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fix: eliminate bad use-after-free(destroy) pattern #1068

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Merged
merged 2 commits into from
Aug 19, 2021
Merged

fix: eliminate bad use-after-free(destroy) pattern #1068

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d2dc321
fix: eliminate bad use-after-free(destroy) pattern
0xFA11 Aug 18, 2021
00a0e05
remove obsolete comment
0xFA11 Aug 18, 2021
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12 changes: 12 additions & 0 deletions com.unity.netcode.gameobjects/Runtime/Core/NetworkObject.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -380,8 +380,20 @@ public static void NetworkHide(List<NetworkObject> networkObjects, ulong clientI
}
}

private bool m_ApplicationQuitting = false;
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if you wanted to avoid the instance memory, you could do this statically:

static class ApplicationQuitHelper
{
    public static bool ApplicationQuitting { get; private set; }

    [RuntimeInitializeOnLoadMethod]
    static void RegisterQuitCallback()
    {
        Application.quitting += ()=> ApplicationQuitting = true;
    }
}


private void OnApplicationQuit()
{
m_ApplicationQuitting = true;
}

private void OnDestroy()
{
if (m_ApplicationQuitting)
{
return;
}

if (NetworkManager != null && NetworkManager.IsListening && NetworkManager.IsServer == false && IsSpawned)
{
throw new NotServerException($"Destroy a spawned {nameof(NetworkObject)} on a non-host client is not valid. Call {nameof(Destroy)} or {nameof(Despawn)} on the server/host instead.");
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14 changes: 5 additions & 9 deletions com.unity.netcode.gameobjects/Runtime/Spawning/NetworkSpawnManager.cs
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Expand Up @@ -685,8 +685,12 @@ internal void OnDespawnObject(NetworkObject networkObject, bool destroyGameObjec
}
}

var gobj = networkObject.gameObject;
if (SpawnedObjects.Remove(networkObject.NetworkObjectId))
{
SpawnedObjectsList.Remove(networkObject);
}

var gobj = networkObject.gameObject;
if (destroyGameObject && gobj != null)
{
if (NetworkManager.PrefabHandler.ContainsHandler(networkObject))
Expand All @@ -698,14 +702,6 @@ internal void OnDespawnObject(NetworkObject networkObject, bool destroyGameObjec
UnityEngine.Object.Destroy(gobj);
}
}

// for some reason, we can get down here and SpawnedObjects for this
// networkId will no longer be here, even as we check this at the start
// of the function
if (SpawnedObjects.Remove(networkObject.NetworkObjectId))
{
SpawnedObjectsList.Remove(networkObject);
}
}
}
}