def fetch(self, request, callback, **kwargs): if not isinstance(request, HTTPRequest): request = HTTPRequest(url=request, **kwargs) if not isinstance(request.headers, HTTPHeaders): request.headers = HTTPHeaders(request.headers) callback = stack_context.wrap(callback) self.queue.append((request, callback)) self._process_queue() if self.queue: logging.debug("max_clients limit reached, request queued. " "%d active, %d queued requests." % (len(self.active), len(self.queue)))