conncheck: clear the retransmit flag when the stun list is empty

This patch ensures that the retransmit flag is more tightly in sync with
the stun transaction list, by now clearing it when the list becomes
empty. It makes the code a bit more readable by dropping some cases. In
a couple of places, the retransmit flag was also used as a way to
compare the priority of a pair and the priority of the selected pair.

1 files changed, 13 insertions, 29 deletions

diff --git a/agent/conncheck.c b/agent/conncheck.c
index f2839bb..81705dc 100644
--- a/agent/conncheck.c
+++ b/agent/conncheck.c
@@ -621,6 +621,8 @@ priv_remove_stun_transaction (CandidateCheckPair *pair,
   priv_forget_stun_transaction (stun, component);
   pair->stun_transactions = g_slist_remove (pair->stun_transactions, stun);
   priv_free_stun_transaction (stun);
+  if (pair->stun_transactions == NULL)
+    pair->retransmit = FALSE;
 }
 
 /*
@@ -639,6 +641,7 @@ priv_free_all_stun_transactions (CandidateCheckPair *pair,
     g_slist_foreach (pair->stun_transactions, priv_forget_stun_transaction, component);
   g_slist_free_full (pair->stun_transactions, priv_free_stun_transaction);
   pair->stun_transactions = NULL;
+  pair->retransmit = FALSE;
 }
 
 static void
@@ -2281,10 +2284,9 @@ static void priv_mark_pair_nominated (NiceAgent *agent, NiceStream *stream, Nice
 
         /* This pair is not always in the triggered check list, for
          * example if it is in-progress with a lower priority than an
-         * already nominated pair, and with its retransmit flag unset.
-         * Is that case, it is not rescheduled for a connection check,
-         * see function priv_schedule_triggered_check(), case
-         * NICE_CHECK_IN_PROGRESS.
+         * already nominated pair.  Is that case, it is not rescheduled
+         * for a connection check, see function
+         * priv_schedule_triggered_check(), case NICE_CHECK_IN_PROGRESS.
          */
         pair->mark_nominated_on_response_arrival = TRUE;
         nice_debug ("Agent %p : pair %p (%s) is %s, "
@@ -3049,21 +3051,10 @@ static guint priv_prune_pending_checks (NiceAgent *agent, NiceStream *stream, Ni
     else if (p->state == NICE_CHECK_IN_PROGRESS) {
       if (p->priority < priority) {
         priv_remove_pair_from_triggered_check_queue (agent, p);
-        if (p->retransmit && p->stun_transactions) {
-          p->retransmit  = FALSE;
+        if (p->retransmit) {
+          p->retransmit = FALSE;
           nice_debug ("Agent %p : pair %p will not be retransmitted.",
               agent, p);
-        } else if (p->retransmit) {
-          /* Pair in-progress, but stun request not yet sent: for
-           * example retriggered checks on role conflicted pairs that
-           * were previously in-progress/retransmit=yes, and put on
-           * triggered check queue stayed in-progress, with no stun
-           * ongoing.
-           */
-          nice_debug ("Agent %p : pair %p removed.", agent, p);
-          candidate_check_pair_free (agent, p);
-          stream->conncheck_list = g_slist_delete_link(stream->conncheck_list,
-              i);
         }
       } else {
         /* We must keep the higher priority pairs running because if a udp
@@ -3081,12 +3072,6 @@ static guint priv_prune_pending_checks (NiceAgent *agent, NiceStream *stream, Ni
         in_progress++;
       }
     }
-    /* A triggered check on a failed pair will depend on the retransmit
-     * flag, so on the relative priority of this pair and the nominated
-     * pair.
-     */
-    else if (p->state == NICE_CHECK_FAILED)
-      p->retransmit = (p->priority > priority ? TRUE : FALSE);
     i = next;
   }
 
@@ -3143,19 +3128,18 @@ static gboolean priv_schedule_triggered_check (NiceAgent *agent, NiceStream *str
              * for that pair.  The controlling role of this new check may
              * be different from the role of this cancelled check.
              *
-             * note: the flag retransmit unset means that
-             * another pair, with a higher priority is already nominated,
-             * so there's no reason to recheck this pair, since it can in
-             * no way replace the nominated one.
+             * When another pair, with a higher priority is already
+             * nominated, so there's no reason to recheck this pair,
+             * since it can in no way replace the nominated one.
              */
-            if (p->retransmit) {
+            if (p->priority > component->selected_pair.priority) {
               nice_debug ("Agent %p : pair %p added for a triggered check.",
                   agent, p);
               priv_add_pair_to_triggered_check_queue (agent, p);
             }
             break;
           case NICE_CHECK_FAILED:
-            if (p->retransmit) {
+            if (p->priority > component->selected_pair.priority) {
                 nice_debug ("Agent %p : pair %p added for a triggered check.",
                     agent, p);
                 priv_add_pair_to_triggered_check_queue (agent, p);