Bug in `IntervalList` causes leak in locks.

[lukebakken]

Describe the bug

Reported here:
#1751 (comment)

Reproduction steps

Not provided.

Expected behavior

MonitorHeld metric does not increase.

Additional context

#1751

[lukebakken]

@DenisMayorko - do you see the same symptoms as initially reported in this issue - what appears to be a deadlock in CloseAsync? My guess is yes based on the output you provided but I'd like to be sure.

[DenisMayorko]

@DenisMayorko - do you see the same symptoms as initially reported in this issue - what appears to be a deadlock in CloseAsync? My guess is yes based on the output you provided but I'd like to be sure.

Hmm… I see a large number of ShutdownEvent and a corresponding deadlock, an increase in the number of timers, etc., but I don’t see any mentions of Close or Dispose methods in the StackTrace. I’m starting to doubt that the issues are related, although the problem also seems to occur when shutting down the channel, judging by the call stack.

I also see a large number of the following dumpasync outputs; in the version after the changes, they are significantly fewer.

<< Awaiting: 00007e21d0837818 00007f2a0d6c0018 System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable<System.Boolean>+ConfiguredValueTaskAwaiter >>
  00007e21d08376f0 00007f2a0db9ca88 (6) RabbitMQ.Client.ConsumerDispatching.AsyncConsumerDispatcher+<ProcessChannelAsync>d__1
    00007e21cda354c8 00007f2a0db70800 ( ) System.Threading.Tasks.UnwrapPromise<System.Threading.Tasks.VoidTaskResult>

[lukebakken]

@DenisMayorko - please give version 7.1.1-alpha.0 a test in your environment. It's available here:

https://www.myget.org/feed/rabbitmq-dotnet-client/package/nuget/RabbitMQ.Client

[lukebakken]

This issue will be fixed for good by #1790