class Async::Scheduler

def close
	# It's critical to stop all tasks. Otherwise they might be holding on to resources which are never closed/released correctly.
	until self.terminate
		self.run_once!
	end
	
	Kernel.raise "Closing scheduler with blocked operations!" if @blocked > 0
	
	# We depend on GVL for consistency:
	# @guard.synchronize do
	
	# We want `@selector = nil` to be a visible side effect from this point forward, specifically in `#interrupt` and `#unblock`. If the selector is closed, then we don't want to push any fibers to it.
	selector = @selector
	@selector = nil
	
	selector&.close
	
	# end
	
	consume
end