From db7f5724f7830ecb027f87b6181fc4ace1bab89b Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Thu, 27 Oct 2016 21:50:29 -0700
Subject: [PATCH 1/2] output last seq number and last socket before readyRead
 sticks

---
 libraries/networking/src/udt/Socket.cpp | 9 +++++++++
 libraries/networking/src/udt/Socket.h   | 3 +++
 2 files changed, 12 insertions(+)

diff --git a/libraries/networking/src/udt/Socket.cpp b/libraries/networking/src/udt/Socket.cpp
index 43bd7dd973..bf2a3fe6d2 100644
--- a/libraries/networking/src/udt/Socket.cpp
+++ b/libraries/networking/src/udt/Socket.cpp
@@ -306,6 +306,11 @@ void Socket::checkForReadyReadBackup() {
     if (_udpSocket.hasPendingDatagrams()) {
         qCDebug(networking) << "Socket::checkForReadyReadBackup() detected blocked readyRead signal. Flushing pending datagrams.";
 
+        // so that birarda can possibly figure out how the heck we get into this state in the first place
+        // output the sequence number and socket address of the last processed packet
+        qCDebug(networking) << "Socket::checkForReadyReadyBackup() last sequence number"
+            << (uint32_t) _lastReceivedSequenceNumber << "from" << _lastPacketSockAddr;
+
         // drop all of the pending datagrams on the floor
         while (_udpSocket.hasPendingDatagrams()) {
             _udpSocket.readDatagram(nullptr, 0);
@@ -373,6 +378,10 @@ void Socket::readPendingDatagrams() {
             auto packet = Packet::fromReceivedPacket(std::move(buffer), packetSizeWithHeader, senderSockAddr);
             packet->setReceiveTime(receiveTime);
 
+            // save the sequence number and socket for this packet, in case this is the packet that sticks readyRead
+            _lastPacketSockAddr = senderSockAddr;
+            _lastReceivedSequenceNumber = packet->getSequenceNumber();
+
             // call our verification operator to see if this packet is verified
             if (!_packetFilterOperator || _packetFilterOperator(*packet)) {
                 if (packet->isReliable()) {
diff --git a/libraries/networking/src/udt/Socket.h b/libraries/networking/src/udt/Socket.h
index a811d78958..24f0b8afaf 100644
--- a/libraries/networking/src/udt/Socket.h
+++ b/libraries/networking/src/udt/Socket.h
@@ -144,6 +144,9 @@ private:
     std::unique_ptr<CongestionControlVirtualFactory> _ccFactory { new CongestionControlFactory<TCPVegasCC>() };
 
     bool _shouldChangeSocketOptions { true };
+
+    SequenceNumber _lastReceivedSequenceNumber;
+    HifiSockAddr _lastPacketSockAddr;
     
     friend UDTTest;
 };

From 20f042a15a134455e36dbb837a8a465a432c1161 Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Thu, 27 Oct 2016 22:10:32 -0700
Subject: [PATCH 2/2] add slightly more information to last packet debug in
 Socket

---
 libraries/networking/src/udt/Socket.cpp | 11 ++++++++---
 libraries/networking/src/udt/Socket.h   |  1 +
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/libraries/networking/src/udt/Socket.cpp b/libraries/networking/src/udt/Socket.cpp
index bf2a3fe6d2..fbf2a1c86a 100644
--- a/libraries/networking/src/udt/Socket.cpp
+++ b/libraries/networking/src/udt/Socket.cpp
@@ -309,7 +309,9 @@ void Socket::checkForReadyReadBackup() {
         // so that birarda can possibly figure out how the heck we get into this state in the first place
         // output the sequence number and socket address of the last processed packet
         qCDebug(networking) << "Socket::checkForReadyReadyBackup() last sequence number"
-            << (uint32_t) _lastReceivedSequenceNumber << "from" << _lastPacketSockAddr;
+            << (uint32_t) _lastReceivedSequenceNumber << "from" << _lastPacketSockAddr << "-"
+            << _lastPacketSizeRead << "bytes";
+
 
         // drop all of the pending datagrams on the floor
         while (_udpSocket.hasPendingDatagrams()) {
@@ -339,6 +341,10 @@ void Socket::readPendingDatagrams() {
         auto sizeRead = _udpSocket.readDatagram(buffer.get(), packetSizeWithHeader,
                                                 senderSockAddr.getAddressPointer(), senderSockAddr.getPortPointer());
 
+        // save information for this packet, in case it is the one that sticks readyRead
+        _lastPacketSizeRead = sizeRead;
+        _lastPacketSockAddr = senderSockAddr;
+
         if (sizeRead <= 0) {
             // we either didn't pull anything for this packet or there was an error reading (this seems to trigger
             // on windows even if there's not a packet available)
@@ -378,8 +384,7 @@ void Socket::readPendingDatagrams() {
             auto packet = Packet::fromReceivedPacket(std::move(buffer), packetSizeWithHeader, senderSockAddr);
             packet->setReceiveTime(receiveTime);
 
-            // save the sequence number and socket for this packet, in case this is the packet that sticks readyRead
-            _lastPacketSockAddr = senderSockAddr;
+            // save the sequence number in case this is the packet that sticks readyRead
             _lastReceivedSequenceNumber = packet->getSequenceNumber();
 
             // call our verification operator to see if this packet is verified
diff --git a/libraries/networking/src/udt/Socket.h b/libraries/networking/src/udt/Socket.h
index 24f0b8afaf..1919e00b41 100644
--- a/libraries/networking/src/udt/Socket.h
+++ b/libraries/networking/src/udt/Socket.h
@@ -145,6 +145,7 @@ private:
 
     bool _shouldChangeSocketOptions { true };
 
+    int _lastPacketSizeRead { 0 };
     SequenceNumber _lastReceivedSequenceNumber;
     HifiSockAddr _lastPacketSockAddr;