Tornado Long-Polling Example

tornado-long-polling.py

import tornado.ioloop
import tornado.web
import time

class MainHandler(tornado.web.RequestHandler):
	@tornado.web.asynchronous
	def get(self, request):
		if request is None:
			self.application.go = False
			self.write("Waiting for GET @ http://localhost:8888/go...<br>")
			self.flush()
			self._do_wait()
		else:
			self.application.go = True
			self.finish('Thanks!')
	
	def _do_wait(self, timeout_trys=10):
		if self.application.go:
			self.write('Finish')
			self.finish()
		else:
			self.write("Sleeping 2 second, timeout_trys=%s<br>" % timeout_trys)
			self.flush()
			tornado.ioloop.IOLoop.instance().add_timeout(time.time() + 2, 
				lambda: self._do_wait(timeout_trys-1))
			

application = tornado.web.Application([
	(r"/(\w+)?", MainHandler),
])

if __name__ == "__main__":
	application.listen(8888)
	tornado.ioloop.IOLoop.instance().start()

Copied from http://tornadogists.org/2185380/