Add support for LB config in service config

4 files changed, 21 insertions, 12 deletions

diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
index dbb90b438c..dc0e1f89ce 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
@@ -123,7 +123,8 @@ class GrpcLb : public LoadBalancingPolicy {
  public:
   GrpcLb(const grpc_lb_addresses* addresses, const Args& args);
 
-  void UpdateLocked(const grpc_channel_args& args) override;
+  void UpdateLocked(const grpc_channel_args& args,
+                    grpc_json* lb_config) override;
   bool PickLocked(PickState* pick, grpc_error** error) override;
   void CancelPickLocked(PickState* pick, grpc_error* error) override;
   void CancelMatchingPicksLocked(uint32_t initial_metadata_flags_mask,
@@ -1331,7 +1332,7 @@ void GrpcLb::ProcessChannelArgsLocked(const grpc_channel_args& args) {
   grpc_channel_args_destroy(lb_channel_args);
 }
 
-void GrpcLb::UpdateLocked(const grpc_channel_args& args) {
+void GrpcLb::UpdateLocked(const grpc_channel_args& args, grpc_json* lb_config) {
   ProcessChannelArgsLocked(args);
   // Update the existing RR policy.
   if (rr_policy_ != nullptr) CreateOrUpdateRoundRobinPolicyLocked();
@@ -1727,7 +1728,7 @@ void GrpcLb::CreateOrUpdateRoundRobinPolicyLocked() {
       gpr_log(GPR_INFO, "[grpclb %p] Updating RR policy %p", this,
               rr_policy_.get());
     }
-    rr_policy_->UpdateLocked(*args);
+    rr_policy_->UpdateLocked(*args, nullptr);
   } else {
     LoadBalancingPolicy::Args lb_policy_args;
     lb_policy_args.combiner = combiner();
diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
index eb494486b9..d454401a66 100644
--- a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
@@ -46,7 +46,8 @@ class PickFirst : public LoadBalancingPolicy {
  public:
   explicit PickFirst(const Args& args);
 
-  void UpdateLocked(const grpc_channel_args& args) override;
+  void UpdateLocked(const grpc_channel_args& args,
+                    grpc_json* lb_config) override;
   bool PickLocked(PickState* pick, grpc_error** error) override;
   void CancelPickLocked(PickState* pick, grpc_error* error) override;
   void CancelMatchingPicksLocked(uint32_t initial_metadata_flags_mask,
@@ -159,7 +160,7 @@ PickFirst::PickFirst(const Args& args) : LoadBalancingPolicy(args) {
   if (grpc_lb_pick_first_trace.enabled()) {
     gpr_log(GPR_INFO, "Pick First %p created.", this);
   }
-  UpdateLocked(*args.args);
+  UpdateLocked(*args.args, args.lb_config);
   grpc_subchannel_index_ref();
 }
 
@@ -333,7 +334,8 @@ void PickFirst::UpdateChildRefsLocked() {
   child_subchannels_ = std::move(cs);
 }
 
-void PickFirst::UpdateLocked(const grpc_channel_args& args) {
+void PickFirst::UpdateLocked(const grpc_channel_args& args,
+                             grpc_json* lb_config) {
   AutoChildRefsUpdater guard(this);
   const grpc_arg* arg = grpc_channel_args_find(&args, GRPC_ARG_LB_ADDRESSES);
   if (arg == nullptr || arg->type != GRPC_ARG_POINTER) {
diff --git a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
index e9ed85cf66..2a16975131 100644
--- a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
@@ -57,7 +57,8 @@ class RoundRobin : public LoadBalancingPolicy {
  public:
   explicit RoundRobin(const Args& args);
 
-  void UpdateLocked(const grpc_channel_args& args) override;
+  void UpdateLocked(const grpc_channel_args& args,
+                    grpc_json* lb_config) override;
   bool PickLocked(PickState* pick, grpc_error** error) override;
   void CancelPickLocked(PickState* pick, grpc_error* error) override;
   void CancelMatchingPicksLocked(uint32_t initial_metadata_flags_mask,
@@ -232,7 +233,7 @@ RoundRobin::RoundRobin(const Args& args) : LoadBalancingPolicy(args) {
   gpr_mu_init(&child_refs_mu_);
   grpc_connectivity_state_init(&state_tracker_, GRPC_CHANNEL_IDLE,
                                "round_robin");
-  UpdateLocked(*args.args);
+  UpdateLocked(*args.args, args.lb_config);
   if (grpc_lb_round_robin_trace.enabled()) {
     gpr_log(GPR_INFO, "[RR %p] Created with %" PRIuPTR " subchannels", this,
             subchannel_list_->num_subchannels());
@@ -664,7 +665,8 @@ void RoundRobin::NotifyOnStateChangeLocked(grpc_connectivity_state* current,
                                                  notify);
 }
 
-void RoundRobin::UpdateLocked(const grpc_channel_args& args) {
+void RoundRobin::UpdateLocked(const grpc_channel_args& args,
+                              grpc_json* lb_config) {
   const grpc_arg* arg = grpc_channel_args_find(&args, GRPC_ARG_LB_ADDRESSES);
   AutoChildRefsUpdater guard(this);
   if (GPR_UNLIKELY(arg == nullptr || arg->type != GRPC_ARG_POINTER)) {
diff --git a/src/core/ext/filters/client_channel/lb_policy/xds/xds.cc b/src/core/ext/filters/client_channel/lb_policy/xds/xds.cc
index 59d57295d4..29cd904375 100644
--- a/src/core/ext/filters/client_channel/lb_policy/xds/xds.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/xds/xds.cc
@@ -118,7 +118,8 @@ class XdsLb : public LoadBalancingPolicy {
  public:
   XdsLb(const grpc_lb_addresses* addresses, const Args& args);
 
-  void UpdateLocked(const grpc_channel_args& args) override;
+  void UpdateLocked(const grpc_channel_args& args,
+                    grpc_json* lb_config) override;
   bool PickLocked(PickState* pick, grpc_error** error) override;
   void CancelPickLocked(PickState* pick, grpc_error* error) override;
   void CancelMatchingPicksLocked(uint32_t initial_metadata_flags_mask,
@@ -1010,6 +1011,7 @@ grpc_channel_args* BuildBalancerChannelArgs(
 // ctor and dtor
 //
 
+// TODO(vishalpowar): Use lb_config in args to configure LB policy.
 XdsLb::XdsLb(const grpc_lb_addresses* addresses,
              const LoadBalancingPolicy::Args& args)
     : LoadBalancingPolicy(args),
@@ -1314,7 +1316,8 @@ void XdsLb::ProcessChannelArgsLocked(const grpc_channel_args& args) {
   grpc_channel_args_destroy(lb_channel_args);
 }
 
-void XdsLb::UpdateLocked(const grpc_channel_args& args) {
+// TODO(vishalpowar): Use lb_config to configure LB policy.
+void XdsLb::UpdateLocked(const grpc_channel_args& args, grpc_json* lb_config) {
   ProcessChannelArgsLocked(args);
   // Update the existing child policy.
   // Note: We have disabled fallback mode in the code, so this child policy must
@@ -1672,7 +1675,8 @@ void XdsLb::CreateOrUpdateChildPolicyLocked() {
       gpr_log(GPR_INFO, "[xdslb %p] Updating the child policy %p", this,
               child_policy_.get());
     }
-    child_policy_->UpdateLocked(*args);
+    // TODO(vishalpowar): Pass the correct LB config.
+    child_policy_->UpdateLocked(*args, nullptr);
   } else {
     LoadBalancingPolicy::Args lb_policy_args;
     lb_policy_args.combiner = combiner();