https://learn.microsoft.com/en-us/dotnet/api/system.threading.readerwriterlock.isreaderlockheld?view=netframework-4.8.1&viewFallbackFrom=net-10.0
ReaderWriterLock.IsReaderLockHeld Property (System.Threading) | Microsoft Learn
Gets a value indicating whether the current thread holds a reader lock.
property systemthreadingmicrosoftlearn