Retry with exponential back off coroutines

RetryCoroutines.kt

import kotlinx.coroutines.*
import java.io.IOException

suspend fun <T> retryIO(
    times: Int = Int.MAX_VALUE,
    initialDelay: Long = 100, // 0.1 second
    maxDelay: Long = 1000,    // 1 second
    factor: Double = 2.0,
    block: suspend () -> T
): T {
    var currentDelay = initialDelay
    repeat(times - 1) {
        try {
            return block()
        } catch (e: IOException) {
            println("Retrying due to: ${e.message}")
        }
        delay(currentDelay)
        currentDelay = (currentDelay * factor).toLong().coerceAtMost(maxDelay)
    }
    return block() // last attempt
}

fun main() = runBlocking<Unit> {

    try {
    	val result = retryIO(times = 5) {
        getResult()
    	}
    	println("Final result: $result")
    } catch(ex: Exception) {
        println("All tries failed due to: ${ex.message}")
    }
}

suspend fun getResult(): String {
    //throw IOException("Simulated IO exception")
    return "Success"
}