Occasional Unhandled Exceptions

[elcosmelco]

I am using the client in a Xamarin Forms project on an Android 8.0 device and about 70% of the time things run as expected. The other 30% of the times I launch the app it crashes immediately with an unhandled exception stating "An item with the same key has already been added. Key: System.Net.Mqtt.Sdk.Storage.RetainedMessage". I've tried try/catch on everything to do with the client object and it doesn't catch it.

The call stack is as following:
at System.ThrowHelper.ThrowAddingDuplicateWithKeyArgumentException (System.Object key) [0x00006] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Collections.Generic.Dictionary'2[TKey,TValue].TryInsert (TKey key, TValue value, System.Collections.Generic.InsertionBehavior behavior) [0x000ad] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Collections.Generic.Dictionary'2[TKey,TValue].Add (TKey key, TValue value) [0x00000] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Net.Mqtt.Sdk.Storage.InMemoryRepositoryProvider.GetRepository[T] () [0x0006a] in C:\Code\Xamarin\mqtt\src\Client\Sdk\Storage\InMemoryRepositoryProvider.cs:24 at System.Net.Mqtt.Sdk.Flows.ClientProtocolFlowProvider.InitializeFlows () [0x00012] in C:\Code\Xamarin\mqtt\src\Client\Sdk\Flows\ClientProtocolFlowProvider.cs:21 at System.Net.Mqtt.Sdk.Flows.ProtocolFlowProvider.GetFlows () [0x00008] in C:\Code\Xamarin\mqtt\src\Client\Sdk\Flows\ProtocolFlowProvider.cs:64 at System.Net.Mqtt.Sdk.Flows.ProtocolFlowProvider.GetFlow (System.Net.Mqtt.Sdk.Packets.MqttPacketType packetType) [0x0002a] in C:\Code\Xamarin\mqtt\src\Client\Sdk\Flows\ProtocolFlowProvider.cs:40 at System.Net.Mqtt.Sdk.ClientPacketListener+<DispatchPacketAsync>d__23.MoveNext () [0x0002a] in C:\Code\Xamarin\mqtt\src\Client\Sdk\ClientPacketListener.cs:194 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x0003e] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Runtime.CompilerServices.ConfiguredTaskAwaitable+ConfiguredTaskAwaiter.GetResult () [0x00000] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Net.Mqtt.Sdk.ClientPacketListener+<<ListenNextPackets>b__17_0>d.MoveNext () [0x0002c] in C:\Code\Xamarin\mqtt\src\Client\Sdk\ClientPacketListener.cs:108 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_1 (System.Object state) [0x00000] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context (System.Object state) [0x00007] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x00071] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x00000] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem () [0x00021] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Threading.ThreadPoolWorkQueue.Dispatch () [0x00074] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback () [0x00000] in <f32579baafc1404fa37ba3ec1abdc0bd>:0

Cheers,
Elco

[mauroa]

This has already been addressed in the recent commits and it will be available in the next release coming soon. Closing this issue.