From 747c8de0eda29d1d42f49021cd1cac97c9adb129 Mon Sep 17 00:00:00 2001
From: Jonathan Lennox <jonathan.lennox@8x8.com>
Date: Tue, 1 Oct 2024 17:18:19 -0400
Subject: [PATCH] Start writing to the ICE transport as soon as we have any
 validated pair.

---
 .../kotlin/org/jitsi/videobridge/Endpoint.kt  |  5 ++++-
 .../org/jitsi/videobridge/relay/Relay.kt      |  4 +++-
 .../videobridge/transport/ice/IceTransport.kt | 21 ++++++++++++++++++-
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/jvb/src/main/kotlin/org/jitsi/videobridge/Endpoint.kt b/jvb/src/main/kotlin/org/jitsi/videobridge/Endpoint.kt
index 40a7df8278..fcdb43b0ed 100644
--- a/jvb/src/main/kotlin/org/jitsi/videobridge/Endpoint.kt
+++ b/jvb/src/main/kotlin/org/jitsi/videobridge/Endpoint.kt
@@ -430,7 +430,7 @@ class Endpoint @JvmOverloads constructor(
             }
         }
         iceTransport.eventHandler = object : IceTransport.EventHandler {
-            override fun connected() {
+            override fun writeable() {
                 logger.info("ICE connected")
                 transceiver.setOutgoingPacketHandler(object : PacketHandler {
                     override fun processPacket(packetInfo: PacketInfo) {
@@ -442,6 +442,9 @@ class Endpoint @JvmOverloads constructor(
                 TaskPools.IO_POOL.execute(dtlsTransport::startDtlsHandshake)
             }
 
+            override fun connected() {
+            }
+
             override fun failed() {
             }
 
diff --git a/jvb/src/main/kotlin/org/jitsi/videobridge/relay/Relay.kt b/jvb/src/main/kotlin/org/jitsi/videobridge/relay/Relay.kt
index 3f1052bee1..a2379edad4 100644
--- a/jvb/src/main/kotlin/org/jitsi/videobridge/relay/Relay.kt
+++ b/jvb/src/main/kotlin/org/jitsi/videobridge/relay/Relay.kt
@@ -391,7 +391,7 @@ class Relay @JvmOverloads constructor(
             }
         }
         iceTransport.eventHandler = object : IceTransport.EventHandler {
-            override fun connected() {
+            override fun writeable() {
                 logger.info("ICE connected")
                 transceiver.setOutgoingPacketHandler(object : PacketHandler {
                     override fun processPacket(packetInfo: PacketInfo) {
@@ -403,6 +403,8 @@ class Relay @JvmOverloads constructor(
                 TaskPools.IO_POOL.execute(dtlsTransport::startDtlsHandshake)
             }
 
+            override fun connected() {}
+
             override fun failed() {}
 
             override fun consentUpdated(time: Instant) {
diff --git a/jvb/src/main/kotlin/org/jitsi/videobridge/transport/ice/IceTransport.kt b/jvb/src/main/kotlin/org/jitsi/videobridge/transport/ice/IceTransport.kt
index 9f7ae36245..9d9d661956 100755
--- a/jvb/src/main/kotlin/org/jitsi/videobridge/transport/ice/IceTransport.kt
+++ b/jvb/src/main/kotlin/org/jitsi/videobridge/transport/ice/IceTransport.kt
@@ -94,6 +94,13 @@ class IceTransport @JvmOverloads constructor(
     @JvmField
     var eventHandler: EventHandler? = null
 
+    /**
+     * Whether or not it is possible to write to this [IceTransport].
+     *
+     * This happens as soon as any candidate pair is validated, and happens (usually) before iceConnected.
+     */
+    private val iceWriteable = AtomicBoolean(false)
+
     /**
      * Whether or not this [IceTransport] has connected.
      */
@@ -106,6 +113,8 @@ class IceTransport @JvmOverloads constructor(
 
     fun hasFailed(): Boolean = iceFailed.get()
 
+    fun isWriteable(): Boolean = iceWriteable.get()
+
     fun isConnected(): Boolean = iceConnected.get()
 
     /**
@@ -264,6 +273,7 @@ class IceTransport @JvmOverloads constructor(
         put("nominationStrategy", IceConfig.config.nominationStrategy.toString())
         put("advertisePrivateCandidates", IceConfig.config.advertisePrivateCandidates)
         put("closed", !running.get())
+        put("iceWriteable", iceWriteable.get())
         put("iceConnected", iceConnected.get())
         put("iceFailed", iceFailed.get())
         putAll(packetStats.toJson())
@@ -375,7 +385,11 @@ class IceTransport @JvmOverloads constructor(
     }
 
     private fun iceStreamPairChanged(ev: PropertyChangeEvent) {
-        if (IceMediaStream.PROPERTY_PAIR_CONSENT_FRESHNESS_CHANGED == ev.propertyName) {
+        if (IceMediaStream.PROPERTY_PAIR_VALIDATED == ev.propertyName) {
+            if (iceWriteable.compareAndSet(false, true)) {
+                eventHandler?.writeable()
+            }
+        } else if (IceMediaStream.PROPERTY_PAIR_CONSENT_FRESHNESS_CHANGED == ev.propertyName) {
             /* TODO: Currently ice4j only triggers this event for the selected
              * pair, but should we double-check the pair anyway?
              */
@@ -439,6 +453,11 @@ class IceTransport @JvmOverloads constructor(
     }
 
     interface EventHandler {
+        /**
+         * Notify the event handler that it is possible to write to the ICE stack
+         */
+        fun writeable()
+
         /**
          * Notify the event handler that ICE connected successfully
          */