| package kotlinx.coroutines.experimental |
| |
| import kotlin.coroutines.experimental.CoroutineContext |
| |
| |
| /** |
| * Helper function for coroutine builder implementations to handle uncaught exception in coroutines. |
| * It tries to handle uncaught exception in the following way: |
| * * If there is [CoroutineExceptionHandler] in the context, then it is used. |
| * * Otherwise, if exception is [CancellationException] then it is ignored |
| * (because that is the supposed mechanism to cancel the running coroutine) |
| * * Otherwise, if there is a [Job] in the context, then [Job.cancel] is invoked and if it |
| * returns `true` (it was still active), then the exception is considered to be handled. |
| * * Otherwise, current thread's [Thread.uncaughtExceptionHandler] is used. |
| */ |
| fun handleCoroutineException(context: CoroutineContext, exception: Throwable) { |
| context[CoroutineExceptionHandler]?.let { |
| it.handleException(context, exception) |
| return |
| } |
| // ignore CancellationException (they are normal means to terminate a coroutine) |
| if (exception is CancellationException) return |
| // quit if successfully pushed exception as cancellation reason |
| if (context[Job]?.cancel(exception) ?: false) return |
| // otherwise just use thread's handler |
| val currentThread = Thread.currentThread() |
| currentThread.uncaughtExceptionHandler.uncaughtException(currentThread, exception) |
| } |
| |
| /** |
| * An optional element on the coroutine context to handler uncaught exceptions. |
| * See [handleCoroutineException]. |
| */ |
| public interface CoroutineExceptionHandler : CoroutineContext.Element { |
| companion object Key : CoroutineContext.Key<CoroutineExceptionHandler> |
| public fun handleException(context: CoroutineContext, exception: Throwable) |
| } |