--- /dev/null
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_BACKUP_POLLER_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_BACKUP_POLLER_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/grpc.h>
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/gprpp/global_config.h"
+
+GPR_GLOBAL_CONFIG_DECLARE_INT32(grpc_client_channel_backup_poll_interval_ms);
+
+/* Initializes backup polling. */
+void grpc_client_channel_global_init_backup_polling();
+
+/* Starts polling \a interested_parties periodically in the timer thread. */
+void grpc_client_channel_start_backup_polling(
+ grpc_pollset_set* interested_parties);
+
+/* Stops polling \a interested_parties. */
+void grpc_client_channel_stop_backup_polling(
+ grpc_pollset_set* interested_parties);
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_BACKUP_POLLER_H */