| package kotlinx.coroutines.experimental |
| |
| import java.util.concurrent.ScheduledExecutorService |
| import java.util.concurrent.ScheduledThreadPoolExecutor |
| import java.util.concurrent.TimeUnit |
| import kotlin.coroutines.startCoroutine |
| |
| val KEEP_ALIVE = java.lang.Long.getLong("kotlinx.coroutines.ScheduledExecutor.keepAlive", 50L) |
| |
| internal val scheduledExecutor by lazy<ScheduledExecutorService> { |
| ScheduledThreadPoolExecutor(1) { r -> |
| Thread(r, "kotlinx.coroutines.ScheduledExecutor") |
| }.apply { |
| setKeepAliveTime(KEEP_ALIVE, TimeUnit.MILLISECONDS) |
| allowCoreThreadTimeOut(true) |
| // "setRemoveOnCancelPolicy" is available only since JDK7, so try it via reflection |
| try { |
| val m = this::class.java.getMethod("setRemoveOnCancelPolicy", Boolean::class.javaPrimitiveType) |
| m.invoke(this, true) |
| } catch (ex: Throwable) { /* ignore */ } |
| } |
| } |
| |
| /** |
| * Runs a given suspending block of code inside a coroutine with a specified timeout and throws |
| * [CancellationException] if timeout was exceeded. |
| */ |
| suspend fun <T> withTimeout(time: Long, unit: TimeUnit = TimeUnit.MILLISECONDS, block: suspend () -> T): T { |
| require(time >= 0) { "Timeout time $time cannot be negative" } |
| if (time <= 0L) throw CancellationException("Timed out immediately") |
| return suspendCancellableCoroutine { cont: CancellableContinuation<T> -> |
| // schedule cancellation of this continuation on time |
| val timeout = scheduledExecutor.schedule({ |
| // create an exception with a specific text |
| cont.cancel(CancellationException("Timed out waiting for $time $unit")) |
| }, time, unit) |
| cont.cancelFutureOnCompletion(timeout) |
| // restart block in a separate coroutine using cancellable context of this continuation, |
| block.startCoroutine(cont) |
| } |
| } |