From d5e0950ec6fc3a803bf8918be72cff7463299ba0 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Mon, 18 Apr 2016 16:27:50 -0400
Subject: [PATCH] Wrap enet_host_service() to hide the logic required to make
 retransmissions work

---
 src/ControlStream.c      |  6 +++---
 src/Limelight-internal.h |  3 +++
 src/Misc.c               | 20 ++++++++++++++++++++
 src/RtspConnection.c     |  6 +++---
 4 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/src/ControlStream.c b/src/ControlStream.c
index 175037a..5fd166c 100644
--- a/src/ControlStream.c
+++ b/src/ControlStream.c
@@ -301,7 +301,7 @@ static int sendMessageEnet(short ptype, short paylen, const void* payload) {
     memcpy(&packet[1], payload, paylen);
 
     // Gen 5+ servers do control protocol over ENet instead of TCP
-    while ((err = enet_host_service(client, &event, 0)) > 0) {
+    while ((err = serviceEnetHost(client, &event, 0)) > 0) {
         if (event.type == ENET_EVENT_TYPE_RECEIVE) {
             enet_packet_destroy(event.packet);
         }
@@ -391,7 +391,7 @@ static int sendMessageAndDiscardReply(short ptype, short paylen, const void* pay
             return 0;
         }
 
-        if (enet_host_service(client, &event, CONTROL_STREAM_TIMEOUT_SEC * 1000) <= 0 ||
+        if (serviceEnetHost(client, &event, CONTROL_STREAM_TIMEOUT_SEC * 1000) <= 0 ||
             event.type != ENET_EVENT_TYPE_RECEIVE) {
             PltUnlockMutex(&enetMutex);
             return 0;
@@ -642,7 +642,7 @@ int startControlStream(void) {
         }
 
         // Wait for the connect to complete
-        if (enet_host_service(client, &event, CONTROL_STREAM_TIMEOUT_SEC * 1000) <= 0 ||
+        if (serviceEnetHost(client, &event, CONTROL_STREAM_TIMEOUT_SEC * 1000) <= 0 ||
             event.type != ENET_EVENT_TYPE_CONNECT) {
             Limelog("RTSP: Failed to connect to UDP port 47999\n");
             enet_peer_reset(peer);
diff --git a/src/Limelight-internal.h b/src/Limelight-internal.h
index 448f93c..f8712aa 100644
--- a/src/Limelight-internal.h
+++ b/src/Limelight-internal.h
@@ -6,6 +6,8 @@
 #include "PlatformThreads.h"
 #include "Video.h"
 
+#include <enet/enet.h>
+
 // Common globals
 extern char* RemoteAddrString;
 extern struct sockaddr_storage RemoteAddr;
@@ -18,6 +20,7 @@ extern AUDIO_RENDERER_CALLBACKS AudioCallbacks;
 extern int NegotiatedVideoFormat;
 
 int isBeforeSignedInt(int numA, int numB, int ambiguousCase);
+int serviceEnetHost(ENetHost* client, ENetEvent* event, enet_uint32 timeoutMs);
 
 void fixupMissingCallbacks(PDECODER_RENDERER_CALLBACKS* drCallbacks, PAUDIO_RENDERER_CALLBACKS* arCallbacks,
     PCONNECTION_LISTENER_CALLBACKS* clCallbacks);
diff --git a/src/Misc.c b/src/Misc.c
index 4069f65..1e1fd53 100644
--- a/src/Misc.c
+++ b/src/Misc.c
@@ -1,5 +1,25 @@
 #include "Limelight-internal.h"
 
+#define ENET_SERVICE_RETRIES 10
+
+// This function wraps enet_host_service() and hides the fact that it must be called
+// multiple times for retransmissions to work correctly. It is meant to be a drop-in
+// replacement for enet_host_service().
+int serviceEnetHost(ENetHost* client, ENetEvent* event, enet_uint32 timeoutMs) {
+    int i;
+    int ret;
+    
+    // We need to call enet_host_service() multiple times to make sure retransmissions happen
+    for (i = 0; i < ENET_SERVICE_RETRIES; i++) {
+        ret = enet_host_service(client, event, timeoutMs / ENET_SERVICE_RETRIES);
+        if (ret != 0 || timeoutMs == 0) {
+            break;
+        }
+    }
+    
+    return ret;
+}
+
 int isBeforeSignedInt(int numA, int numB, int ambiguousCase) {
     // This should be the common case for most callers
     if (numA == numB) {
diff --git a/src/RtspConnection.c b/src/RtspConnection.c
index 2e5a2c1..a67ff8f 100644
--- a/src/RtspConnection.c
+++ b/src/RtspConnection.c
@@ -141,7 +141,7 @@ static int transactRtspMessageEnet(PRTSP_MESSAGE request, PRTSP_MESSAGE response
     }
     
     // Wait for a reply
-    if (enet_host_service(client, &event, RTSP_TIMEOUT_SEC * 1000) <= 0 ||
+    if (serviceEnetHost(client, &event, RTSP_TIMEOUT_SEC * 1000) <= 0 ||
         event.type != ENET_EVENT_TYPE_RECEIVE) {
         Limelog("Failed to receive RTSP reply\n");
         ret = 0;
@@ -162,7 +162,7 @@ static int transactRtspMessageEnet(PRTSP_MESSAGE request, PRTSP_MESSAGE response
     // Wait for the payload if we're expecting some
     if (expectingPayload) {
         // The payload comes in a second packet
-        if (enet_host_service(client, &event, RTSP_TIMEOUT_SEC * 1000) <= 0 ||
+        if (serviceEnetHost(client, &event, RTSP_TIMEOUT_SEC * 1000) <= 0 ||
             event.type != ENET_EVENT_TYPE_RECEIVE) {
             Limelog("Failed to receive RTSP reply payload\n");
             ret = 0;
@@ -490,7 +490,7 @@ int performRtspHandshake(void) {
         }
     
         // Wait for the connect to complete
-        if (enet_host_service(client, &event, RTSP_TIMEOUT_SEC * 1000) <= 0 ||
+        if (serviceEnetHost(client, &event, RTSP_TIMEOUT_SEC * 1000) <= 0 ||
             event.type != ENET_EVENT_TYPE_CONNECT) {
             Limelog("RTSP: Failed to connect to UDP port 48010\n");
             enet_peer_reset(peer);