From 7fb4f037647ed66405b69106186d29c31c6cd6e1 Mon Sep 17 00:00:00 2001 From: ivan tkachenko Date: Fri, 8 Aug 2025 20:42:06 +0300 Subject: [PATCH] fix delegates lifetime: unsubscribe stale handlers on network despawn CSync leaves stale change handlers after quitting the hosted game. When the host quits the game back to the main menu, ConfigSyncBehaviour despawns and gets destroyed by Unity (not by .NET GC), but any delegates connected to events in OnNetworkSpawn method remain and go stale. So next time a player hosts a lobby without shutting down and re-launching the game completely, when any of subscribed config files or config entries change, stale delegates execute and try to assign to a dead NetworkList _deltas[index]. Of course it results in an exception being logged to the console by BepInEx (which wraps event handler invocation in a try-catch). To fix this, store subscribed delegates, and properly unsubscribe them during despawn. Note that NetworkList and _syncEnabled variable can not be cleared/reset due to Unity issue which only got resolved in the most recent version. Lethal Company v73 updated Unity Netcode for GameObjects (NGO) to 1.12.0, but the fix is available for NGO 1.14.0+ only. References: - https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/delegates/using-delegates - https://github.com/Unity-Technologies/com.unity.netcode.gameobjects/pull/3502 Fixes #13 --- CSync/CSync/Lib/ConfigSyncBehaviour.cs | 88 +++++++++++++++++++++----- 1 file changed, 72 insertions(+), 16 deletions(-) diff --git a/CSync/CSync/Lib/ConfigSyncBehaviour.cs b/CSync/CSync/Lib/ConfigSyncBehaviour.cs index 981cade..d77c1b9 100644 --- a/CSync/CSync/Lib/ConfigSyncBehaviour.cs +++ b/CSync/CSync/Lib/ConfigSyncBehaviour.cs @@ -1,3 +1,4 @@ +using BepInEx.Configuration; using System; using System.Collections.Generic; using System.Diagnostics.CodeAnalysis; @@ -37,6 +38,7 @@ public bool SyncEnabled private readonly NetworkVariable _syncEnabled = new(); private NetworkList _deltas = null!; + private readonly List _syncedEntryListeners = new(); [MemberNotNull(nameof(EntryContainer))] private void EnsureEntryContainer() @@ -51,6 +53,42 @@ private void Awake() _deltas = new NetworkList(); } + // Helper class to maintain event subscriptions. + // SyncedEntryDelta is a struct which can't be copied around, so it has to be stored by list+index. + sealed class SyncedEntryListener : IDisposable + { + private readonly NetworkList deltas; + private readonly int index; + private readonly SyncedEntryBase syncedEntryBase; + + public SyncedEntryListener(NetworkList deltas, int index, SyncedEntryBase syncedEntryBase) + { + this.deltas = deltas; + this.index = index; + this.syncedEntryBase = syncedEntryBase; + + syncedEntryBase.BoxedEntry.ConfigFile.SettingChanged += OnSettingChanged; + syncedEntryBase.SyncEnabledChanged += OnEntrySyncEnabledChanged; + } + + public void Dispose() + { + syncedEntryBase.BoxedEntry.ConfigFile.SettingChanged -= OnSettingChanged; + syncedEntryBase.SyncEnabledChanged -= OnEntrySyncEnabledChanged; + } + + void OnSettingChanged(object sender, SettingChangedEventArgs args) + { + if (!ReferenceEquals(syncedEntryBase.BoxedEntry, args.ChangedSetting)) return; + deltas[index] = syncedEntryBase.ToDelta(); + } + + void OnEntrySyncEnabledChanged(object sender, EventArgs args) + { + deltas[index] = syncedEntryBase.ToDelta(); + } + } + public override void OnNetworkSpawn() { base.OnNetworkSpawn(); @@ -65,17 +103,7 @@ public override void OnNetworkSpawn() { var currentIndex = _deltas.Count; _deltas.Add(syncedEntryBase.ToDelta()); - - syncedEntryBase.BoxedEntry.ConfigFile.SettingChanged += (_, args) => - { - if (!ReferenceEquals(syncedEntryBase.BoxedEntry, args.ChangedSetting)) return; - _deltas[currentIndex] = syncedEntryBase.ToDelta(); - }; - - syncedEntryBase.SyncEnabledChanged += (_, args) => - { - _deltas[currentIndex] = syncedEntryBase.ToDelta(); - }; + _syncedEntryListeners.Add(new(_deltas, currentIndex, syncedEntryBase)); } InitialSyncCompletedHandler?.Invoke(this, EventArgs.Empty); @@ -98,16 +126,44 @@ public override void OnNetworkSpawn() public override void OnNetworkDespawn() { + EnsureEntryContainer(); + + if (IsServer) + { + foreach (var listener in _syncedEntryListeners) + { + listener.Dispose(); + } + + _syncedEntryListeners.Clear(); + + // NetworkList and NetworkVariable can not be modified now because the network manager has already shut down. + // See https://github.com/Unity-Technologies/com.unity.netcode.gameobjects/pull/3502 + // The fix applies to NGO 1.14.0+, but Lethal Company v73 is on NGO 1.12.0 + // Should not be needed anyway, since this component isn't being reused between network sessions. + // _deltas.Clear(); + // _syncEnabled.Value = false; + } + else if (IsClient) + { + DisableOverrides(); + + foreach (var delta in _deltas) + { + ResetOverrideValue(delta); + } + + _deltas.OnListChanged -= OnClientDeltaListChanged; + _syncEnabled.OnValueChanged -= OnSyncEnabledChanged; + } + base.OnNetworkDespawn(); } public override void OnDestroy() { - DisableOverrides(); - foreach (var delta in _deltas) - { - ResetOverrideValue(delta); - } + // The content of this method has moved to OnNetworkDespawn. + // Keep this method around for ABI compatibility though. base.OnDestroy(); }