class Async::Scheduler

@yields {|duration| ...} The block to execute with a timeout.
@parameter message [String] The message to pass to the exception.
@parameter exception [Class] The exception class to raise.
@parameter duration [Numeric] The time in seconds, in which the task should complete.

@asynchronous May raise an exception at any interruption point (e.g. blocking operations).
@public Since *Async v1*.

Invoke the block, but after the specified timeout, raise {TimeoutError} in any currenly blocking operation. If the block runs to completion before the timeout occurs or there are no non-blocking operations after the timeout expires, the code will complete without any exception.

def with_timeout(duration, exception = TimeoutError, message = "execution expired", &block)
	fiber = Fiber.current
	
	timer = @timers.after(duration) do
		if fiber.alive?
			fiber.raise(exception, message)
		end
	end
	
	yield timer
ensure
	timer&.cancel!
end