Simplify and improve graceful disconnect logic

src/Connection.c

@@ -24,7 +24,6 @@ OPUS_MULTISTREAM_CONFIGURATION HighQualityOpusConfig;
 int OriginalVideoBitrate;
 int AudioPacketDuration;
 bool AudioEncryptionEnabled;
-bool UserRequestedTermination;
 
 // Connection stages
 static const char* stageNames[STAGE_MAX] = {
@@ -56,12 +55,6 @@ void LiInterruptConnection(void) {
 
 // Stop the connection by undoing the step at the current stage and those before it
 void LiStopConnection(void) {
-    // If this was a fully complete connection and we haven't started any termination
-    // logic prior to this point, this termination is user requested.
-    if (stage == STAGE_MAX - 1 && !alreadyTerminated) {
-        UserRequestedTermination = true;
-    }
-
     // Disable termination callbacks now
     alreadyTerminated = true;
 
@@ -200,7 +193,6 @@ int LiStartConnection(PSERVER_INFORMATION serverInfo, PSTREAM_CONFIGURATION stre
 
     alreadyTerminated = false;
     ConnectionInterrupted = false;
-    UserRequestedTermination = false;
     
     // Validate the audio configuration
     if (MAGIC_BYTE_FROM_AUDIO_CONFIG(StreamConfig.audioConfiguration) != 0xCA ||

src/ControlStream.c

@@ -834,7 +834,13 @@ static void controlReceiveThreadFunc(void* context) {
                 // GFE 3.20.3.63 we don't get one for 10 seconds after we first get
                 // this termination message. The termination message should be reliable
                 // enough to end the stream now, rather than waiting for an explicit
-                // disconnect.
+                // disconnect. The server will also not acknowledge our disconnect
+                // message once it sends this message, so we mark the peer as fully
+                // disconnected now to avoid delays waiting for an ack that will
+                // never arrive.
+                PltLockMutex(&enetMutex);
+                enet_peer_disconnect_now(peer, 0);
+                PltUnlockMutex(&enetMutex);
                 ListenerCallbacks.connectionTerminated((int)terminationErrorCode);
                 free(ctlHdr);
                 return;
@@ -1054,19 +1060,9 @@ int stopControlStream(void) {
     }
 
     if (peer != NULL) {
-        if (UserRequestedTermination) {
         // Gracefully disconnect to ensure the remote host receives all of our final
         // outbound traffic, including any key up events that might be sent.
         gracefullyDisconnectEnetPeer(client, peer, CONTROL_STREAM_LINGER_TIMEOUT_SEC * 1000);
-            enet_peer_reset(peer);
-        }
-        else {
-            // This termination was requested by the remote host or caused due to a
-            // connection problem, so just do a quick abortive disconnect. The peer
-            // may be gone by this point.
-            enet_peer_disconnect_now(peer, 0);
-        }
-
         peer = NULL;
     }
     if (client != NULL) {

src/Limelight-internal.h

@@ -31,7 +31,6 @@ extern OPUS_MULTISTREAM_CONFIGURATION HighQualityOpusConfig;
 extern int OriginalVideoBitrate;
 extern int AudioPacketDuration;
 extern bool AudioEncryptionEnabled;
-extern bool UserRequestedTermination;
 
 #ifndef UINT24_MAX
 #define UINT24_MAX 0xFFFFFF

src/Misc.c

@@ -38,12 +38,14 @@ int serviceEnetHost(ENetHost* client, ENetEvent* event, enet_uint32 timeoutMs) {
 // This function performs a graceful disconnect, including lingering until outbound
 // traffic is acked (up until the linger timeout elapses).
 int gracefullyDisconnectEnetPeer(ENetHost* host, ENetPeer* peer, enet_uint32 lingerTimeoutMs) {
+    // Check if this peer is currently alive. We won't get another ENET_EVENT_TYPE_DISCONNECT
+    // event from ENet if the peer is dead. In that case, we'll do an abortive disconnect.
+    if (peer->state == ENET_PEER_STATE_CONNECTED) {
         ENetEvent event;
         int err;
 
-    // Begin the disconnection process. If this peer is already a zombie, we'll get an
-    // immediate disconnect event that will complete the process. If it's still alive,
-    // we'll get the disconnect event after all outgoing messages have been acked.
+        // Begin the disconnection process. We'll get ENET_EVENT_TYPE_DISCONNECT once
+        // the peer acks all outstanding reliable sends.
         enet_peer_disconnect_later(peer, 0);
 
         // We must use the internal function which lets us ignore pending interrupts.
@@ -53,7 +55,7 @@ int gracefullyDisconnectEnetPeer(ENetHost* host, ENetPeer* peer, enet_uint32 lin
                 enet_packet_destroy(event.packet);
                 break;
             case ENET_EVENT_TYPE_DISCONNECT:
-            Limelog("ENet peer disconnection is complete\n");
+                Limelog("ENet peer acknowledged disconnection\n");
                 return 0;
             default:
                 LC_ASSERT(false);
@@ -69,6 +71,12 @@ int gracefullyDisconnectEnetPeer(ENetHost* host, ENetPeer* peer, enet_uint32 lin
         }
 
         return -1;
+    }
+    else {
+        Limelog("ENet peer is already disconnected\n");
+        enet_peer_disconnect_now(peer, 0);
+        return 0;
+    }
 }
 
 int extractVersionQuadFromString(const char* string, int* quad) {