Add re-resolution into LB policies

1 files changed, 19 insertions, 0 deletions

diff --git a/src/core/ext/filters/client_channel/lb_policy.h b/src/core/ext/filters/client_channel/lb_policy.h
index 72d027995a..d3159eebf3 100644
--- a/src/core/ext/filters/client_channel/lb_policy.h
+++ b/src/core/ext/filters/client_channel/lb_policy.h
@@ -38,6 +38,8 @@ struct grpc_lb_policy {
   grpc_pollset_set* interested_parties;
   /* combiner under which lb_policy actions take place */
   grpc_combiner* combiner;
+  /* callback to force a re-resolution */
+  grpc_closure* request_reresolution;
 };
 
 /** Extra arguments for an LB pick */
@@ -96,6 +98,11 @@ struct grpc_lb_policy_vtable {
 
   void (*update_locked)(grpc_exec_ctx* exec_ctx, grpc_lb_policy* policy,
                         const grpc_lb_policy_args* args);
+
+  /** \see grpc_lb_policy_set_reresolve_closure */
+  void (*set_reresolve_closure_locked)(grpc_exec_ctx* exec_ctx,
+                                       grpc_lb_policy* policy,
+                                       grpc_closure* request_reresolution);
 };
 
 #ifndef NDEBUG
@@ -202,4 +209,16 @@ void grpc_lb_policy_update_locked(grpc_exec_ctx* exec_ctx,
                                   grpc_lb_policy* policy,
                                   const grpc_lb_policy_args* lb_policy_args);
 
+/** Set the re-resolution closure to \a request_reresolution. */
+void grpc_lb_policy_set_reresolve_closure_locked(
+    grpc_exec_ctx* exec_ctx, grpc_lb_policy* policy,
+    grpc_closure* request_reresolution);
+
+/** Try to request a re-resolution. It's NOT a public API; it's only for use by
+    the LB policy implementations. */
+void grpc_lb_policy_try_reresolve(grpc_exec_ctx* exec_ctx,
+                                  grpc_lb_policy* policy,
+                                  grpc_core::TraceFlag* grpc_lb_trace,
+                                  grpc_error* error);
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_H */