Arrow Resilience Kit/com.sorinirmies.arrow.resiliencekit.stm/StmCounter

StmCounter

STM-based counter that can be atomically incremented/decremented.

Uses Arrow's Software Transactional Memory to provide lock-free, composable atomic operations on a counter value.

Basic usage:

val counter = StmCounter.create(0L)
atomically { with(counter) { increment() } }
println(counter.value()) // 1

Composing with other STM operations:

val counter = StmCounter.create(0L)
val gauge = StmGauge.create(0.0)

atomically {
    val count = with(counter) { increment() }
    with(gauge) { set(count.toDouble()) }
}

Batch updates inside a single transaction:

atomically {
    with(counter) {
        add(10)
        decrement()
    }
}
println(counter.value()) // 9

Types

Companion

object Companion

Factory for StmCounter.

Functions

add

fun STM.add(amount: Long): Long

Adds amount to the counter and returns the new value within an STM transaction.

current

fun STM.current(): Long

Reads the current counter value within an STM transaction.

decrement

fun STM.decrement(): Long

Decrements the counter by 1 and returns the new value within an STM transaction.

increment

fun STM.increment(): Long

Increments the counter by 1 and returns the new value within an STM transaction.

set

fun STM.set(value: Long)

Sets the counter to value within an STM transaction.

value

suspend fun value(): Long

Reads the current counter value by running an atomic transaction.