compareAndSwap
Platform and version requirements: Native (1.3) 
fun compareAndSwap(expected: T, new: T): T
Compares value with expected and replaces it with new value if values matches. If new value is not null and object is frozen, it must be frozen or permanent object.
Parameters
 expected - the expected value
 new - the new value
Exceptions
 InvalidMutabilityException - if the value is not frozen or a permanent object
Return the old value
    © 2010–2021 JetBrains s.r.o. and Kotlin Programming Language contributors
Licensed under the Apache License, Version 2.0.
    https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.native.concurrent/-freezable-atomic-reference/compare-and-swap.html