Squid-2.2.STABLE2: Use estimated RTT for parent selection on timeouts
    Use estimated ICP rtt when selecting parents on ICP timeouts.

Index: squid/src/neighbors.c
diff -u squid/src/neighbors.c:1.1.1.31.6.4 squid/src/neighbors.c:1.1.1.31.6.7
--- squid/src/neighbors.c:1.1.1.31.6.4	Sat May  8 14:28:45 1999
+++ squid/src/neighbors.c	Sun May  9 07:50:43 1999
@@ -239,6 +239,34 @@
 }
 
 peer *
+getLowestRttParent(request_t * request)
+{
+    peer *p;
+    peer *p_rtt = NULL;
+    for (p = Config.peers; p; p = p->next) {
+	if (!p->stats.icp_last_reply_ok)
+	    continue;
+	if (!neighborUp(p))
+	    continue;
+	if (neighborType(p, request) != PEER_PARENT)
+	    continue;
+	if (!peerHTTPOkay(p, request))
+	    continue;
+	if (!peerWouldBePinged(p, request))
+	    continue;
+	if (!p_rtt || p->stats.rtt < p_rtt->stats.rtt)
+	    p_rtt = p;
+    }
+    if (p_rtt)
+	debug(15, 3) ("getLowestRttParent: returning %s RTT %d msec\n", p_rtt->host, p_rtt->stats.rtt);
+    else
+	debug(15, 4) ("getLowestRttParent: none found\n");
+    return p_rtt;
+}
+
+
+
+peer *
 getRoundRobinParent(request_t * request)
 {
     peer *p;
@@ -752,8 +780,20 @@
     if (opcode > ICP_END)
 	return;
     opcode_d = icp_opcode_str[opcode];
-    if (p)
+    if (p) {
 	neighborUpdateRtt(p, mem);
+	switch(opcode) {
+	case ICP_HIT:
+	case ICP_MISS:
+	case ICP_HIT_OBJ:
+	case ICP_DECHO:
+	    p->stats.icp_last_reply_ok = 1;
+	    break;
+	default:
+	    p->stats.icp_last_reply_ok = 0;
+	    break;
+	}
+    }
     /* Does the entry exist? */
     if (NULL == entry) {
 	debug(12, 3) ("neighborsUdpAck: Cache key '%s' not found\n",
Index: squid/src/peer_select.c
diff -u squid/src/peer_select.c:1.1.1.27.2.5 squid/src/peer_select.c:1.1.1.27.2.6
--- squid/src/peer_select.c:1.1.1.27.2.5	Fri May  7 16:19:25 1999
+++ squid/src/peer_select.c	Sat May  8 16:23:22 1999
@@ -392,6 +392,10 @@
     if (ps->closest_parent_miss.sin_addr.s_addr != any_addr.s_addr) {
 	p = whichPeer(&ps->closest_parent_miss);
 	code = CLOSEST_PARENT_MISS;
+    } else if (ps->ping.timedout) {
+	/* ICP pinging timedout, use estimated rtt's for selecing parent */
+	p = getLowestRttParent(request);
+	code = FIRST_PARENT_MISS;
     } else if (ps->first_parent_miss.sin_addr.s_addr != any_addr.s_addr) {
 	p = whichPeer(&ps->first_parent_miss);
 	code = FIRST_PARENT_MISS;
Index: squid/src/protos.h
diff -u squid/src/protos.h:1.1.1.39.4.2 squid/src/protos.h:1.1.1.39.4.3
--- squid/src/protos.h:1.1.1.39.4.2	Wed May  5 11:33:51 1999
+++ squid/src/protos.h	Sat May  8 16:23:22 1999
@@ -587,6 +587,7 @@
 
 extern peer *getFirstPeer(void);
 extern peer *getFirstUpParent(request_t *);
+extern peer *getLowestRttParent(request_t *);
 extern peer *getNextPeer(peer *);
 extern peer *getSingleParent(request_t *);
 extern int neighborsCount(request_t *);
Index: squid/src/structs.h
diff -u squid/src/structs.h:1.1.1.37.6.3 squid/src/structs.h:1.1.1.37.6.4
--- squid/src/structs.h:1.1.1.37.6.3	Wed May  5 11:33:52 1999
+++ squid/src/structs.h	Sun May  9 07:50:44 1999
@@ -1009,6 +1009,7 @@
 	time_t last_connect_failure;
 	time_t last_connect_probe;
 	int logged_state;	/* so we can print dead/revived msgs */
+	int icp_last_reply_ok;  /* did it accept a request? */
     } stats;
     struct {
 	int version;