fix duplicated sessions

Author: lorux0

src/DCLPulse/Messaging/HandshakeHandler.cs

@@ -58,6 +58,11 @@ public void Handle(Dictionary<PeerIndex, PeerState> peers, PeerIndex from, Clien
             peer.ConnectionState = PeerConnectionState.AUTHENTICATED;
 
             peers[from] = peer;
+
+            if (identityBoard.TryGetPeerIndexByWallet(peer.WalletId, out PeerIndex duplicatedPeer))
+                if (duplicatedPeer != from)
+                    transport.Disconnect(duplicatedPeer, ITransport.DisconnectReason.DuplicateSession);
+
             identityBoard.Set(from, result.UserAddress);
             snapshotBoard.SetActive(from);
 
@@ -68,8 +73,6 @@ public void Handle(Dictionary<PeerIndex, PeerState> peers, PeerIndex from, Clien
                     Success = true,
                 },
             }, ITransport.PacketMode.RELIABLE));
-
-            DisconnectDuplicatedSessions(peers, from, result);
         }
         catch (Exception e)
         {
@@ -83,16 +86,4 @@ public void Handle(Dictionary<PeerIndex, PeerState> peers, PeerIndex from, Clien
             }, ITransport.PacketMode.RELIABLE));
         }
     }
-
-    private void DisconnectDuplicatedSessions(Dictionary<PeerIndex, PeerState> peers, PeerIndex from, AuthChainValidationResult result)
-    {
-        // TODO: could be improved if we index by walletId, although we would need to keep in sync both lists
-        foreach ((PeerIndex pi, PeerState ps) in peers)
-        {
-            if (!string.Equals(ps.WalletId, result.UserAddress, StringComparison.OrdinalIgnoreCase)) continue;
-
-            if (pi != from)
-                transport.Disconnect(pi, ITransport.DisconnectReason.DuplicateSession);
-        }
-    }
 }

src/DCLPulse/Peers/Simulation/IdentityBoard.cs

@@ -1,3 +1,5 @@
+using System.Collections.Concurrent;
+
 namespace Pulse.Peers.Simulation;
 
 /// <summary>
@@ -10,18 +12,28 @@ namespace Pulse.Peers.Simulation;
 /// </summary>
 public sealed class IdentityBoard(int maxPeers)
 {
-    private readonly string?[] walletIds = new string?[maxPeers];
+    private readonly string?[] walletsByPeerIds = new string?[maxPeers];
+    private readonly ConcurrentDictionary<string, PeerIndex> peerIdsByWallets = new (StringComparer.OrdinalIgnoreCase);
 
     public void Set(PeerIndex id, string walletId)
     {
-        Volatile.Write(ref walletIds[(int)id.Value], walletId);
+        Volatile.Write(ref walletsByPeerIds[(int)id.Value], walletId);
+        peerIdsByWallets[walletId] = id;
     }
 
-    public string? Get(PeerIndex id) =>
-        Volatile.Read(ref walletIds[(int)id.Value]);
+    public string? GetWalletIdByPeerIndex(PeerIndex id) =>
+        Volatile.Read(ref walletsByPeerIds[(int)id.Value]);
+
+    public bool TryGetPeerIndexByWallet(string walletId, out PeerIndex peerIndex) =>
+        peerIdsByWallets.TryGetValue(walletId, out peerIndex);
 
     public void Clear(PeerIndex id)
     {
-        Volatile.Write(ref walletIds[(int)id.Value], null);
+        string? walletId = GetWalletIdByPeerIndex(id);
+
+        if (walletId != null)
+            peerIdsByWallets.TryRemove(walletId, out _);
+
+        Volatile.Write(ref walletsByPeerIds[(int)id.Value], null);
     }
 }

src/DCLPulse/Peers/Simulation/PeerSimulation.cs

@@ -203,7 +203,7 @@ private void ProcessVisibleSubjects(
                 {
                     PlayerJoined = new PlayerJoined
                     {
-                        UserId = identityBoard.Get(entry.Subject),
+                        UserId = identityBoard.GetWalletIdByPeerIndex(entry.Subject),
                         ProfileVersion = profileBoard.Get(entry.Subject),
                         State = CreateFullState(entry.Subject, subjectSnapshot),
                     },

src/DCLPulseTests/IdentityBoardTests.cs

@@ -44,7 +44,7 @@ public void ConcurrentSetAndGet_ReadersNeverSeeTornValues()
                                         {
                                             for (var i = 0; i < MAX_PEERS; i++)
                                             {
-                                                string? value = board.Get(new PeerIndex((uint)i));
+                                                string? value = board.GetWalletIdByPeerIndex(new PeerIndex((uint)i));
 
                                                 // Must be either null (not yet written) or the exact expected value
                                                 if (value != null && value != expectedWallets[i])
@@ -104,7 +104,7 @@ public void ConcurrentSetAndClear_ReadersNeverSeeTornValues()
                                         {
                                             for (var i = 0; i < MAX_PEERS; i++)
                                             {
-                                                string? value = board.Get(new PeerIndex((uint)i));
+                                                string? value = board.GetWalletIdByPeerIndex(new PeerIndex((uint)i));
 
                                                 if (value != null && value != expectedWallets[i])
                                                     errors.Add($"Slot {i}: expected null or '{expectedWallets[i]}', got '{value}'");
@@ -141,7 +141,7 @@ public void ConcurrentReaders_AllSeeWrittenValueAfterWriterCompletes()
                                         {
                                             for (var i = 0; i < MAX_PEERS; i++)
                                             {
-                                                string? value = board.Get(new PeerIndex((uint)i));
+                                                string? value = board.GetWalletIdByPeerIndex(new PeerIndex((uint)i));
 
                                                 if (value != expectedWallets[i])
                                                     errors.Add($"Slot {i}: expected '{expectedWallets[i]}', got '{value}'");