Add GPR_UNLIKELY annotations mainly for the client path in error conditions

src/core/ext/filters/client_channel/backup_poller.cc

@@ -61,7 +61,7 @@ static void init_globals() {
   char* env = gpr_getenv("GRPC_CLIENT_CHANNEL_BACKUP_POLL_INTERVAL_MS");
   if (env != nullptr) {
     int poll_interval_ms = gpr_parse_nonnegative_int(env);
-    if (poll_interval_ms == -1) {
+    if (GPR_UNLIKELY(poll_interval_ms == -1)) {
       gpr_log(GPR_ERROR,
               "Invalid GRPC_CLIENT_CHANNEL_BACKUP_POLL_INTERVAL_MS: %s, "
               "default value %d will be used.",

src/core/ext/filters/client_channel/channel_connectivity.cc

@@ -40,7 +40,7 @@ grpc_connectivity_state grpc_channel_check_connectivity_state(
   GRPC_API_TRACE(
       "grpc_channel_check_connectivity_state(channel=%p, try_to_connect=%d)", 2,
       (channel, try_to_connect));
-  if (client_channel_elem->filter == &grpc_client_channel_filter) {
+  if (GPR_LIKELY(client_channel_elem->filter == &grpc_client_channel_filter)) {
     state = grpc_client_channel_check_connectivity_state(client_channel_elem,
                                                          try_to_connect);
 

src/core/ext/filters/client_channel/client_channel.cc

@@ -379,7 +379,7 @@ static void on_resolver_result_changed_locked(void* arg, grpc_error* error) {
         new_lb_policy =
             grpc_core::LoadBalancingPolicyRegistry::CreateLoadBalancingPolicy(
                 lb_policy_name, lb_policy_args);
-        if (new_lb_policy == nullptr) {
+        if (GPR_UNLIKELY(new_lb_policy == nullptr)) {
           gpr_log(GPR_ERROR, "could not create LB policy \"%s\"",
                   lb_policy_name);
         } else {
@@ -2200,7 +2200,7 @@ static void add_retriable_send_initial_metadata_op(
         &batch_data->send_initial_metadata_storage[calld->send_initial_metadata
                                                        .list.count],
         retry_md);
-    if (error != GRPC_ERROR_NONE) {
+    if (GPR_UNLIKELY(error != GRPC_ERROR_NONE)) {
       gpr_log(GPR_ERROR, "error adding retry metadata: %s",
               grpc_error_string(error));
       GPR_ASSERT(false);

src/core/ext/filters/client_channel/http_connect_handshaker.cc

@@ -280,7 +280,7 @@ static void http_connect_handshaker_do_handshake(
         gpr_malloc(sizeof(grpc_http_header) * num_header_strings));
     for (size_t i = 0; i < num_header_strings; ++i) {
       char* sep = strchr(header_strings[i], ':');
-      if (sep == nullptr) {
+      if (GPR_UNLIKELY(sep == nullptr)) {
         gpr_log(GPR_ERROR, "skipping unparseable HTTP CONNECT header: %s",
                 header_strings[i]);
         continue;

src/core/ext/filters/client_channel/http_proxy.cc

@@ -50,11 +50,11 @@ static char* get_http_proxy_server(char** user_cred) {
   size_t authority_nstrs;
   if (uri_str == nullptr) return nullptr;
   grpc_uri* uri = grpc_uri_parse(uri_str, false /* suppress_errors */);
-  if (uri == nullptr || uri->authority == nullptr) {
+  if (GPR_UNLIKELY(uri == nullptr || uri->authority == nullptr)) {
     gpr_log(GPR_ERROR, "cannot parse value of 'http_proxy' env var");
     goto done;
   }
-  if (strcmp(uri->scheme, "http") != 0) {
+  if (GPR_UNLIKELY(strcmp(uri->scheme, "http") != 0)) {
     gpr_log(GPR_ERROR, "'%s' scheme not supported in proxy URI", uri->scheme);
     goto done;
   }
@@ -93,7 +93,7 @@ static bool proxy_mapper_map_name(grpc_proxy_mapper* mapper,
   if (*name_to_resolve == nullptr) return false;
   char* no_proxy_str = nullptr;
   grpc_uri* uri = grpc_uri_parse(server_uri, false /* suppress_errors */);
-  if (uri == nullptr || uri->path[0] == '\0') {
+  if (GPR_UNLIKELY(uri == nullptr || uri->path[0] == '\0')) {
     gpr_log(GPR_ERROR,
             "'http_proxy' environment variable set, but cannot "
             "parse server URI '%s' -- not using proxy",

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;

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;

src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc

@@ -608,7 +608,7 @@ void RoundRobin::PingOneLocked(grpc_closure* on_initiate,
 
 void RoundRobin::UpdateLocked(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)) {
     gpr_log(GPR_ERROR, "[RR %p] update provided no addresses; ignoring", this);
     // If we don't have a current subchannel list, go into TRANSIENT_FAILURE.
     // Otherwise, keep using the current subchannel list (ignore this update).

src/core/ext/filters/client_channel/parse_address.cc

@@ -39,7 +39,7 @@
 
 bool grpc_parse_unix(const grpc_uri* uri,
                      grpc_resolved_address* resolved_addr) {
-  if (strcmp("unix", uri->scheme) != 0) {
+  if (GPR_UNLIKELY(strcmp("unix", uri->scheme) != 0)) {
     gpr_log(GPR_ERROR, "Expected 'unix' scheme, got '%s'", uri->scheme);
     return false;
   }
@@ -75,17 +75,18 @@ bool grpc_parse_ipv4_hostport(const char* hostport, grpc_resolved_address* addr,
   addr->len = static_cast<socklen_t>(sizeof(grpc_sockaddr_in));
   grpc_sockaddr_in* in = reinterpret_cast<grpc_sockaddr_in*>(addr->addr);
   in->sin_family = GRPC_AF_INET;
-  if (grpc_inet_pton(GRPC_AF_INET, host, &in->sin_addr) == 0) {
+  if (GPR_UNLIKELY(grpc_inet_pton(GRPC_AF_INET, host, &in->sin_addr) == 0)) {
     if (log_errors) gpr_log(GPR_ERROR, "invalid ipv4 address: '%s'", host);
     goto done;
   }
   // Parse port.
-  if (port == nullptr) {
+  if (GPR_UNLIKELY(port == nullptr)) {
     if (log_errors) gpr_log(GPR_ERROR, "no port given for ipv4 scheme");
     goto done;
   }
   int port_num;
-  if (sscanf(port, "%d", &port_num) != 1 || port_num < 0 || port_num > 65535) {
+  if (GPR_UNLIKELY(sscanf(port, "%d", &port_num) != 1 || port_num < 0 ||
+                   port_num > 65535)) {
     if (log_errors) gpr_log(GPR_ERROR, "invalid ipv4 port: '%s'", port);
     goto done;
   }
@@ -99,7 +100,7 @@ done:
 
 bool grpc_parse_ipv4(const grpc_uri* uri,
                      grpc_resolved_address* resolved_addr) {
-  if (strcmp("ipv4", uri->scheme) != 0) {
+  if (GPR_UNLIKELY(strcmp("ipv4", uri->scheme) != 0)) {
     gpr_log(GPR_ERROR, "Expected 'ipv4' scheme, got '%s'", uri->scheme);
     return false;
   }
@@ -130,32 +131,35 @@ bool grpc_parse_ipv6_hostport(const char* hostport, grpc_resolved_address* addr,
     uint32_t sin6_scope_id = 0;
     strncpy(host_without_scope, host, host_without_scope_len);
     host_without_scope[host_without_scope_len] = '\0';
-    if (grpc_inet_pton(GRPC_AF_INET6, host_without_scope, &in6->sin6_addr) ==
-        0) {
+    if (GPR_UNLIKELY(grpc_inet_pton(GRPC_AF_INET6, host_without_scope,
+                                    &in6->sin6_addr)) == 0) {
       gpr_log(GPR_ERROR, "invalid ipv6 address: '%s'", host_without_scope);
       goto done;
     }
-    if (gpr_parse_bytes_to_uint32(host_end + 1,
+    if (GPR_UNLIKELY(
+            gpr_parse_bytes_to_uint32(host_end + 1,
                                       strlen(host) - host_without_scope_len - 1,
-                                  &sin6_scope_id) == 0) {
+                                      &sin6_scope_id) == 0)) {
       gpr_log(GPR_ERROR, "invalid ipv6 scope id: '%s'", host_end + 1);
       goto done;
     }
     // Handle "sin6_scope_id" being type "u_long". See grpc issue #10027.
     in6->sin6_scope_id = sin6_scope_id;
   } else {
-    if (grpc_inet_pton(GRPC_AF_INET6, host, &in6->sin6_addr) == 0) {
+    if (GPR_UNLIKELY(grpc_inet_pton(GRPC_AF_INET6, host, &in6->sin6_addr) ==
+                     0)) {
       gpr_log(GPR_ERROR, "invalid ipv6 address: '%s'", host);
       goto done;
     }
   }
   // Parse port.
-  if (port == nullptr) {
+  if (GPR_UNLIKELY(port == nullptr)) {
     if (log_errors) gpr_log(GPR_ERROR, "no port given for ipv6 scheme");
     goto done;
   }
   int port_num;
-  if (sscanf(port, "%d", &port_num) != 1 || port_num < 0 || port_num > 65535) {
+  if (GPR_UNLIKELY(sscanf(port, "%d", &port_num) != 1 || port_num < 0 ||
+                   port_num > 65535)) {
     if (log_errors) gpr_log(GPR_ERROR, "invalid ipv6 port: '%s'", port);
     goto done;
   }
@@ -169,7 +173,7 @@ done:
 
 bool grpc_parse_ipv6(const grpc_uri* uri,
                      grpc_resolved_address* resolved_addr) {
-  if (strcmp("ipv6", uri->scheme) != 0) {
+  if (GPR_UNLIKELY(strcmp("ipv6", uri->scheme) != 0)) {
     gpr_log(GPR_ERROR, "Expected 'ipv6' scheme, got '%s'", uri->scheme);
     return false;
   }

src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc

@@ -225,14 +225,15 @@ bool ValueInJsonArray(grpc_json* array, const char* value) {
 
 char* ChooseServiceConfig(char* service_config_choice_json) {
   grpc_json* choices_json = grpc_json_parse_string(service_config_choice_json);
-  if (choices_json == nullptr || choices_json->type != GRPC_JSON_ARRAY) {
+  if (GPR_UNLIKELY(choices_json == nullptr ||
+                   choices_json->type != GRPC_JSON_ARRAY)) {
     gpr_log(GPR_ERROR, "cannot parse service config JSON string");
     return nullptr;
   }
   char* service_config = nullptr;
   for (grpc_json* choice = choices_json->child; choice != nullptr;
        choice = choice->next) {
-    if (choice->type != GRPC_JSON_OBJECT) {
+    if (GPR_UNLIKELY(choice->type != GRPC_JSON_OBJECT)) {
       gpr_log(GPR_ERROR, "cannot parse service config JSON string");
       break;
     }

src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc

@@ -310,7 +310,7 @@ class NativeDnsResolverFactory : public ResolverFactory {
  public:
   OrphanablePtr<Resolver> CreateResolver(
       const ResolverArgs& args) const override {
-    if (0 != strcmp(args.uri->authority, "")) {
+    if (GPR_UNLIKELY(0 != strcmp(args.uri->authority, ""))) {
       gpr_log(GPR_ERROR, "authority based dns uri's not supported");
       return OrphanablePtr<Resolver>(nullptr);
     }

src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc

@@ -123,7 +123,7 @@ void DoNothing(void* ignored) {}
 OrphanablePtr<Resolver> CreateSockaddrResolver(
     const ResolverArgs& args,
     bool parse(const grpc_uri* uri, grpc_resolved_address* dst)) {
-  if (0 != strcmp(args.uri->authority, "")) {
+  if (GPR_UNLIKELY(0 != strcmp(args.uri->authority, ""))) {
     gpr_log(GPR_ERROR, "authority-based URIs not supported by the %s scheme",
             args.uri->scheme);
     return OrphanablePtr<Resolver>(nullptr);

src/core/ext/filters/client_channel/resolver_registry.cc

@@ -74,7 +74,7 @@ class RegistryState {
       *uri = grpc_uri_parse(*canonical_target, 1);
       factory =
           *uri == nullptr ? nullptr : LookupResolverFactory((*uri)->scheme);
-      if (factory == nullptr) {
+      if (GPR_UNLIKELY(factory == nullptr)) {
         grpc_uri_destroy(grpc_uri_parse(target, 0));
         grpc_uri_destroy(grpc_uri_parse(*canonical_target, 0));
         gpr_log(GPR_ERROR, "don't know how to resolve '%s' or '%s'", target,

src/core/ext/filters/client_channel/subchannel.cc

@@ -577,7 +577,7 @@ static bool publish_transport_locked(grpc_subchannel* c) {
   grpc_error* error = grpc_channel_stack_builder_finish(
       builder, 0, 1, connection_destroy, nullptr,
       reinterpret_cast<void**>(&stk));
-  if (error != GRPC_ERROR_NONE) {
+  if (GPR_UNLIKELY(error != GRPC_ERROR_NONE)) {
     grpc_transport_destroy(c->connecting_result.transport);
     gpr_log(GPR_ERROR, "error initializing subchannel stack: %s",
             grpc_error_string(error));
@@ -803,7 +803,7 @@ grpc_error* ConnectedSubchannel::CreateCall(const CallArgs& args,
   };
   grpc_error* error = grpc_call_stack_init(
       channel_stack_, 1, subchannel_call_destroy, *call, &call_args);
-  if (error != GRPC_ERROR_NONE) {
+  if (GPR_UNLIKELY(error != GRPC_ERROR_NONE)) {
     const char* error_string = grpc_error_string(error);
     gpr_log(GPR_ERROR, "error: %s", error_string);
     return error;

src/core/ext/filters/http/client/http_client_filter.cc

@@ -460,7 +460,7 @@ static size_t max_payload_size_from_args(const grpc_channel_args* args) {
   if (args != nullptr) {
     for (size_t i = 0; i < args->num_args; ++i) {
       if (0 == strcmp(args->args[i].key, GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET)) {
-        if (args->args[i].type != GRPC_ARG_INTEGER) {
+        if (GPR_UNLIKELY(args->args[i].type != GRPC_ARG_INTEGER)) {
           gpr_log(GPR_ERROR, "%s: must be an integer",
                   GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET);
         } else {
@@ -484,7 +484,7 @@ static grpc_slice user_agent_from_args(const grpc_channel_args* args,
 
   for (i = 0; args && i < args->num_args; i++) {
     if (0 == strcmp(args->args[i].key, GRPC_ARG_PRIMARY_USER_AGENT_STRING)) {
-      if (args->args[i].type != GRPC_ARG_STRING) {
+      if (GPR_UNLIKELY(args->args[i].type != GRPC_ARG_STRING)) {
         gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
                 GRPC_ARG_PRIMARY_USER_AGENT_STRING);
       } else {
@@ -503,7 +503,7 @@ static grpc_slice user_agent_from_args(const grpc_channel_args* args,
 
   for (i = 0; args && i < args->num_args; i++) {
     if (0 == strcmp(args->args[i].key, GRPC_ARG_SECONDARY_USER_AGENT_STRING)) {
-      if (args->args[i].type != GRPC_ARG_STRING) {
+      if (GPR_UNLIKELY(args->args[i].type != GRPC_ARG_STRING)) {
         gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
                 GRPC_ARG_SECONDARY_USER_AGENT_STRING);
       } else {

src/core/ext/filters/http/message_compress/message_compress_filter.cc

@@ -116,8 +116,8 @@ static grpc_error* process_send_initial_metadata(
   if (initial_metadata->idx.named.grpc_internal_encoding_request != nullptr) {
     grpc_mdelem md =
         initial_metadata->idx.named.grpc_internal_encoding_request->md;
-    if (!grpc_compression_algorithm_parse(GRPC_MDVALUE(md),
-                                          &compression_algorithm)) {
+    if (GPR_UNLIKELY(!grpc_compression_algorithm_parse(
+            GRPC_MDVALUE(md), &compression_algorithm))) {
       char* val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
       gpr_log(GPR_ERROR,
               "Invalid compression algorithm: '%s' (unknown). Ignoring.", val);
@@ -125,8 +125,8 @@ static grpc_error* process_send_initial_metadata(
       calld->message_compression_algorithm = GRPC_MESSAGE_COMPRESS_NONE;
       stream_compression_algorithm = GRPC_STREAM_COMPRESS_NONE;
     }
-    if (!GPR_BITGET(channeld->enabled_algorithms_bitset,
-                    compression_algorithm)) {
+    if (GPR_UNLIKELY(!GPR_BITGET(channeld->enabled_algorithms_bitset,
+                                 compression_algorithm))) {
       char* val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
       gpr_log(GPR_ERROR,
               "Invalid compression algorithm: '%s' (previously disabled). "

src/core/ext/transport/chttp2/client/insecure/channel_create.cc

@@ -54,7 +54,7 @@ static grpc_subchannel* client_channel_factory_create_subchannel(
 static grpc_channel* client_channel_factory_create_channel(
     grpc_client_channel_factory* cc_factory, const char* target,
     grpc_client_channel_type type, const grpc_channel_args* args) {
-  if (target == nullptr) {
+  if (GPR_UNLIKELY(target == nullptr)) {
     gpr_log(GPR_ERROR, "cannot create channel with NULL target name");
     return nullptr;
   }

src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc

@@ -50,14 +50,15 @@ static grpc_subchannel_args* get_secure_naming_subchannel_args(
     const grpc_subchannel_args* args) {
   grpc_channel_credentials* channel_credentials =
       grpc_channel_credentials_find_in_args(args->args);
-  if (channel_credentials == nullptr) {
+  if (GPR_UNLIKELY(channel_credentials == nullptr)) {
     gpr_log(GPR_ERROR,
             "Can't create subchannel: channel credentials missing for secure "
             "channel.");
     return nullptr;
   }
   // Make sure security connector does not already exist in args.
-  if (grpc_security_connector_find_in_args(args->args) != nullptr) {
+  if (GPR_UNLIKELY(grpc_security_connector_find_in_args(args->args) !=
+                   nullptr)) {
     gpr_log(GPR_ERROR,
             "Can't create subchannel: security connector already present in "
             "channel args.");
@@ -117,7 +118,7 @@ static grpc_subchannel_args* get_secure_naming_subchannel_args(
       grpc_channel_credentials_create_security_connector(
           channel_credentials, authority.get(), args_with_authority,
           &subchannel_security_connector, &new_args_from_connector);
-  if (security_status != GRPC_SECURITY_OK) {
+  if (GPR_UNLIKELY(security_status != GRPC_SECURITY_OK)) {
     gpr_log(GPR_ERROR,
             "Failed to create secure subchannel for secure name '%s'",
             authority.get());
@@ -149,7 +150,7 @@ static grpc_subchannel* client_channel_factory_create_subchannel(
     grpc_client_channel_factory* cc_factory, const grpc_subchannel_args* args) {
   grpc_subchannel_args* subchannel_args =
       get_secure_naming_subchannel_args(args);
-  if (subchannel_args == nullptr) {
+  if (GPR_UNLIKELY(subchannel_args == nullptr)) {
     gpr_log(
         GPR_ERROR,
         "Failed to create subchannel arguments during subchannel creation.");
@@ -167,7 +168,7 @@ static grpc_subchannel* client_channel_factory_create_subchannel(
 static grpc_channel* client_channel_factory_create_channel(
     grpc_client_channel_factory* cc_factory, const char* target,
     grpc_client_channel_type type, const grpc_channel_args* args) {
-  if (target == nullptr) {
+  if (GPR_UNLIKELY(target == nullptr)) {
     gpr_log(GPR_ERROR, "cannot create channel with NULL target name");
     return nullptr;
   }

src/core/ext/transport/chttp2/server/insecure/server_chttp2.cc

@@ -35,7 +35,7 @@ int grpc_server_add_insecure_http2_port(grpc_server* server, const char* addr) {
   grpc_error* err = grpc_chttp2_server_add_port(
       server, addr,
       grpc_channel_args_copy(grpc_server_get_channel_args(server)), &port_num);
-  if (err != GRPC_ERROR_NONE) {
+  if (GPR_UNLIKELY(err != GRPC_ERROR_NONE)) {
     const char* msg = grpc_error_string(err);
     gpr_log(GPR_ERROR, "%s", msg);
 

src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.cc

@@ -79,7 +79,7 @@ done:
     GRPC_SECURITY_CONNECTOR_UNREF(&sc->base, "server");
   }
 
-  if (err != GRPC_ERROR_NONE) {
+  if (GPR_UNLIKELY(err != GRPC_ERROR_NONE)) {
     const char* msg = grpc_error_string(err);
     gpr_log(GPR_ERROR, "%s", msg);
 

src/core/ext/transport/chttp2/transport/bin_decoder.cc

@@ -55,7 +55,7 @@ static bool input_is_valid(uint8_t* input_ptr, size_t length) {
   size_t i;
 
   for (i = 0; i < length; ++i) {
-    if ((decode_table[input_ptr[i]] & 0xC0) != 0) {
+    if (GPR_UNLIKELY((decode_table[input_ptr[i]] & 0xC0) != 0)) {
       gpr_log(GPR_ERROR,
               "Base64 decoding failed, invalid character '%c' in base64 "
               "input.\n",
@@ -86,14 +86,14 @@ size_t grpc_chttp2_base64_infer_length_after_decode(const grpc_slice& slice) {
   while (len > 0 && bytes[len - 1] == '=') {
     len--;
   }
-  if (GRPC_SLICE_LENGTH(slice) - len > 2) {
+  if (GPR_UNLIKELY(GRPC_SLICE_LENGTH(slice) - len > 2)) {
     gpr_log(GPR_ERROR,
             "Base64 decoding failed. Input has more than 2 paddings.");
     return 0;
   }
   size_t tuples = len / 4;
   size_t tail_case = len % 4;
-  if (tail_case == 1) {
+  if (GPR_UNLIKELY(tail_case == 1)) {
     gpr_log(GPR_ERROR,
             "Base64 decoding failed. Input has a length of %zu (without"
             " padding), which is invalid.\n",
@@ -164,7 +164,7 @@ grpc_slice grpc_chttp2_base64_decode(grpc_slice input) {
   struct grpc_base64_decode_context ctx;
   grpc_slice output;
 
-  if (input_length % 4 != 0) {
+  if (GPR_UNLIKELY(input_length % 4 != 0)) {
     gpr_log(GPR_ERROR,
             "Base64 decoding failed, input of "
             "grpc_chttp2_base64_decode has a length of %d, which is not a "
@@ -190,7 +190,7 @@ grpc_slice grpc_chttp2_base64_decode(grpc_slice input) {
   ctx.output_end = GRPC_SLICE_END_PTR(output);
   ctx.contains_tail = false;
 
-  if (!grpc_base64_decode_partial(&ctx)) {
+  if (GPR_UNLIKELY(!grpc_base64_decode_partial(&ctx))) {
     char* s = grpc_slice_to_c_string(input);
     gpr_log(GPR_ERROR, "Base64 decoding failed, input string:\n%s\n", s);
     gpr_free(s);
@@ -209,7 +209,7 @@ grpc_slice grpc_chttp2_base64_decode_with_length(grpc_slice input,
   struct grpc_base64_decode_context ctx;
 
   // The length of a base64 string cannot be 4 * n + 1
-  if (input_length % 4 == 1) {
+  if (GPR_UNLIKELY(input_length % 4 == 1)) {
     gpr_log(GPR_ERROR,
             "Base64 decoding failed, input of "
             "grpc_chttp2_base64_decode_with_length has a length of %d, which "
@@ -219,7 +219,8 @@ grpc_slice grpc_chttp2_base64_decode_with_length(grpc_slice input,
     return grpc_empty_slice();
   }
 
-  if (output_length > input_length / 4 * 3 + tail_xtra[input_length % 4]) {
+  if (GPR_UNLIKELY(output_length >
+                   input_length / 4 * 3 + tail_xtra[input_length % 4])) {
     gpr_log(
         GPR_ERROR,
         "Base64 decoding failed, output_length %d is longer "
@@ -236,7 +237,7 @@ grpc_slice grpc_chttp2_base64_decode_with_length(grpc_slice input,
   ctx.output_end = GRPC_SLICE_END_PTR(output);
   ctx.contains_tail = true;
 
-  if (!grpc_base64_decode_partial(&ctx)) {
+  if (GPR_UNLIKELY(!grpc_base64_decode_partial(&ctx))) {
     char* s = grpc_slice_to_c_string(input);
     gpr_log(GPR_ERROR, "Base64 decoding failed, input string:\n%s\n", s);
     gpr_free(s);

src/core/ext/transport/chttp2/transport/chttp2_transport.cc

@@ -368,7 +368,7 @@ static void init_transport(grpc_chttp2_transport* t,
         const int value =
             grpc_channel_arg_get_integer(&channel_args->args[i], options);
         if (value >= 0) {
-          if ((t->next_stream_id & 1) != (value & 1)) {
+          if (GPR_UNLIKELY((t->next_stream_id & 1) != (value & 1))) {
             gpr_log(GPR_ERROR, "%s: low bit must be %d on %s",
                     GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER,
                     t->next_stream_id & 1, is_client ? "client" : "server");
@@ -447,7 +447,7 @@ static void init_transport(grpc_chttp2_transport* t,
             grpc_channel_arg_get_integer(&channel_args->args[i], {0, 0, 1}));
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_OPTIMIZATION_TARGET)) {
-        if (channel_args->args[i].type != GRPC_ARG_STRING) {
+        if (GPR_UNLIKELY(channel_args->args[i].type != GRPC_ARG_STRING)) {
           gpr_log(GPR_ERROR, "%s should be a string",
                   GRPC_ARG_OPTIMIZATION_TARGET);
         } else if (0 == strcmp(channel_args->args[i].value.string, "blend")) {
@@ -718,7 +718,7 @@ static void destroy_stream_locked(void* sp, grpc_error* error) {
   grpc_chttp2_list_remove_stalled_by_stream(t, s);
 
   for (int i = 0; i < STREAM_LIST_COUNT; i++) {
-    if (s->included[i]) {
+    if (GPR_UNLIKELY(s->included[i])) {
       gpr_log(GPR_ERROR, "%s stream %d still included in list %d",
               t->is_client ? "client" : "server", s->id, i);
       abort();
@@ -1088,8 +1088,9 @@ void grpc_chttp2_add_incoming_goaway(grpc_chttp2_transport* t,
    * data equal to "too_many_pings", it should log the occurrence at a log level
    * that is enabled by default and double the configured KEEPALIVE_TIME used
    * for new connections on that channel. */
-  if (t->is_client && goaway_error == GRPC_HTTP2_ENHANCE_YOUR_CALM &&
-      grpc_slice_str_cmp(goaway_text, "too_many_pings") == 0) {
+  if (GPR_UNLIKELY(t->is_client &&
+                   goaway_error == GRPC_HTTP2_ENHANCE_YOUR_CALM &&
+                   grpc_slice_str_cmp(goaway_text, "too_many_pings") == 0)) {
     gpr_log(GPR_ERROR,
             "Received a GOAWAY with error code ENHANCE_YOUR_CALM and debug "
             "data equal to \"too_many_pings\"");
@@ -2701,7 +2702,7 @@ static void keepalive_watchdog_fired_locked(void* arg, grpc_error* error) {
   } else {
     /* The watchdog timer should have been cancelled by
      * finish_keepalive_ping_locked. */
-    if (error != GRPC_ERROR_CANCELLED) {
+    if (GPR_UNLIKELY(error != GRPC_ERROR_CANCELLED)) {
       gpr_log(GPR_ERROR, "keepalive_ping_end state error: %d (expect: %d)",
               t->keepalive_state, GRPC_CHTTP2_KEEPALIVE_STATE_PINGING);
     }

src/core/ext/transport/chttp2/transport/parsing.cc

@@ -422,7 +422,8 @@ static void on_initial_header(void* tp, grpc_mdelem md) {
     if (cached_timeout != nullptr) {
       timeout = *cached_timeout;
     } else {
-      if (!grpc_http2_decode_timeout(GRPC_MDVALUE(md), &timeout)) {
+      if (GPR_UNLIKELY(
+              !grpc_http2_decode_timeout(GRPC_MDVALUE(md), &timeout))) {
         char* val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
         gpr_log(GPR_ERROR, "Ignoring bad timeout value '%s'", val);
         gpr_free(val);
@@ -550,15 +551,15 @@ static grpc_error* init_header_frame_parser(grpc_chttp2_transport* t,
   /* could be a new grpc_chttp2_stream or an existing grpc_chttp2_stream */
   s = grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
   if (s == nullptr) {
-    if (is_continuation) {
+    if (GPR_UNLIKELY(is_continuation)) {
       GRPC_CHTTP2_IF_TRACING(
           gpr_log(GPR_ERROR,
                   "grpc_chttp2_stream disbanded before CONTINUATION received"));
       return init_skip_frame_parser(t, 1);
     }
     if (t->is_client) {
-      if ((t->incoming_stream_id & 1) &&
-          t->incoming_stream_id < t->next_stream_id) {
+      if (GPR_LIKELY((t->incoming_stream_id & 1) &&
+                     t->incoming_stream_id < t->next_stream_id)) {
         /* this is an old (probably cancelled) grpc_chttp2_stream */
       } else {
         GRPC_CHTTP2_IF_TRACING(gpr_log(
@@ -569,7 +570,7 @@ static grpc_error* init_header_frame_parser(grpc_chttp2_transport* t,
         grpc_chttp2_hpack_parser_set_has_priority(&t->hpack_parser);
       }
       return err;
-    } else if (t->last_new_stream_id >= t->incoming_stream_id) {
+    } else if (GPR_UNLIKELY(t->last_new_stream_id >= t->incoming_stream_id)) {
       GRPC_CHTTP2_IF_TRACING(gpr_log(
           GPR_ERROR,
           "ignoring out of order new grpc_chttp2_stream request on server; "
@@ -577,21 +578,22 @@ static grpc_error* init_header_frame_parser(grpc_chttp2_transport* t,
           "id=%d, new grpc_chttp2_stream id=%d",
           t->last_new_stream_id, t->incoming_stream_id));
       return init_skip_frame_parser(t, 1);
-    } else if ((t->incoming_stream_id & 1) == 0) {
+    } else if (GPR_UNLIKELY((t->incoming_stream_id & 1) == 0)) {
       GRPC_CHTTP2_IF_TRACING(gpr_log(
           GPR_ERROR,
           "ignoring grpc_chttp2_stream with non-client generated index %d",
           t->incoming_stream_id));
       return init_skip_frame_parser(t, 1);
-    } else if (grpc_chttp2_stream_map_size(&t->stream_map) >=
+    } else if (GPR_UNLIKELY(
+                   grpc_chttp2_stream_map_size(&t->stream_map) >=
                    t->settings[GRPC_ACKED_SETTINGS]
-                          [GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS]) {
+                              [GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS])) {
       return GRPC_ERROR_CREATE_FROM_STATIC_STRING("Max stream count exceeded");
     }
     t->last_new_stream_id = t->incoming_stream_id;
     s = t->incoming_stream =
         grpc_chttp2_parsing_accept_stream(t, t->incoming_stream_id);
-    if (s == nullptr) {
+    if (GPR_UNLIKELY(s == nullptr)) {
       GRPC_CHTTP2_IF_TRACING(
           gpr_log(GPR_ERROR, "grpc_chttp2_stream not accepted"));
       return init_skip_frame_parser(t, 1);
@@ -601,7 +603,7 @@ static grpc_error* init_header_frame_parser(grpc_chttp2_transport* t,
   }
   GPR_ASSERT(s != nullptr);
   s->stats.incoming.framing_bytes += 9;
-  if (s->read_closed) {
+  if (GPR_UNLIKELY(s->read_closed)) {
     GRPC_CHTTP2_IF_TRACING(gpr_log(
         GPR_ERROR, "skipping already closed grpc_chttp2_stream header"));
     t->incoming_stream = nullptr;
@@ -723,7 +725,7 @@ static grpc_error* parse_frame_slice(grpc_chttp2_transport* t, grpc_slice slice,
                                      int is_last) {
   grpc_chttp2_stream* s = t->incoming_stream;
   grpc_error* err = t->parser(t->parser_data, t, s, slice, is_last);
-  if (err == GRPC_ERROR_NONE) {
+  if (GPR_LIKELY(err == GRPC_ERROR_NONE)) {
     return err;
   } else if (grpc_error_get_int(err, GRPC_ERROR_INT_STREAM_ID, nullptr)) {
     if (grpc_http_trace.enabled()) {

src/core/ext/transport/chttp2/transport/writing.cc

@@ -337,10 +337,10 @@ class DataSendContext {
          s_->fetching_send_message == nullptr);
     if (is_last_data_frame && s_->send_trailing_metadata != nullptr &&
         s_->stream_compression_ctx != nullptr) {
-      if (!grpc_stream_compress(
+      if (GPR_UNLIKELY(!grpc_stream_compress(
               s_->stream_compression_ctx, &s_->flow_controlled_buffer,
               &s_->compressed_data_buffer, nullptr, MAX_SIZE_T,
-              GRPC_STREAM_COMPRESSION_FLUSH_FINISH)) {
+              GRPC_STREAM_COMPRESSION_FLUSH_FINISH))) {
         gpr_log(GPR_ERROR, "Stream compression failed.");
       }
       grpc_stream_compression_context_destroy(s_->stream_compression_ctx);
@@ -368,10 +368,10 @@ class DataSendContext {
           grpc_stream_compression_context_create(s_->stream_compression_method);
     }
     s_->uncompressed_data_size = s_->flow_controlled_buffer.length;
-    if (!grpc_stream_compress(s_->stream_compression_ctx,
-                              &s_->flow_controlled_buffer,
+    if (GPR_UNLIKELY(!grpc_stream_compress(
+            s_->stream_compression_ctx, &s_->flow_controlled_buffer,
             &s_->compressed_data_buffer, nullptr, MAX_SIZE_T,
-                              GRPC_STREAM_COMPRESSION_FLUSH_SYNC)) {
+            GRPC_STREAM_COMPRESSION_FLUSH_SYNC))) {
       gpr_log(GPR_ERROR, "Stream compression failed.");
     }
   }

src/core/ext/transport/cronet/transport/cronet_transport.cc

@@ -360,7 +360,7 @@ static void remove_from_storage(struct stream_obj* s,
                    s->storage.num_pending_ops);
         gpr_free(oas);
         break;
-      } else if (curr->next == nullptr) {
+      } else if (GPR_UNLIKELY(curr->next == nullptr)) {
         CRONET_LOG(GPR_ERROR, "Reached end of LL and did not find op to free");
       }
     }
@@ -1054,7 +1054,7 @@ static enum e_op_result execute_stream_op(struct op_and_state* oas) {
         GPR_ASSERT(false);
       }
       grpc_slice_buffer_add(&write_slice_buffer, slice);
-      if (write_slice_buffer.count != 1) {
+      if (GPR_UNLIKELY(write_slice_buffer.count != 1)) {
         /* Empty request not handled yet */
         gpr_log(GPR_ERROR, "Empty request is not supported");
         GPR_ASSERT(write_slice_buffer.count == 1);
@@ -1455,7 +1455,7 @@ grpc_transport* grpc_create_cronet_transport(void* engine, const char* target,
     for (size_t i = 0; i < args->num_args; i++) {
       if (0 ==
           strcmp(args->args[i].key, GRPC_ARG_USE_CRONET_PACKET_COALESCING)) {
-        if (args->args[i].type != GRPC_ARG_INTEGER) {
+        if (GPR_UNLIKELY(args->args[i].type != GRPC_ARG_INTEGER)) {
           gpr_log(GPR_ERROR, "%s ignored: it must be an integer",
                   GRPC_ARG_USE_CRONET_PACKET_COALESCING);
         } else {