Add GPR_UNLIKELY annotations mainly for the client path in error conditions

2 files changed, 13 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 1a675476f0..ec338fbeac 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
@@ -398,7 +398,7 @@ grpc_lb_addresses* ExtractBackendAddresses(const grpc_lb_addresses* addresses) {
 bool IsServerValid(const grpc_grpclb_server* server, size_t idx, bool log) {
   if (server->drop) return false;
   const grpc_grpclb_ip_address* ip = &server->ip_address;
-  if (server->port >> 16 != 0) {
+  if (GPR_UNLIKELY(server->port >> 16 != 0)) {
     if (log) {
       gpr_log(GPR_ERROR,
               "Invalid port '%d' at index %lu of serverlist. Ignoring.",
@@ -406,7 +406,7 @@ bool IsServerValid(const grpc_grpclb_server* server, size_t idx, bool log) {
     }
     return false;
   }
-  if (ip->size != 4 && ip->size != 16) {
+  if (GPR_UNLIKELY(ip->size != 4 && ip->size != 16)) {
     if (log) {
       gpr_log(GPR_ERROR,
               "Expected IP to be 4 or 16 bytes, got %d at index %lu of "
@@ -714,7 +714,7 @@ void GrpcLb::BalancerCallState::SendClientLoadReportLocked() {
                     this, grpc_combiner_scheduler(grpclb_policy()->combiner()));
   grpc_call_error call_error = grpc_call_start_batch_and_execute(
       lb_call_, &op, 1, &client_load_report_closure_);
-  if (call_error != GRPC_CALL_OK) {
+  if (GPR_UNLIKELY(call_error != GRPC_CALL_OK)) {
     gpr_log(GPR_ERROR, "[grpclb %p] call_error=%d", grpclb_policy_.get(),
             call_error);
     GPR_ASSERT(GRPC_CALL_OK == call_error);
@@ -936,7 +936,7 @@ grpc_lb_addresses* ExtractBalancerAddresses(
   size_t lb_addresses_idx = 0;
   for (size_t i = 0; i < addresses->num_addresses; ++i) {
     if (!addresses->addresses[i].is_balancer) continue;
-    if (addresses->addresses[i].user_data != nullptr) {
+    if (GPR_UNLIKELY(addresses->addresses[i].user_data != nullptr)) {
       gpr_log(GPR_ERROR,
               "This LB policy doesn't support user data. It will be ignored");
     }
@@ -1284,7 +1284,7 @@ void GrpcLb::NotifyOnStateChangeLocked(grpc_connectivity_state* current,
 
 void GrpcLb::ProcessChannelArgsLocked(const grpc_channel_args& args) {
   const grpc_arg* arg = grpc_channel_args_find(&args, GRPC_ARG_LB_ADDRESSES);
-  if (arg == nullptr || arg->type != GRPC_ARG_POINTER) {
+  if (GPR_UNLIKELY(arg == nullptr || arg->type != GRPC_ARG_POINTER)) {
     // Ignore this update.
     gpr_log(
         GPR_ERROR,
@@ -1520,7 +1520,7 @@ void GrpcLb::PendingPickSetMetadataAndContext(PendingPick* pp) {
    * policy (e.g., all addresses failed to connect). There won't be any
    * user_data/token available */
   if (pp->pick->connected_subchannel != nullptr) {
-    if (!GRPC_MDISNULL(pp->lb_token)) {
+    if (GPR_LIKELY(!GRPC_MDISNULL(pp->lb_token))) {
       AddLbTokenToInitialMetadata(GRPC_MDELEM_REF(pp->lb_token),
                                   &pp->pick->lb_token_mdelem_storage,
                                   pp->pick->initial_metadata);
@@ -1645,7 +1645,7 @@ void GrpcLb::CreateRoundRobinPolicyLocked(const Args& args) {
   GPR_ASSERT(rr_policy_ == nullptr);
   rr_policy_ = LoadBalancingPolicyRegistry::CreateLoadBalancingPolicy(
       "round_robin", args);
-  if (rr_policy_ == nullptr) {
+  if (GPR_UNLIKELY(rr_policy_ == nullptr)) {
     gpr_log(GPR_ERROR, "[grpclb %p] Failure creating a RoundRobin policy",
             this);
     return;
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc
index 7ef3bcf24f..0e80dd5521 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc
@@ -29,7 +29,7 @@ static bool count_serverlist(pb_istream_t* stream, const pb_field_t* field,
                              void** arg) {
   grpc_grpclb_serverlist* sl = static_cast<grpc_grpclb_serverlist*>(*arg);
   grpc_grpclb_server server;
-  if (!pb_decode(stream, grpc_lb_v1_Server_fields, &server)) {
+  if (GPR_UNLIKELY(!pb_decode(stream, grpc_lb_v1_Server_fields, &server))) {
     gpr_log(GPR_ERROR, "nanopb error: %s", PB_GET_ERROR(stream));
     return false;
   }
@@ -52,7 +52,7 @@ static bool decode_serverlist(pb_istream_t* stream, const pb_field_t* field,
   GPR_ASSERT(dec_arg->serverlist->num_servers >= dec_arg->decoding_idx);
   grpc_grpclb_server* server =
       static_cast<grpc_grpclb_server*>(gpr_zalloc(sizeof(grpc_grpclb_server)));
-  if (!pb_decode(stream, grpc_lb_v1_Server_fields, server)) {
+  if (GPR_UNLIKELY(!pb_decode(stream, grpc_lb_v1_Server_fields, server))) {
     gpr_free(server);
     gpr_log(GPR_ERROR, "nanopb error: %s", PB_GET_ERROR(stream));
     return false;
@@ -165,7 +165,8 @@ grpc_grpclb_initial_response* grpc_grpclb_initial_response_parse(
                              GRPC_SLICE_LENGTH(encoded_grpc_grpclb_response));
   grpc_grpclb_response res;
   memset(&res, 0, sizeof(grpc_grpclb_response));
-  if (!pb_decode(&stream, grpc_lb_v1_LoadBalanceResponse_fields, &res)) {
+  if (GPR_UNLIKELY(
+          !pb_decode(&stream, grpc_lb_v1_LoadBalanceResponse_fields, &res))) {
     gpr_log(GPR_ERROR, "nanopb error: %s", PB_GET_ERROR(&stream));
     return nullptr;
   }
@@ -195,7 +196,7 @@ grpc_grpclb_serverlist* grpc_grpclb_response_parse_serverlist(
   res.server_list.servers.funcs.decode = count_serverlist;
   res.server_list.servers.arg = sl;
   bool status = pb_decode(&stream, grpc_lb_v1_LoadBalanceResponse_fields, &res);
-  if (!status) {
+  if (GPR_UNLIKELY(!status)) {
     gpr_free(sl);
     gpr_log(GPR_ERROR, "nanopb error: %s", PB_GET_ERROR(&stream));
     return nullptr;
@@ -211,7 +212,7 @@ grpc_grpclb_serverlist* grpc_grpclb_response_parse_serverlist(
     res.server_list.servers.arg = &decode_arg;
     status = pb_decode(&stream_at_start, grpc_lb_v1_LoadBalanceResponse_fields,
                        &res);
-    if (!status) {
+    if (GPR_UNLIKELY(!status)) {
       grpc_grpclb_destroy_serverlist(sl);
       gpr_log(GPR_ERROR, "nanopb error: %s", PB_GET_ERROR(&stream));
       return nullptr;