[Spice-devel] [PATCH spice-server 2/2] red_channel: on migration target, start sending ping messages only after the client's migration has completed

[Yonit Halperin]

The connection to the target server is established before migration
starts. However, the client reads and replies to messages from the server only after
migration completes. Thus, we better not send ping msgs from the target
before migration completes (because the observed roundtrip duration will
be bigger than the real one).
---
 server/red_channel.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/server/red_channel.c b/server/red_channel.c
index 4e03d64..9d71543 100644
--- a/server/red_channel.c
+++ b/server/red_channel.c
@@ -805,7 +805,9 @@ RedChannelClient *red_channel_client_create(int size, RedChannel *channel, RedCl
     if (monitor_latency) {
         rcc->latency_monitor.timer = channel->core->timer_add(
             red_channel_client_ping_timer, rcc);
-        red_channel_client_start_ping_timer(rcc, PING_TEST_IDLE_NET_TIMEOUT_MS);
+        if (!client->during_target_migrate) {
+            red_channel_client_start_ping_timer(rcc, PING_TEST_IDLE_NET_TIMEOUT_MS);
+        }
         rcc->latency_monitor.roundtrip = -1;
     }
 
@@ -832,6 +834,9 @@ static void red_channel_client_seamless_migration_done(RedChannelClient *rcc)
         /* migration completion might have been triggered from a different thread
          * than the main thread */
         main_dispatcher_seamless_migrate_dst_complete(rcc->client);
+        if (rcc->latency_monitor.timer) {
+            red_channel_client_start_ping_timer(rcc, PING_TEST_IDLE_NET_TIMEOUT_MS);
+        }
     }
     pthread_mutex_unlock(&rcc->client->lock);
 }
@@ -2004,6 +2009,8 @@ void red_client_set_main(RedClient *client, MainChannelClient *mcc) {
 
 void red_client_semi_seamless_migrate_complete(RedClient *client)
 {
+    RingItem *link;
+
     pthread_mutex_lock(&client->lock);
     if (!client->during_target_migrate || client->seamless_migrate) {
         spice_error("unexpected");
@@ -2011,6 +2018,13 @@ void red_client_semi_seamless_migrate_complete(RedClient *client)
         return;
     }
     client->during_target_migrate = FALSE;
+    RING_FOREACH(link, &client->channels) {
+        RedChannelClient *rcc = SPICE_CONTAINEROF(link, RedChannelClient, client_link);
+
+        if (rcc->latency_monitor.timer) {
+            red_channel_client_start_ping_timer(rcc, PING_TEST_IDLE_NET_TIMEOUT_MS);
+        }
+    }
     pthread_mutex_unlock(&client->lock);
     reds_on_client_semi_seamless_migrate_complete(client);
 }
-- 
1.8.1.4