From bf839ca2912b20f7a080be62c1786c4fda47a90d Mon Sep 17 00:00:00 2001
From: Simon Walton <simon@highfidelity.io>
Date: Fri, 24 Aug 2018 16:53:38 -0700
Subject: [PATCH] Handle _unfilteredHandlers first upon processing datagrams

---
 libraries/networking/src/udt/Socket.cpp | 41 +++++++++++++++----------
 libraries/networking/src/udt/Socket.h   |  4 +--
 2 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/libraries/networking/src/udt/Socket.cpp b/libraries/networking/src/udt/Socket.cpp
index 5b64cc0716..162b045a6e 100644
--- a/libraries/networking/src/udt/Socket.cpp
+++ b/libraries/networking/src/udt/Socket.cpp
@@ -344,7 +344,7 @@ void Socket::readPendingDatagrams() {
             continue;
         }
 
-        _incomingDatagrams.push({ senderAddress, senderPort, packetSizeWithHeader,
+        _incomingDatagrams.push_back({ senderAddress, senderPort, packetSizeWithHeader,
             std::move(buffer), receiveTime });
         ++packetsRead;
 
@@ -361,6 +361,28 @@ void Socket::processPendingDatagrams(int) {
     // setup a HifiSockAddr to read into
     HifiSockAddr senderSockAddr;
 
+    // Process unfiltered packets first.
+    for (auto datagramIter = _incomingDatagrams.begin(); datagramIter != _incomingDatagrams.end(); ++datagramIter) {
+        senderSockAddr.setAddress(datagramIter->_senderAddress);
+        senderSockAddr.setPort(datagramIter->_senderPort);
+        auto it = _unfilteredHandlers.find(senderSockAddr);
+        if (it != _unfilteredHandlers.end()) {
+            // we have a registered unfiltered handler for this HifiSockAddr (eg. STUN packet) - call that and return
+            if (it->second) {
+                auto basePacket = BasePacket::fromReceivedPacket(std::move(datagramIter->_datagram),
+                    datagramIter->_datagramLength,
+                    senderSockAddr);
+                basePacket->setReceiveTime(datagramIter->_receiveTime);
+                it->second(std::move(basePacket));
+            }
+
+            datagramIter = _incomingDatagrams.erase(datagramIter);
+            if (datagramIter == _incomingDatagrams.end()) {
+                break;
+            }
+        }
+    }
+
     while (!_incomingDatagrams.empty()) {
         auto& datagram = _incomingDatagrams.front();
         senderSockAddr.setAddress(datagram._senderAddress);
@@ -370,19 +392,6 @@ void Socket::processPendingDatagrams(int) {
 
         auto it = _unfilteredHandlers.find(senderSockAddr);
 
-        if (it != _unfilteredHandlers.end()) {
-            // we have a registered unfiltered handler for this HifiSockAddr (eg. STUN packet) - call that and return
-            if (it->second) {
-                auto basePacket = BasePacket::fromReceivedPacket(std::move(datagram._datagram), datagramSize,
-                    senderSockAddr);
-                basePacket->setReceiveTime(datagram._receiveTime);
-                it->second(std::move(basePacket));
-            }
-
-            _incomingDatagrams.pop();
-            continue;
-        }
-
         // we're reading a packet so re-start the readyRead backup timer
         _readyReadBackupTimer->start();
 
@@ -427,7 +436,7 @@ void Socket::processPendingDatagrams(int) {
                         qCDebug(networking) << "Can't process packet: version" << (unsigned int)NLPacket::versionInHeader(*packet)
                             << ", type" << NLPacket::typeInHeader(*packet);
 #endif
-                        _incomingDatagrams.pop();
+                        _incomingDatagrams.pop_front();
                         continue;
                     }
                 }
@@ -444,7 +453,7 @@ void Socket::processPendingDatagrams(int) {
             }
         }
 
-        _incomingDatagrams.pop();
+        _incomingDatagrams.pop_front();
     }
 }
 
diff --git a/libraries/networking/src/udt/Socket.h b/libraries/networking/src/udt/Socket.h
index 078863663f..ef4a457116 100644
--- a/libraries/networking/src/udt/Socket.h
+++ b/libraries/networking/src/udt/Socket.h
@@ -17,7 +17,7 @@
 #include <functional>
 #include <unordered_map>
 #include <mutex>
-#include <queue>
+#include <list>
 
 #include <QtCore/QObject>
 #include <QtCore/QTimer>
@@ -156,7 +156,7 @@ private:
         p_high_resolution_clock::time_point _receiveTime;
     };
 
-    std::queue<Datagram> _incomingDatagrams;
+    std::list<Datagram> _incomingDatagrams;
     int _maxDatagramsRead { 0 };
     
     friend UDTTest;