module Kernel

def Sync(annotation: nil, &block)

@asynchronous Will block until given block completes executing.
@public Since *Async v1*.

@parameter task [Async::Task] The task that is executing the given block.
@yields {|task| ...} The block that will execute asynchronously.

Run the given block of code synchronously, but within a reactor if not already in one. 
def Sync(annotation: nil, &block)
	if task = ::Async::Task.current?
		if annotation
			task.annotate(annotation) {yield task}
		else
			yield task
		end
	elsif scheduler = Fiber.scheduler
		::Async::Task.run(scheduler, &block).wait
	else
		# This calls Fiber.set_scheduler(self):
		reactor = Async::Reactor.new
		
		begin
			# Use finished: false to suppress warnings since we're handling exceptions explicitly
			task = reactor.async(annotation: annotation, finished: false, &block)
			reactor.run
			return task.wait
		ensure
			Fiber.set_scheduler(nil)
		end
	end
end