decrementAndFetch  
  Atomically decrements the current value of this AtomicInt by one and returns the new value.
Since Kotlin
2.1Samples
import kotlin.concurrent.atomics.*
import kotlin.concurrent.thread
fun main() { 
   //sampleStart 
   val a = AtomicInt(7)
println(a.decrementAndFetch()) // 6
println(a.load()) // 6 
   //sampleEnd
}Atomically decrements the current value of this AtomicLong by one and returns the new value.
Since Kotlin
2.1Samples
import kotlin.concurrent.atomics.*
import kotlin.concurrent.thread
fun main() { 
   //sampleStart 
   val a = AtomicLong(7)
println(a.decrementAndFetch()) // 6
println(a.load()) // 6 
   //sampleEnd
}