CancellableContinuation.invokeOnCancellation should accept a suspend callback about kotlinx.coroutines HOT 16 OPEN

suspend fun waitForEvent(): Unit = suspendCancellableCoroutine { continuation ->
  setWaitForEventCallback { continuation.resume(Unit) }
  continuation.invokeOnCancellation {
    runBlocking { clearWaitForEventCallback().await() } // Block the thread that cancels.
  }
}

val cancellationLock = Mutex(false)
suspend fun waitForEvent() {
  lock.withLock {} // Wait for previous cancellation.
  suspendCancellableCoroutine { continuation ->
    setWaitForEventCallback { continuation.resume(Unit) }
    cancellationLock.lock() // Lock only after setWaitForEventCallback.
    continuation.invokeOnCancellation {
      clearWaitForEventCallback().addListener({ cancellationLock.tryUnlock() }, <Executor not from this Job, which may have been cancelled>)
    }
  }
  cancellationLock.tryUnlock() // Finished successfully.
}

fun Mutex.tryUnlock() {
  try { lock.unlick() }
  catch (e: IllegalStateException) {}
}