Sometimes there is the need to cancel the execution of a coroutine after a given period of time. You can do this manually by combining the
delay() and cancel() functions. However, this technique is verbose and error-prone. An easier way to manage timeouts is
using the function withTimeout() or withTimeoutOrNull().
The withTimeout function will throw a TimeoutCancellationException when the timeout is reached, while
withTimeoutOrNull will simply return null instead.
This rule raises an issue if timeout mechanisms are implemented manually instead of using appropriate built-in functions.
Noncompliant code example
suspend fun main() {
coroutineScope {
val job = launch {
delay(2000L)
println("Finished")
}
delay(500L)
job.cancel()
}
}
Compliant solution
suspend fun main() {
coroutineScope {
withTimeoutOrNull(1000L){
delay(2000L)
println("Finished")
}
}
}
