CancellationTokenSource.Cancel throws System.ObjectDisposedException

[danielcweber]

We updated to version 12.6.0 and saw a large reduction in timeout exceptions with this and similar stack traces.

However, we started seeing a few that looked like this:

Message : The CancellationTokenSource has been disposed.
Exception type : System.ObjectDisposedException
Failed method: ExRam.Gremlinq.Providers.Core.WebSocketGremlinqClientFactory+WebSocketGremlinqClientFactoryImpl`1+WebSocketGremlinqClient.Dispose

Stack Trace:

System.ObjectDisposedException:
   at System.ThrowHelper.ThrowObjectDisposedException (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Threading.CancellationTokenSource.Cancel (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at ExRam.Gremlinq.Providers.Core.WebSocketGremlinqClientFactory+WebSocketGremlinqClientFactoryImpl`1+WebSocketGremlinqClient.Dispose (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null: /_/src/Providers.Core/Factory/WebSocketGremlinqClientFactory.cs:281)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientExtensions+ThrottledGremlinqClient.Dispose (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null: /_/src/Providers.Core/Extensions/GremlinqClientExtensions.cs:165)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientFactory+PoolGremlinqClientFactory`1+PoolGremlinqClient+PoolSlotGremlinqClient+<<SubmitAsync>g__Core|3_0>d`1.MoveNext (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null: /_/src/Providers.Core/Factory/GremlinqClientFactory.cs:58)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientFactory+PoolGremlinqClientFactory`1+PoolGremlinqClient+PoolSlotGremlinqClient+<<SubmitAsync>g__Core|3_0>d`1.MoveNext (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null: /_/src/Providers.Core/Factory/GremlinqClientFactory.cs:63)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Threading.Tasks.Sources.ManualResetValueTaskSourceCore`1.ThrowForFailedGetResult (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientFactory+PoolGremlinqClientFactory`1+PoolGremlinqClient+PoolSlotGremlinqClient+<<SubmitAsync>g__Core|3_0>d`1.System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientExtensions+RetryGremlinqClient+<<SubmitAsync>g__Core|3_0>d`1.MoveNext (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null: /_/src/Providers.Core/Extensions/GremlinqClientExtensions.cs:225)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientExtensions+RetryGremlinqClient+<<SubmitAsync>g__Core|3_0>d`1.MoveNext (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null: /_/src/Providers.Core/Extensions/GremlinqClientExtensions.cs:238)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Threading.Tasks.Sources.ManualResetValueTaskSourceCore`1.ThrowForFailedGetResult (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientExtensions+RetryGremlinqClient+<<SubmitAsync>g__Core|3_0>d`1.System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientFactory+PoolGremlinqClientFactory`1+PoolGremlinqClient+<<SubmitAsync>g__Core|9_0>d`1.MoveNext (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null: /_/src/Providers.Core/Factory/GremlinqClientFactory.cs:131)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientFactory+PoolGremlinqClientFactory`1+PoolGremlinqClient+<<SubmitAsync>g__Core|9_0>d`1.MoveNext (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null: /_/src/Providers.Core/Factory/GremlinqClientFactory.cs:131)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Threading.Tasks.Sources.ManualResetValueTaskSourceCore`1.ThrowForFailedGetResult (System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientFactory+PoolGremlinqClientFactory`1+PoolGremlinqClient+<<SubmitAsync>g__Core|9_0>d`1.System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null)
   at ExRam.Gremlinq.Providers.Core.GremlinqClientExtensions+LoggingGremlinqClient+<<SubmitAsync>g__Core|6_0>d`1.MoveNext (ExRam.Gremlinq.Providers.Core, Version=12.6.0.0, Culture=neutral, PublicKeyToken=null: /_/src/Providers.Core/Extensions/GremlinqClientExtensions.cs:100) 

Originally posted by @bobvaselaarchs in #1488 (comment)

[danielcweber]

Fixed by #1545 .