delay + cancelled runBlocking shutdown loop

[adamp]

The following code will enter an infinite loop in ThreadEventLoop.shutdown():

runBlocking {
	coroutineContext.cancel()
	delay(1)
}

This loop does not make progress (EventLoop.kt line 337):

// complete processing of all queued tasks
while (processNextEvent() <= 0) { /* spin */ }
// reschedule the rest of delayed tasks
rescheduleAllDelayed()

The heap in EventLoopBase._delayed is not empty and EventLoopBasel._queued was set to CLOSED_EMPTY. isCompleted is true. enqueueImpl(it) on line 133 of EventLoop.kt cannot move the delay into _queued, therefore dequeue()?.run() does nothing. However nextTime is calculated as 0 and returned as a result of checking _delayed.value.peek(), which still exists, causing the loop in shutdown to continue.