a backend connection ------------------------------------------
  *
- * First locate the backend shadow, if necessary by creating one.
- * If there are free connections, use the first, otherwise build a
- * new connection.
+ * Try all cached backend connections for this backend, and use the
+ * first one that is looks like it is still connected.
+ * If that fails to get us a connection, create a new one, reusing a
+ * connection from the freelist, if possible.
+ *
+ * This function is slightly complicated by optimizations on vbemtx.
  */
 
 static struct vbe_conn *
@@ -225,20 +228,17 @@
 	struct vbe_conn *vc, *vc2;
 	struct pollfd pfd;
 	struct backend *bp;
+	int reuse = 0;
 
 	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
 	bp = sp->backend;
 	CHECK_OBJ_NOTNULL(bp, BACKEND_MAGIC);
+	vc2 = NULL;
 	while (1) {
-		/*
-		 * Try all connections on this backend until we find one
-		 * that works.  If that fails, grab a free connection
-		 * (if any) while we have the lock anyway.
-		 */
-		vc2 = NULL;
 		LOCK(&vbemtx);
 		vc = TAILQ_FIRST(&bp->connlist);
 		if (vc != NULL) {
+			assert(vc->backend == bp);
 			assert(vc->fd >= 0);
 			TAILQ_REMOVE(&bp->connlist, vc, list);
 		} else {
@@ -256,8 +256,10 @@
 		pfd.fd = vc->fd;
 		pfd.events = POLLIN;
 		pfd.revents = 0;
-		if (!poll(&pfd, 1, 0))
+		if (!poll(&pfd, 1, 0)) {
+			reuse = 1;
 			break;
+		}
 		VBE_ClosedFd(sp->wrk, vc, 0);
 	}
 
@@ -266,34 +268,33 @@
 			vc = vbe_new_conn();
 		else
 			vc = vc2;
-		AN(vc);
-		assert(vc->fd == -1);
-		AZ(vc->backend);
+		if (vc != NULL) {
+			assert(vc->fd == -1);
+			AZ(vc->backend);
+			vc->fd = vbe_connect(sp, bp);
+			if (vc->fd < 0) {
+				LOCK(&vbemtx);
+				TAILQ_INSERT_HEAD(&vbe_head, vc, list);
+				VSL_stats->backend_unused++;
+				UNLOCK(&vbemtx);
+				vc = NULL;
+			} else {
+				vc->backend = bp;
+			}
+		}
 	}
-
-	/* If not connected yet, do so */
-	if (vc->fd < 0) {
-		AZ(vc->backend);
-		vc->fd = vbe_connect(sp, bp);
-		LOCK(&vbemtx);
-		if (vc->fd < 0) {
-			vc->backend = NULL;
-			TAILQ_INSERT_HEAD(&vbe_head, vc, list);
-			VSL_stats->backend_unused++;
-			vc = NULL;
-		} else {
-			vc->backend = bp;
-		}
-		UNLOCK(&vbemtx);
+	LOCK(&vbemtx);
+	if (vc != NULL ) {
+		VSL_stats->backend_reuse += reuse;
+		VSL_stats->backend_conn++;
 	} else {
-		assert(vc->fd >= 0);
-		assert(vc->backend == bp);
+		VSL_stats->backend_fail++;
 	}
+	UNLOCK(&vbemtx);
 	if (vc != NULL ) {
+		WSL(sp->wrk, SLT_BackendXID, vc->fd, "%u", sp->xid);
 		assert(vc->fd >= 0);
-		VSL_stats->backend_conn++;
-		WSL(sp->wrk, SLT_BackendXID, vc->fd, "%u", sp->xid);
-		AN(vc->backend);
+		assert(vc->backend == bp);
 	}
 	return (vc);
 }
@@ -348,9 +349,9 @@
 	CHECK_OBJ_NOTNULL(vc, VBE_CONN_MAGIC);
 	assert(vc->fd >= 0);
 	AN(vc->backend);
-	VSL_stats->backend_recycle++;
 	WSL(w, SLT_BackendReuse, vc->fd, "%s", vc->backend->vcl_name);
 	LOCK(&vbemtx);
+	VSL_stats->backend_recycle++;
 	TAILQ_INSERT_HEAD(&vc->backend->connlist, vc, list);
 	UNLOCK(&vbemtx);
 }

Modified: branches/1.0/bin/varnishd/cache_vrt.c
===================================================================
--- branches/1.0/bin/varnishd/cache_vrt.c	2007-02-20 08:46:57 UTC (rev 1257)
+++ branches/1.0/bin/varnishd/cache_vrt.c	2007-02-20 08:46:59 UTC (rev 1258)
@@ -133,13 +133,14 @@
 VRT_free_backends(struct VCL_conf *cp)
 {
 
-	(void)cp;
+	(void)cp;	/* XXX */
 }
 
 void
 VRT_fini_backend(struct backend *be)
 {
-	(void)be;
+
+	(void)be;	/* XXX */
 }
 
 /*--------------------------------------------------------------------*/