From fd4c68d75b5e06868c8dfd1b1078694460a1ad41 Mon Sep 17 00:00:00 2001
From: Frederic Robra
Date: Wed, 17 Jul 2019 17:13:17 +0200
Subject: added some comments and macros

---
 src/kernel/net.c | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

(limited to 'src/kernel/net.c')

diff --git a/src/kernel/net.c b/src/kernel/net.c
index d493994..2edb422 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -548,7 +548,7 @@ static struct dnbd3_server *dnbd3_find_best_alt_server(struct dnbd3_device *dev)
 		}
 	}
 
-	best_rtt = current_best_rtt * 10; // TODO add DEFINE to control this
+	best_rtt = RTT_THRESOULD_LIMIT(current_best_rtt);
 	debug_dev(dev, "best connected rtt is %llu, searching for rtt better than %llu", current_best_rtt, best_rtt);
 
 	for (i = 0; i < NUMBER_SERVERS; i++) {
@@ -581,7 +581,7 @@ static bool dnbd3_better_rtt(struct dnbd3_server *new_server, struct dnbd3_serve
 	uint64_t new_rtt = (new_server->rtts[0] + new_server->rtts[1] + new_server->rtts[2] + new_server->rtts[3]) / 4;
 	uint64_t existing_rtt = (existing_server->rtts[0] + existing_server->rtts[1] + existing_server->rtts[2] + existing_server->rtts[3]) / 4;
 
-	if (new_rtt < ((existing_rtt * 2)/3)) { //TODO add macro to control this
+	if (new_rtt < RTT_THRESHOLD_FACTOR(existing_rtt)) {
 		return true;
 	}
 	return false;
@@ -590,6 +590,8 @@ static bool dnbd3_better_rtt(struct dnbd3_server *new_server, struct dnbd3_serve
 static void dnbd3_adjust_connections(struct dnbd3_device *dev) {
 	int i;
 	int sock_alive = 0;
+	uint64_t rtt;
+	uint64_t best_rtt = RTT_UNREACHABLE;
 	struct dnbd3_server *server, *existing_server;
 
 	// connect empty sockets
@@ -627,6 +629,28 @@ static void dnbd3_adjust_connections(struct dnbd3_device *dev) {
 		}
 	}
 
+	// remove a socket if it is much slower than the others
+	if (sock_alive > 1) {
+		for (i = 0; i < NUMBER_CONNECTIONS; i++) {
+			if (dnbd3_is_sock_alive(dev->socks[i])) {
+				rtt = (dev->socks[i].server->rtts[0] + dev->socks[i].server->rtts[1] + dev->socks[i].server->rtts[2] + dev->socks[i].server->rtts[3]) / 4;
+				if (rtt <= best_rtt) {
+					best_rtt = rtt;
+				}
+			}
+		}
+		for (i = 0; i < NUMBER_CONNECTIONS; i++) {
+			if (dnbd3_is_sock_alive(dev->socks[i])) {
+				rtt = (dev->socks[i].server->rtts[0] + dev->socks[i].server->rtts[1] + dev->socks[i].server->rtts[2] + dev->socks[i].server->rtts[3]) / 4;
+				if (rtt > RTT_THRESOULD_LIMIT(best_rtt)) {
+					info_sock(&dev->socks[i], "removing connection with rtt %llu", rtt);
+					dnbd3_socket_disconnect(dev, NULL, &dev->socks[i]);
+					sock_alive--;
+				}
+			}
+		}
+	}
+
 	debug_dev(dev, "connected to %d/%d sockets", sock_alive, NUMBER_CONNECTIONS);
 }
 
@@ -972,6 +996,9 @@ error:
 	return result;
 }
 
+/**
+ * connect a dnbd3 device to a server
+ */
 static int dnbd3_socket_connect(struct dnbd3_device *dev, struct dnbd3_server *server)
 {
 	int i;
-- 
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