| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include "src/core/ext/filters/client_channel/client_channel.h" |
| |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/string_util.h> |
| #include <grpc/support/sync.h> |
| #include <grpc/support/useful.h> |
| |
| #include "src/core/ext/filters/client_channel/http_connect_handshaker.h" |
| #include "src/core/ext/filters/client_channel/lb_policy_registry.h" |
| #include "src/core/ext/filters/client_channel/proxy_mapper_registry.h" |
| #include "src/core/ext/filters/client_channel/resolver_registry.h" |
| #include "src/core/ext/filters/client_channel/retry_throttle.h" |
| #include "src/core/ext/filters/client_channel/subchannel.h" |
| #include "src/core/ext/filters/deadline/deadline_filter.h" |
| #include "src/core/lib/channel/channel_args.h" |
| #include "src/core/lib/channel/connected_channel.h" |
| #include "src/core/lib/iomgr/combiner.h" |
| #include "src/core/lib/iomgr/iomgr.h" |
| #include "src/core/lib/iomgr/polling_entity.h" |
| #include "src/core/lib/profiling/timers.h" |
| #include "src/core/lib/slice/slice_internal.h" |
| #include "src/core/lib/support/string.h" |
| #include "src/core/lib/surface/channel.h" |
| #include "src/core/lib/transport/connectivity_state.h" |
| #include "src/core/lib/transport/metadata.h" |
| #include "src/core/lib/transport/metadata_batch.h" |
| #include "src/core/lib/transport/service_config.h" |
| #include "src/core/lib/transport/static_metadata.h" |
| |
| /* Client channel implementation */ |
| |
| /************************************************************************* |
| * METHOD-CONFIG TABLE |
| */ |
| |
| typedef enum { |
| /* zero so it can be default initialized */ |
| WAIT_FOR_READY_UNSET = 0, |
| WAIT_FOR_READY_FALSE, |
| WAIT_FOR_READY_TRUE |
| } wait_for_ready_value; |
| |
| typedef struct { |
| gpr_refcount refs; |
| gpr_timespec timeout; |
| wait_for_ready_value wait_for_ready; |
| } method_parameters; |
| |
| static method_parameters *method_parameters_ref( |
| method_parameters *method_params) { |
| gpr_ref(&method_params->refs); |
| return method_params; |
| } |
| |
| static void method_parameters_unref(method_parameters *method_params) { |
| if (gpr_unref(&method_params->refs)) { |
| gpr_free(method_params); |
| } |
| } |
| |
| static void method_parameters_free(grpc_exec_ctx *exec_ctx, void *value) { |
| method_parameters_unref(value); |
| } |
| |
| static bool parse_wait_for_ready(grpc_json *field, |
| wait_for_ready_value *wait_for_ready) { |
| if (field->type != GRPC_JSON_TRUE && field->type != GRPC_JSON_FALSE) { |
| return false; |
| } |
| *wait_for_ready = field->type == GRPC_JSON_TRUE ? WAIT_FOR_READY_TRUE |
| : WAIT_FOR_READY_FALSE; |
| return true; |
| } |
| |
| static bool parse_timeout(grpc_json *field, gpr_timespec *timeout) { |
| if (field->type != GRPC_JSON_STRING) return false; |
| size_t len = strlen(field->value); |
| if (field->value[len - 1] != 's') return false; |
| char *buf = gpr_strdup(field->value); |
| buf[len - 1] = '\0'; // Remove trailing 's'. |
| char *decimal_point = strchr(buf, '.'); |
| if (decimal_point != NULL) { |
| *decimal_point = '\0'; |
| timeout->tv_nsec = gpr_parse_nonnegative_int(decimal_point + 1); |
| if (timeout->tv_nsec == -1) { |
| gpr_free(buf); |
| return false; |
| } |
| // There should always be exactly 3, 6, or 9 fractional digits. |
| int multiplier = 1; |
| switch (strlen(decimal_point + 1)) { |
| case 9: |
| break; |
| case 6: |
| multiplier *= 1000; |
| break; |
| case 3: |
| multiplier *= 1000000; |
| break; |
| default: // Unsupported number of digits. |
| gpr_free(buf); |
| return false; |
| } |
| timeout->tv_nsec *= multiplier; |
| } |
| timeout->tv_sec = gpr_parse_nonnegative_int(buf); |
| gpr_free(buf); |
| if (timeout->tv_sec == -1) return false; |
| return true; |
| } |
| |
| static void *method_parameters_create_from_json(const grpc_json *json) { |
| wait_for_ready_value wait_for_ready = WAIT_FOR_READY_UNSET; |
| gpr_timespec timeout = {0, 0, GPR_TIMESPAN}; |
| for (grpc_json *field = json->child; field != NULL; field = field->next) { |
| if (field->key == NULL) continue; |
| if (strcmp(field->key, "waitForReady") == 0) { |
| if (wait_for_ready != WAIT_FOR_READY_UNSET) return NULL; // Duplicate. |
| if (!parse_wait_for_ready(field, &wait_for_ready)) return NULL; |
| } else if (strcmp(field->key, "timeout") == 0) { |
| if (timeout.tv_sec > 0 || timeout.tv_nsec > 0) return NULL; // Duplicate. |
| if (!parse_timeout(field, &timeout)) return NULL; |
| } |
| } |
| method_parameters *value = gpr_malloc(sizeof(method_parameters)); |
| gpr_ref_init(&value->refs, 1); |
| value->timeout = timeout; |
| value->wait_for_ready = wait_for_ready; |
| return value; |
| } |
| |
| /************************************************************************* |
| * CHANNEL-WIDE FUNCTIONS |
| */ |
| |
| typedef struct client_channel_channel_data { |
| /** resolver for this channel */ |
| grpc_resolver *resolver; |
| /** have we started resolving this channel */ |
| bool started_resolving; |
| /** is deadline checking enabled? */ |
| bool deadline_checking_enabled; |
| /** client channel factory */ |
| grpc_client_channel_factory *client_channel_factory; |
| |
| /** combiner protecting all variables below in this data structure */ |
| grpc_combiner *combiner; |
| /** currently active load balancer */ |
| grpc_lb_policy *lb_policy; |
| /** retry throttle data */ |
| grpc_server_retry_throttle_data *retry_throttle_data; |
| /** maps method names to method_parameters structs */ |
| grpc_slice_hash_table *method_params_table; |
| /** incoming resolver result - set by resolver.next() */ |
| grpc_channel_args *resolver_result; |
| /** a list of closures that are all waiting for config to come in */ |
| grpc_closure_list waiting_for_config_closures; |
| /** resolver callback */ |
| grpc_closure on_resolver_result_changed; |
| /** connectivity state being tracked */ |
| grpc_connectivity_state_tracker state_tracker; |
| /** when an lb_policy arrives, should we try to exit idle */ |
| bool exit_idle_when_lb_policy_arrives; |
| /** owning stack */ |
| grpc_channel_stack *owning_stack; |
| /** interested parties (owned) */ |
| grpc_pollset_set *interested_parties; |
| |
| /* the following properties are guarded by a mutex since API's require them |
| to be instantaneously available */ |
| gpr_mu info_mu; |
| char *info_lb_policy_name; |
| /** service config in JSON form */ |
| char *info_service_config_json; |
| } channel_data; |
| |
| /** We create one watcher for each new lb_policy that is returned from a |
| resolver, to watch for state changes from the lb_policy. When a state |
| change is seen, we update the channel, and create a new watcher. */ |
| typedef struct { |
| channel_data *chand; |
| grpc_closure on_changed; |
| grpc_connectivity_state state; |
| grpc_lb_policy *lb_policy; |
| } lb_policy_connectivity_watcher; |
| |
| static void watch_lb_policy_locked(grpc_exec_ctx *exec_ctx, channel_data *chand, |
| grpc_lb_policy *lb_policy, |
| grpc_connectivity_state current_state); |
| |
| static void set_channel_connectivity_state_locked(grpc_exec_ctx *exec_ctx, |
| channel_data *chand, |
| grpc_connectivity_state state, |
| grpc_error *error, |
| const char *reason) { |
| /* TODO: Improve failure handling: |
| * - Make it possible for policies to return GRPC_CHANNEL_TRANSIENT_FAILURE. |
| * - Hand over pending picks from old policies during the switch that happens |
| * when resolver provides an update. */ |
| if (chand->lb_policy != NULL) { |
| if (state == GRPC_CHANNEL_TRANSIENT_FAILURE) { |
| /* cancel picks with wait_for_ready=false */ |
| grpc_lb_policy_cancel_picks_locked( |
| exec_ctx, chand->lb_policy, |
| /* mask= */ GRPC_INITIAL_METADATA_WAIT_FOR_READY, |
| /* check= */ 0, GRPC_ERROR_REF(error)); |
| } else if (state == GRPC_CHANNEL_SHUTDOWN) { |
| /* cancel all picks */ |
| grpc_lb_policy_cancel_picks_locked(exec_ctx, chand->lb_policy, |
| /* mask= */ 0, /* check= */ 0, |
| GRPC_ERROR_REF(error)); |
| } |
| } |
| grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, state, error, |
| reason); |
| } |
| |
| static void on_lb_policy_state_changed_locked(grpc_exec_ctx *exec_ctx, |
| void *arg, grpc_error *error) { |
| lb_policy_connectivity_watcher *w = arg; |
| grpc_connectivity_state publish_state = w->state; |
| /* check if the notification is for the latest policy */ |
| if (w->lb_policy == w->chand->lb_policy) { |
| if (publish_state == GRPC_CHANNEL_SHUTDOWN && w->chand->resolver != NULL) { |
| publish_state = GRPC_CHANNEL_TRANSIENT_FAILURE; |
| grpc_resolver_channel_saw_error_locked(exec_ctx, w->chand->resolver); |
| GRPC_LB_POLICY_UNREF(exec_ctx, w->chand->lb_policy, "channel"); |
| w->chand->lb_policy = NULL; |
| } |
| set_channel_connectivity_state_locked(exec_ctx, w->chand, publish_state, |
| GRPC_ERROR_REF(error), "lb_changed"); |
| if (w->state != GRPC_CHANNEL_SHUTDOWN) { |
| watch_lb_policy_locked(exec_ctx, w->chand, w->lb_policy, w->state); |
| } |
| } |
| |
| GRPC_CHANNEL_STACK_UNREF(exec_ctx, w->chand->owning_stack, "watch_lb_policy"); |
| gpr_free(w); |
| } |
| |
| static void watch_lb_policy_locked(grpc_exec_ctx *exec_ctx, channel_data *chand, |
| grpc_lb_policy *lb_policy, |
| grpc_connectivity_state current_state) { |
| lb_policy_connectivity_watcher *w = gpr_malloc(sizeof(*w)); |
| GRPC_CHANNEL_STACK_REF(chand->owning_stack, "watch_lb_policy"); |
| |
| w->chand = chand; |
| grpc_closure_init(&w->on_changed, on_lb_policy_state_changed_locked, w, |
| grpc_combiner_scheduler(chand->combiner, false)); |
| w->state = current_state; |
| w->lb_policy = lb_policy; |
| grpc_lb_policy_notify_on_state_change_locked(exec_ctx, lb_policy, &w->state, |
| &w->on_changed); |
| } |
| |
| typedef struct { |
| char *server_name; |
| grpc_server_retry_throttle_data *retry_throttle_data; |
| } service_config_parsing_state; |
| |
| static void parse_retry_throttle_params(const grpc_json *field, void *arg) { |
| service_config_parsing_state *parsing_state = arg; |
| if (strcmp(field->key, "retryThrottling") == 0) { |
| if (parsing_state->retry_throttle_data != NULL) return; // Duplicate. |
| if (field->type != GRPC_JSON_OBJECT) return; |
| int max_milli_tokens = 0; |
| int milli_token_ratio = 0; |
| for (grpc_json *sub_field = field->child; sub_field != NULL; |
| sub_field = sub_field->next) { |
| if (sub_field->key == NULL) return; |
| if (strcmp(sub_field->key, "maxTokens") == 0) { |
| if (max_milli_tokens != 0) return; // Duplicate. |
| if (sub_field->type != GRPC_JSON_NUMBER) return; |
| max_milli_tokens = gpr_parse_nonnegative_int(sub_field->value); |
| if (max_milli_tokens == -1) return; |
| max_milli_tokens *= 1000; |
| } else if (strcmp(sub_field->key, "tokenRatio") == 0) { |
| if (milli_token_ratio != 0) return; // Duplicate. |
| if (sub_field->type != GRPC_JSON_NUMBER) return; |
| // We support up to 3 decimal digits. |
| size_t whole_len = strlen(sub_field->value); |
| uint32_t multiplier = 1; |
| uint32_t decimal_value = 0; |
| const char *decimal_point = strchr(sub_field->value, '.'); |
| if (decimal_point != NULL) { |
| whole_len = (size_t)(decimal_point - sub_field->value); |
| multiplier = 1000; |
| size_t decimal_len = strlen(decimal_point + 1); |
| if (decimal_len > 3) decimal_len = 3; |
| if (!gpr_parse_bytes_to_uint32(decimal_point + 1, decimal_len, |
| &decimal_value)) { |
| return; |
| } |
| uint32_t decimal_multiplier = 1; |
| for (size_t i = 0; i < (3 - decimal_len); ++i) { |
| decimal_multiplier *= 10; |
| } |
| decimal_value *= decimal_multiplier; |
| } |
| uint32_t whole_value; |
| if (!gpr_parse_bytes_to_uint32(sub_field->value, whole_len, |
| &whole_value)) { |
| return; |
| } |
| milli_token_ratio = (int)((whole_value * multiplier) + decimal_value); |
| if (milli_token_ratio <= 0) return; |
| } |
| } |
| parsing_state->retry_throttle_data = |
| grpc_retry_throttle_map_get_data_for_server( |
| parsing_state->server_name, max_milli_tokens, milli_token_ratio); |
| } |
| } |
| |
| // Wrap a closure associated with \a lb_policy. The associated callback (\a |
| // wrapped_on_pick_closure_cb) is responsible for unref'ing \a lb_policy after |
| // scheduling \a wrapped_closure. |
| typedef struct wrapped_on_pick_closure_arg { |
| /* the closure instance using this struct as argument */ |
| grpc_closure wrapper_closure; |
| |
| /* the original closure. Usually a on_complete/notify cb for pick() and ping() |
| * calls against the internal RR instance, respectively. */ |
| grpc_closure *wrapped_closure; |
| |
| /* The policy instance related to the closure */ |
| grpc_lb_policy *lb_policy; |
| } wrapped_on_pick_closure_arg; |
| |
| // Invoke \a arg->wrapped_closure, unref \a arg->lb_policy and free \a arg. |
| static void wrapped_on_pick_closure_cb(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| wrapped_on_pick_closure_arg *wc_arg = arg; |
| GPR_ASSERT(wc_arg != NULL); |
| GPR_ASSERT(wc_arg->wrapped_closure != NULL); |
| GPR_ASSERT(wc_arg->lb_policy != NULL); |
| grpc_closure_run(exec_ctx, wc_arg->wrapped_closure, GRPC_ERROR_REF(error)); |
| GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->lb_policy, "pick_subchannel_wrapping"); |
| gpr_free(wc_arg); |
| } |
| |
| static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx, |
| void *arg, grpc_error *error) { |
| channel_data *chand = arg; |
| char *lb_policy_name = NULL; |
| grpc_lb_policy *lb_policy = NULL; |
| grpc_lb_policy *old_lb_policy; |
| grpc_slice_hash_table *method_params_table = NULL; |
| grpc_connectivity_state state = GRPC_CHANNEL_TRANSIENT_FAILURE; |
| bool exit_idle = false; |
| grpc_error *state_error = |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("No load balancing policy"); |
| char *service_config_json = NULL; |
| service_config_parsing_state parsing_state; |
| memset(&parsing_state, 0, sizeof(parsing_state)); |
| |
| if (chand->resolver_result != NULL) { |
| // Find LB policy name. |
| const grpc_arg *channel_arg = |
| grpc_channel_args_find(chand->resolver_result, GRPC_ARG_LB_POLICY_NAME); |
| if (channel_arg != NULL) { |
| GPR_ASSERT(channel_arg->type == GRPC_ARG_STRING); |
| lb_policy_name = channel_arg->value.string; |
| } |
| // Special case: If all of the addresses are balancer addresses, |
| // assume that we should use the grpclb policy, regardless of what the |
| // resolver actually specified. |
| channel_arg = |
| grpc_channel_args_find(chand->resolver_result, GRPC_ARG_LB_ADDRESSES); |
| if (channel_arg != NULL && channel_arg->type == GRPC_ARG_POINTER) { |
| grpc_lb_addresses *addresses = channel_arg->value.pointer.p; |
| bool found_backend_address = false; |
| for (size_t i = 0; i < addresses->num_addresses; ++i) { |
| if (!addresses->addresses[i].is_balancer) { |
| found_backend_address = true; |
| break; |
| } |
| } |
| if (!found_backend_address) { |
| if (lb_policy_name != NULL && strcmp(lb_policy_name, "grpclb") != 0) { |
| gpr_log(GPR_INFO, |
| "resolver requested LB policy %s but provided only balancer " |
| "addresses, no backend addresses -- forcing use of grpclb LB " |
| "policy", |
| lb_policy_name); |
| } |
| lb_policy_name = "grpclb"; |
| } |
| } |
| // Use pick_first if nothing was specified and we didn't select grpclb |
| // above. |
| if (lb_policy_name == NULL) lb_policy_name = "pick_first"; |
| // Instantiate LB policy. |
| grpc_lb_policy_args lb_policy_args; |
| lb_policy_args.args = chand->resolver_result; |
| lb_policy_args.client_channel_factory = chand->client_channel_factory; |
| lb_policy_args.combiner = chand->combiner; |
| lb_policy = |
| grpc_lb_policy_create(exec_ctx, lb_policy_name, &lb_policy_args); |
| if (lb_policy != NULL) { |
| GRPC_LB_POLICY_REF(lb_policy, "config_change"); |
| GRPC_ERROR_UNREF(state_error); |
| state = grpc_lb_policy_check_connectivity_locked(exec_ctx, lb_policy, |
| &state_error); |
| } |
| // Find service config. |
| channel_arg = |
| grpc_channel_args_find(chand->resolver_result, GRPC_ARG_SERVICE_CONFIG); |
| if (channel_arg != NULL) { |
| GPR_ASSERT(channel_arg->type == GRPC_ARG_STRING); |
| service_config_json = gpr_strdup(channel_arg->value.string); |
| grpc_service_config *service_config = |
| grpc_service_config_create(service_config_json); |
| if (service_config != NULL) { |
| channel_arg = |
| grpc_channel_args_find(chand->resolver_result, GRPC_ARG_SERVER_URI); |
| GPR_ASSERT(channel_arg != NULL); |
| GPR_ASSERT(channel_arg->type == GRPC_ARG_STRING); |
| grpc_uri *uri = |
| grpc_uri_parse(exec_ctx, channel_arg->value.string, true); |
| GPR_ASSERT(uri->path[0] != '\0'); |
| parsing_state.server_name = |
| uri->path[0] == '/' ? uri->path + 1 : uri->path; |
| grpc_service_config_parse_global_params( |
| service_config, parse_retry_throttle_params, &parsing_state); |
| parsing_state.server_name = NULL; |
| grpc_uri_destroy(uri); |
| method_params_table = grpc_service_config_create_method_config_table( |
| exec_ctx, service_config, method_parameters_create_from_json, |
| method_parameters_free); |
| grpc_service_config_destroy(service_config); |
| } |
| } |
| // Before we clean up, save a copy of lb_policy_name, since it might |
| // be pointing to data inside chand->resolver_result. |
| // The copy will be saved in chand->lb_policy_name below. |
| lb_policy_name = gpr_strdup(lb_policy_name); |
| grpc_channel_args_destroy(exec_ctx, chand->resolver_result); |
| chand->resolver_result = NULL; |
| } |
| |
| if (lb_policy != NULL) { |
| grpc_pollset_set_add_pollset_set(exec_ctx, lb_policy->interested_parties, |
| chand->interested_parties); |
| } |
| |
| gpr_mu_lock(&chand->info_mu); |
| if (lb_policy_name != NULL) { |
| gpr_free(chand->info_lb_policy_name); |
| chand->info_lb_policy_name = lb_policy_name; |
| } |
| old_lb_policy = chand->lb_policy; |
| chand->lb_policy = lb_policy; |
| if (service_config_json != NULL) { |
| gpr_free(chand->info_service_config_json); |
| chand->info_service_config_json = service_config_json; |
| } |
| gpr_mu_unlock(&chand->info_mu); |
| |
| if (chand->retry_throttle_data != NULL) { |
| grpc_server_retry_throttle_data_unref(chand->retry_throttle_data); |
| } |
| chand->retry_throttle_data = parsing_state.retry_throttle_data; |
| if (chand->method_params_table != NULL) { |
| grpc_slice_hash_table_unref(exec_ctx, chand->method_params_table); |
| } |
| chand->method_params_table = method_params_table; |
| if (lb_policy != NULL) { |
| grpc_closure_list_sched(exec_ctx, &chand->waiting_for_config_closures); |
| } else if (chand->resolver == NULL /* disconnected */) { |
| grpc_closure_list_fail_all(&chand->waiting_for_config_closures, |
| GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( |
| "Channel disconnected", &error, 1)); |
| grpc_closure_list_sched(exec_ctx, &chand->waiting_for_config_closures); |
| } |
| if (lb_policy != NULL && chand->exit_idle_when_lb_policy_arrives) { |
| GRPC_LB_POLICY_REF(lb_policy, "exit_idle"); |
| exit_idle = true; |
| chand->exit_idle_when_lb_policy_arrives = false; |
| } |
| |
| if (error == GRPC_ERROR_NONE && chand->resolver) { |
| set_channel_connectivity_state_locked( |
| exec_ctx, chand, state, GRPC_ERROR_REF(state_error), "new_lb+resolver"); |
| if (lb_policy != NULL) { |
| watch_lb_policy_locked(exec_ctx, chand, lb_policy, state); |
| } |
| GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver"); |
| grpc_resolver_next_locked(exec_ctx, chand->resolver, |
| &chand->resolver_result, |
| &chand->on_resolver_result_changed); |
| } else { |
| if (chand->resolver != NULL) { |
| grpc_resolver_shutdown_locked(exec_ctx, chand->resolver); |
| GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel"); |
| chand->resolver = NULL; |
| } |
| grpc_error *refs[] = {error, state_error}; |
| set_channel_connectivity_state_locked( |
| exec_ctx, chand, GRPC_CHANNEL_SHUTDOWN, |
| GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( |
| "Got config after disconnection", refs, GPR_ARRAY_SIZE(refs)), |
| "resolver_gone"); |
| } |
| |
| if (exit_idle) { |
| grpc_lb_policy_exit_idle_locked(exec_ctx, lb_policy); |
| GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "exit_idle"); |
| } |
| |
| if (old_lb_policy != NULL) { |
| grpc_pollset_set_del_pollset_set( |
| exec_ctx, old_lb_policy->interested_parties, chand->interested_parties); |
| GRPC_LB_POLICY_UNREF(exec_ctx, old_lb_policy, "channel"); |
| } |
| |
| if (lb_policy != NULL) { |
| GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "config_change"); |
| } |
| |
| GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->owning_stack, "resolver"); |
| GRPC_ERROR_UNREF(state_error); |
| } |
| |
| static void start_transport_op_locked(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error_ignored) { |
| grpc_transport_op *op = arg; |
| grpc_channel_element *elem = op->handler_private.extra_arg; |
| channel_data *chand = elem->channel_data; |
| |
| if (op->on_connectivity_state_change != NULL) { |
| grpc_connectivity_state_notify_on_state_change( |
| exec_ctx, &chand->state_tracker, op->connectivity_state, |
| op->on_connectivity_state_change); |
| op->on_connectivity_state_change = NULL; |
| op->connectivity_state = NULL; |
| } |
| |
| if (op->send_ping != NULL) { |
| if (chand->lb_policy == NULL) { |
| grpc_closure_sched( |
| exec_ctx, op->send_ping, |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("Ping with no load balancing")); |
| } else { |
| grpc_lb_policy_ping_one_locked(exec_ctx, chand->lb_policy, op->send_ping); |
| op->bind_pollset = NULL; |
| } |
| op->send_ping = NULL; |
| } |
| |
| if (op->disconnect_with_error != GRPC_ERROR_NONE) { |
| if (chand->resolver != NULL) { |
| set_channel_connectivity_state_locked( |
| exec_ctx, chand, GRPC_CHANNEL_SHUTDOWN, |
| GRPC_ERROR_REF(op->disconnect_with_error), "disconnect"); |
| grpc_resolver_shutdown_locked(exec_ctx, chand->resolver); |
| GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel"); |
| chand->resolver = NULL; |
| if (!chand->started_resolving) { |
| grpc_closure_list_fail_all(&chand->waiting_for_config_closures, |
| GRPC_ERROR_REF(op->disconnect_with_error)); |
| grpc_closure_list_sched(exec_ctx, &chand->waiting_for_config_closures); |
| } |
| if (chand->lb_policy != NULL) { |
| grpc_pollset_set_del_pollset_set(exec_ctx, |
| chand->lb_policy->interested_parties, |
| chand->interested_parties); |
| GRPC_LB_POLICY_UNREF(exec_ctx, chand->lb_policy, "channel"); |
| chand->lb_policy = NULL; |
| } |
| } |
| GRPC_ERROR_UNREF(op->disconnect_with_error); |
| } |
| GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->owning_stack, "start_transport_op"); |
| |
| grpc_closure_sched(exec_ctx, op->on_consumed, GRPC_ERROR_NONE); |
| } |
| |
| static void cc_start_transport_op(grpc_exec_ctx *exec_ctx, |
| grpc_channel_element *elem, |
| grpc_transport_op *op) { |
| channel_data *chand = elem->channel_data; |
| |
| GPR_ASSERT(op->set_accept_stream == false); |
| if (op->bind_pollset != NULL) { |
| grpc_pollset_set_add_pollset(exec_ctx, chand->interested_parties, |
| op->bind_pollset); |
| } |
| |
| op->handler_private.extra_arg = elem; |
| GRPC_CHANNEL_STACK_REF(chand->owning_stack, "start_transport_op"); |
| grpc_closure_sched( |
| exec_ctx, |
| grpc_closure_init(&op->handler_private.closure, start_transport_op_locked, |
| op, grpc_combiner_scheduler(chand->combiner, false)), |
| GRPC_ERROR_NONE); |
| } |
| |
| static void cc_get_channel_info(grpc_exec_ctx *exec_ctx, |
| grpc_channel_element *elem, |
| const grpc_channel_info *info) { |
| channel_data *chand = elem->channel_data; |
| gpr_mu_lock(&chand->info_mu); |
| if (info->lb_policy_name != NULL) { |
| *info->lb_policy_name = chand->info_lb_policy_name == NULL |
| ? NULL |
| : gpr_strdup(chand->info_lb_policy_name); |
| } |
| if (info->service_config_json != NULL) { |
| *info->service_config_json = |
| chand->info_service_config_json == NULL |
| ? NULL |
| : gpr_strdup(chand->info_service_config_json); |
| } |
| gpr_mu_unlock(&chand->info_mu); |
| } |
| |
| /* Constructor for channel_data */ |
| static grpc_error *cc_init_channel_elem(grpc_exec_ctx *exec_ctx, |
| grpc_channel_element *elem, |
| grpc_channel_element_args *args) { |
| channel_data *chand = elem->channel_data; |
| GPR_ASSERT(args->is_last); |
| GPR_ASSERT(elem->filter == &grpc_client_channel_filter); |
| // Initialize data members. |
| chand->combiner = grpc_combiner_create(NULL); |
| gpr_mu_init(&chand->info_mu); |
| chand->owning_stack = args->channel_stack; |
| grpc_closure_init(&chand->on_resolver_result_changed, |
| on_resolver_result_changed_locked, chand, |
| grpc_combiner_scheduler(chand->combiner, false)); |
| chand->interested_parties = grpc_pollset_set_create(); |
| grpc_connectivity_state_init(&chand->state_tracker, GRPC_CHANNEL_IDLE, |
| "client_channel"); |
| // Record client channel factory. |
| const grpc_arg *arg = grpc_channel_args_find(args->channel_args, |
| GRPC_ARG_CLIENT_CHANNEL_FACTORY); |
| if (arg == NULL) { |
| return GRPC_ERROR_CREATE_FROM_STATIC_STRING( |
| "Missing client channel factory in args for client channel filter"); |
| } |
| if (arg->type != GRPC_ARG_POINTER) { |
| return GRPC_ERROR_CREATE_FROM_STATIC_STRING( |
| "client channel factory arg must be a pointer"); |
| } |
| grpc_client_channel_factory_ref(arg->value.pointer.p); |
| chand->client_channel_factory = arg->value.pointer.p; |
| // Get server name to resolve, using proxy mapper if needed. |
| arg = grpc_channel_args_find(args->channel_args, GRPC_ARG_SERVER_URI); |
| if (arg == NULL) { |
| return GRPC_ERROR_CREATE_FROM_STATIC_STRING( |
| "Missing server uri in args for client channel filter"); |
| } |
| if (arg->type != GRPC_ARG_STRING) { |
| return GRPC_ERROR_CREATE_FROM_STATIC_STRING( |
| "server uri arg must be a string"); |
| } |
| char *proxy_name = NULL; |
| grpc_channel_args *new_args = NULL; |
| grpc_proxy_mappers_map_name(exec_ctx, arg->value.string, args->channel_args, |
| &proxy_name, &new_args); |
| // Instantiate resolver. |
| chand->resolver = grpc_resolver_create( |
| exec_ctx, proxy_name != NULL ? proxy_name : arg->value.string, |
| new_args != NULL ? new_args : args->channel_args, |
| chand->interested_parties, chand->combiner); |
| if (proxy_name != NULL) gpr_free(proxy_name); |
| if (new_args != NULL) grpc_channel_args_destroy(exec_ctx, new_args); |
| if (chand->resolver == NULL) { |
| return GRPC_ERROR_CREATE_FROM_STATIC_STRING("resolver creation failed"); |
| } |
| chand->deadline_checking_enabled = |
| grpc_deadline_checking_enabled(args->channel_args); |
| return GRPC_ERROR_NONE; |
| } |
| |
| static void shutdown_resolver_locked(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| grpc_resolver *resolver = arg; |
| grpc_resolver_shutdown_locked(exec_ctx, resolver); |
| GRPC_RESOLVER_UNREF(exec_ctx, resolver, "channel"); |
| } |
| |
| /* Destructor for channel_data */ |
| static void cc_destroy_channel_elem(grpc_exec_ctx *exec_ctx, |
| grpc_channel_element *elem) { |
| channel_data *chand = elem->channel_data; |
| if (chand->resolver != NULL) { |
| grpc_closure_sched( |
| exec_ctx, |
| grpc_closure_create(shutdown_resolver_locked, chand->resolver, |
| grpc_combiner_scheduler(chand->combiner, false)), |
| GRPC_ERROR_NONE); |
| } |
| if (chand->client_channel_factory != NULL) { |
| grpc_client_channel_factory_unref(exec_ctx, chand->client_channel_factory); |
| } |
| if (chand->lb_policy != NULL) { |
| grpc_pollset_set_del_pollset_set(exec_ctx, |
| chand->lb_policy->interested_parties, |
| chand->interested_parties); |
| GRPC_LB_POLICY_UNREF(exec_ctx, chand->lb_policy, "channel"); |
| } |
| gpr_free(chand->info_lb_policy_name); |
| gpr_free(chand->info_service_config_json); |
| if (chand->retry_throttle_data != NULL) { |
| grpc_server_retry_throttle_data_unref(chand->retry_throttle_data); |
| } |
| if (chand->method_params_table != NULL) { |
| grpc_slice_hash_table_unref(exec_ctx, chand->method_params_table); |
| } |
| grpc_connectivity_state_destroy(exec_ctx, &chand->state_tracker); |
| grpc_pollset_set_destroy(exec_ctx, chand->interested_parties); |
| GRPC_COMBINER_UNREF(exec_ctx, chand->combiner, "client_channel"); |
| gpr_mu_destroy(&chand->info_mu); |
| } |
| |
| /************************************************************************* |
| * PER-CALL FUNCTIONS |
| */ |
| |
| #define GET_CALL(call_data) \ |
| ((grpc_subchannel_call *)(gpr_atm_acq_load(&(call_data)->subchannel_call))) |
| |
| #define CANCELLED_CALL ((grpc_subchannel_call *)1) |
| |
| typedef enum { |
| /* zero so that it can be default-initialized */ |
| GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING = 0, |
| GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL |
| } subchannel_creation_phase; |
| |
| /** Call data. Holds a pointer to grpc_subchannel_call and the |
| associated machinery to create such a pointer. |
| Handles queueing of stream ops until a call object is ready, waiting |
| for initial metadata before trying to create a call object, |
| and handling cancellation gracefully. */ |
| typedef struct client_channel_call_data { |
| // State for handling deadlines. |
| // The code in deadline_filter.c requires this to be the first field. |
| // TODO(roth): This is slightly sub-optimal in that grpc_deadline_state |
| // and this struct both independently store a pointer to the call |
| // stack and each has its own mutex. If/when we have time, find a way |
| // to avoid this without breaking the grpc_deadline_state abstraction. |
| grpc_deadline_state deadline_state; |
| |
| grpc_slice path; // Request path. |
| gpr_timespec call_start_time; |
| gpr_timespec deadline; |
| grpc_server_retry_throttle_data *retry_throttle_data; |
| method_parameters *method_params; |
| |
| grpc_error *cancel_error; |
| |
| /** either 0 for no call, 1 for cancelled, or a pointer to a |
| grpc_subchannel_call */ |
| gpr_atm subchannel_call; |
| gpr_arena *arena; |
| |
| subchannel_creation_phase creation_phase; |
| grpc_connected_subchannel *connected_subchannel; |
| grpc_polling_entity *pollent; |
| |
| grpc_transport_stream_op_batch **waiting_ops; |
| size_t waiting_ops_count; |
| size_t waiting_ops_capacity; |
| |
| grpc_closure next_step; |
| |
| grpc_call_stack *owning_call; |
| |
| grpc_linked_mdelem lb_token_mdelem; |
| |
| grpc_closure on_complete; |
| grpc_closure *original_on_complete; |
| } call_data; |
| |
| grpc_subchannel_call *grpc_client_channel_get_subchannel_call( |
| grpc_call_element *call_elem) { |
| grpc_subchannel_call *scc = GET_CALL((call_data *)call_elem->call_data); |
| return scc == CANCELLED_CALL ? NULL : scc; |
| } |
| |
| static void add_waiting_locked(call_data *calld, |
| grpc_transport_stream_op_batch *op) { |
| GPR_TIMER_BEGIN("add_waiting_locked", 0); |
| if (calld->waiting_ops_count == calld->waiting_ops_capacity) { |
| calld->waiting_ops_capacity = GPR_MAX(3, 2 * calld->waiting_ops_capacity); |
| calld->waiting_ops = |
| gpr_realloc(calld->waiting_ops, |
| calld->waiting_ops_capacity * sizeof(*calld->waiting_ops)); |
| } |
| calld->waiting_ops[calld->waiting_ops_count++] = op; |
| GPR_TIMER_END("add_waiting_locked", 0); |
| } |
| |
| static void fail_locked(grpc_exec_ctx *exec_ctx, call_data *calld, |
| grpc_error *error) { |
| size_t i; |
| for (i = 0; i < calld->waiting_ops_count; i++) { |
| grpc_transport_stream_op_batch_finish_with_failure( |
| exec_ctx, calld->waiting_ops[i], GRPC_ERROR_REF(error)); |
| } |
| calld->waiting_ops_count = 0; |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void retry_waiting_locked(grpc_exec_ctx *exec_ctx, call_data *calld) { |
| if (calld->waiting_ops_count == 0) { |
| return; |
| } |
| |
| grpc_subchannel_call *call = GET_CALL(calld); |
| grpc_transport_stream_op_batch **ops = calld->waiting_ops; |
| size_t nops = calld->waiting_ops_count; |
| if (call == CANCELLED_CALL) { |
| fail_locked(exec_ctx, calld, GRPC_ERROR_CANCELLED); |
| return; |
| } |
| calld->waiting_ops = NULL; |
| calld->waiting_ops_count = 0; |
| calld->waiting_ops_capacity = 0; |
| for (size_t i = 0; i < nops; i++) { |
| grpc_subchannel_call_process_op(exec_ctx, call, ops[i]); |
| } |
| gpr_free(ops); |
| } |
| |
| // Sets calld->method_params and calld->retry_throttle_data. |
| // If the method params specify a timeout, populates |
| // *per_method_deadline and returns true. |
| static bool set_call_method_params_from_service_config_locked( |
| grpc_exec_ctx *exec_ctx, grpc_call_element *elem, |
| gpr_timespec *per_method_deadline) { |
| channel_data *chand = elem->channel_data; |
| call_data *calld = elem->call_data; |
| if (chand->retry_throttle_data != NULL) { |
| calld->retry_throttle_data = |
| grpc_server_retry_throttle_data_ref(chand->retry_throttle_data); |
| } |
| if (chand->method_params_table != NULL) { |
| calld->method_params = grpc_method_config_table_get( |
| exec_ctx, chand->method_params_table, calld->path); |
| if (calld->method_params != NULL) { |
| method_parameters_ref(calld->method_params); |
| if (gpr_time_cmp(calld->method_params->timeout, |
| gpr_time_0(GPR_TIMESPAN)) != 0) { |
| *per_method_deadline = |
| gpr_time_add(calld->call_start_time, calld->method_params->timeout); |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| static void apply_final_configuration_locked(grpc_exec_ctx *exec_ctx, |
| grpc_call_element *elem) { |
| /* apply service-config level configuration to the call (now that we're |
| * certain it exists) */ |
| call_data *calld = elem->call_data; |
| channel_data *chand = elem->channel_data; |
| gpr_timespec per_method_deadline; |
| if (set_call_method_params_from_service_config_locked(exec_ctx, elem, |
| &per_method_deadline)) { |
| // If the deadline from the service config is shorter than the one |
| // from the client API, reset the deadline timer. |
| if (chand->deadline_checking_enabled && |
| gpr_time_cmp(per_method_deadline, calld->deadline) < 0) { |
| calld->deadline = per_method_deadline; |
| grpc_deadline_state_reset(exec_ctx, elem, calld->deadline); |
| } |
| } |
| } |
| |
| static void subchannel_ready_locked(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| grpc_call_element *elem = arg; |
| call_data *calld = elem->call_data; |
| channel_data *chand = elem->channel_data; |
| GPR_ASSERT(calld->creation_phase == |
| GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL); |
| grpc_polling_entity_del_from_pollset_set(exec_ctx, calld->pollent, |
| chand->interested_parties); |
| calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING; |
| if (calld->connected_subchannel == NULL) { |
| gpr_atm_no_barrier_store(&calld->subchannel_call, 1); |
| fail_locked(exec_ctx, calld, |
| GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( |
| "Failed to create subchannel", &error, 1)); |
| } else if (GET_CALL(calld) == CANCELLED_CALL) { |
| /* already cancelled before subchannel became ready */ |
| grpc_error *cancellation_error = |
| GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( |
| "Cancelled before creating subchannel", &error, 1); |
| /* if due to deadline, attach the deadline exceeded status to the error */ |
| if (gpr_time_cmp(calld->deadline, gpr_now(GPR_CLOCK_MONOTONIC)) < 0) { |
| cancellation_error = |
| grpc_error_set_int(cancellation_error, GRPC_ERROR_INT_GRPC_STATUS, |
| GRPC_STATUS_DEADLINE_EXCEEDED); |
| } |
| fail_locked(exec_ctx, calld, cancellation_error); |
| } else { |
| /* Create call on subchannel. */ |
| grpc_subchannel_call *subchannel_call = NULL; |
| const grpc_connected_subchannel_call_args call_args = { |
| .pollent = calld->pollent, |
| .path = calld->path, |
| .start_time = calld->call_start_time, |
| .deadline = calld->deadline, |
| .arena = calld->arena}; |
| grpc_error *new_error = grpc_connected_subchannel_create_call( |
| exec_ctx, calld->connected_subchannel, &call_args, &subchannel_call); |
| gpr_atm_rel_store(&calld->subchannel_call, |
| (gpr_atm)(uintptr_t)subchannel_call); |
| if (new_error != GRPC_ERROR_NONE) { |
| new_error = grpc_error_add_child(new_error, error); |
| fail_locked(exec_ctx, calld, new_error); |
| } else { |
| retry_waiting_locked(exec_ctx, calld); |
| } |
| } |
| GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, "pick_subchannel"); |
| } |
| |
| static char *cc_get_peer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) { |
| call_data *calld = elem->call_data; |
| grpc_subchannel_call *subchannel_call = GET_CALL(calld); |
| if (subchannel_call == NULL || subchannel_call == CANCELLED_CALL) { |
| return NULL; |
| } else { |
| return grpc_subchannel_call_get_peer(exec_ctx, subchannel_call); |
| } |
| } |
| |
| typedef struct { |
| grpc_metadata_batch *initial_metadata; |
| uint32_t initial_metadata_flags; |
| grpc_connected_subchannel **connected_subchannel; |
| grpc_closure *on_ready; |
| grpc_call_element *elem; |
| grpc_closure closure; |
| } continue_picking_args; |
| |
| /** Return true if subchannel is available immediately (in which case on_ready |
| should not be called), or false otherwise (in which case on_ready should be |
| called when the subchannel is available). */ |
| static bool pick_subchannel_locked( |
| grpc_exec_ctx *exec_ctx, grpc_call_element *elem, |
| grpc_metadata_batch *initial_metadata, uint32_t initial_metadata_flags, |
| grpc_connected_subchannel **connected_subchannel, grpc_closure *on_ready, |
| grpc_error *error); |
| |
| static void continue_picking_locked(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| continue_picking_args *cpa = arg; |
| if (cpa->connected_subchannel == NULL) { |
| /* cancelled, do nothing */ |
| } else if (error != GRPC_ERROR_NONE) { |
| grpc_closure_sched(exec_ctx, cpa->on_ready, GRPC_ERROR_REF(error)); |
| } else { |
| if (pick_subchannel_locked(exec_ctx, cpa->elem, cpa->initial_metadata, |
| cpa->initial_metadata_flags, |
| cpa->connected_subchannel, cpa->on_ready, |
| GRPC_ERROR_NONE)) { |
| grpc_closure_sched(exec_ctx, cpa->on_ready, GRPC_ERROR_NONE); |
| } |
| } |
| gpr_free(cpa); |
| } |
| |
| static bool pick_subchannel_locked( |
| grpc_exec_ctx *exec_ctx, grpc_call_element *elem, |
| grpc_metadata_batch *initial_metadata, uint32_t initial_metadata_flags, |
| grpc_connected_subchannel **connected_subchannel, grpc_closure *on_ready, |
| grpc_error *error) { |
| GPR_TIMER_BEGIN("pick_subchannel", 0); |
| |
| channel_data *chand = elem->channel_data; |
| call_data *calld = elem->call_data; |
| continue_picking_args *cpa; |
| grpc_closure *closure; |
| |
| GPR_ASSERT(connected_subchannel); |
| |
| if (initial_metadata == NULL) { |
| if (chand->lb_policy != NULL) { |
| grpc_lb_policy_cancel_pick_locked(exec_ctx, chand->lb_policy, |
| connected_subchannel, |
| GRPC_ERROR_REF(error)); |
| } |
| for (closure = chand->waiting_for_config_closures.head; closure != NULL; |
| closure = closure->next_data.next) { |
| cpa = closure->cb_arg; |
| if (cpa->connected_subchannel == connected_subchannel) { |
| cpa->connected_subchannel = NULL; |
| grpc_closure_sched(exec_ctx, cpa->on_ready, |
| GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( |
| "Pick cancelled", &error, 1)); |
| } |
| } |
| GPR_TIMER_END("pick_subchannel", 0); |
| GRPC_ERROR_UNREF(error); |
| return true; |
| } |
| GPR_ASSERT(error == GRPC_ERROR_NONE); |
| if (chand->lb_policy != NULL) { |
| apply_final_configuration_locked(exec_ctx, elem); |
| grpc_lb_policy *lb_policy = chand->lb_policy; |
| GRPC_LB_POLICY_REF(lb_policy, "pick_subchannel"); |
| // If the application explicitly set wait_for_ready, use that. |
| // Otherwise, if the service config specified a value for this |
| // method, use that. |
| const bool wait_for_ready_set_from_api = |
| initial_metadata_flags & |
| GRPC_INITIAL_METADATA_WAIT_FOR_READY_EXPLICITLY_SET; |
| const bool wait_for_ready_set_from_service_config = |
| calld->method_params != NULL && |
| calld->method_params->wait_for_ready != WAIT_FOR_READY_UNSET; |
| if (!wait_for_ready_set_from_api && |
| wait_for_ready_set_from_service_config) { |
| if (calld->method_params->wait_for_ready == WAIT_FOR_READY_TRUE) { |
| initial_metadata_flags |= GRPC_INITIAL_METADATA_WAIT_FOR_READY; |
| } else { |
| initial_metadata_flags &= ~GRPC_INITIAL_METADATA_WAIT_FOR_READY; |
| } |
| } |
| const grpc_lb_policy_pick_args inputs = { |
| initial_metadata, initial_metadata_flags, &calld->lb_token_mdelem, |
| gpr_inf_future(GPR_CLOCK_MONOTONIC)}; |
| |
| // Wrap the user-provided callback in order to hold a strong reference to |
| // the LB policy for the duration of the pick. |
| wrapped_on_pick_closure_arg *w_on_pick_arg = |
| gpr_zalloc(sizeof(*w_on_pick_arg)); |
| grpc_closure_init(&w_on_pick_arg->wrapper_closure, |
| wrapped_on_pick_closure_cb, w_on_pick_arg, |
| grpc_schedule_on_exec_ctx); |
| w_on_pick_arg->wrapped_closure = on_ready; |
| GRPC_LB_POLICY_REF(lb_policy, "pick_subchannel_wrapping"); |
| w_on_pick_arg->lb_policy = lb_policy; |
| const bool pick_done = grpc_lb_policy_pick_locked( |
| exec_ctx, lb_policy, &inputs, connected_subchannel, NULL, |
| &w_on_pick_arg->wrapper_closure); |
| if (pick_done) { |
| /* synchronous grpc_lb_policy_pick call. Unref the LB policy. */ |
| GRPC_LB_POLICY_UNREF(exec_ctx, w_on_pick_arg->lb_policy, |
| "pick_subchannel_wrapping"); |
| gpr_free(w_on_pick_arg); |
| } |
| GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "pick_subchannel"); |
| GPR_TIMER_END("pick_subchannel", 0); |
| return pick_done; |
| } |
| if (chand->resolver != NULL && !chand->started_resolving) { |
| chand->started_resolving = true; |
| GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver"); |
| grpc_resolver_next_locked(exec_ctx, chand->resolver, |
| &chand->resolver_result, |
| &chand->on_resolver_result_changed); |
| } |
| if (chand->resolver != NULL) { |
| cpa = gpr_malloc(sizeof(*cpa)); |
| cpa->initial_metadata = initial_metadata; |
| cpa->initial_metadata_flags = initial_metadata_flags; |
| cpa->connected_subchannel = connected_subchannel; |
| cpa->on_ready = on_ready; |
| cpa->elem = elem; |
| grpc_closure_init(&cpa->closure, continue_picking_locked, cpa, |
| grpc_combiner_scheduler(chand->combiner, true)); |
| grpc_closure_list_append(&chand->waiting_for_config_closures, &cpa->closure, |
| GRPC_ERROR_NONE); |
| } else { |
| grpc_closure_sched(exec_ctx, on_ready, |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("Disconnected")); |
| } |
| |
| GPR_TIMER_END("pick_subchannel", 0); |
| return false; |
| } |
| |
| static void start_transport_stream_op_batch_locked_inner( |
| grpc_exec_ctx *exec_ctx, grpc_transport_stream_op_batch *op, |
| grpc_call_element *elem) { |
| channel_data *chand = elem->channel_data; |
| call_data *calld = elem->call_data; |
| grpc_subchannel_call *call; |
| |
| /* need to recheck that another thread hasn't set the call */ |
| call = GET_CALL(calld); |
| if (call == CANCELLED_CALL) { |
| grpc_transport_stream_op_batch_finish_with_failure( |
| exec_ctx, op, GRPC_ERROR_REF(calld->cancel_error)); |
| /* early out */ |
| return; |
| } |
| if (call != NULL) { |
| grpc_subchannel_call_process_op(exec_ctx, call, op); |
| /* early out */ |
| return; |
| } |
| /* if this is a cancellation, then we can raise our cancelled flag */ |
| if (op->cancel_stream) { |
| if (!gpr_atm_rel_cas(&calld->subchannel_call, 0, |
| (gpr_atm)(uintptr_t)CANCELLED_CALL)) { |
| /* recurse to retry */ |
| start_transport_stream_op_batch_locked_inner(exec_ctx, op, elem); |
| /* early out */ |
| return; |
| } else { |
| /* Stash a copy of cancel_error in our call data, so that we can use |
| it for subsequent operations. This ensures that if the call is |
| cancelled before any ops are passed down (e.g., if the deadline |
| is in the past when the call starts), we can return the right |
| error to the caller when the first op does get passed down. */ |
| calld->cancel_error = |
| GRPC_ERROR_REF(op->payload->cancel_stream.cancel_error); |
| switch (calld->creation_phase) { |
| case GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING: |
| fail_locked(exec_ctx, calld, |
| GRPC_ERROR_REF(op->payload->cancel_stream.cancel_error)); |
| break; |
| case GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL: |
| pick_subchannel_locked( |
| exec_ctx, elem, NULL, 0, &calld->connected_subchannel, NULL, |
| GRPC_ERROR_REF(op->payload->cancel_stream.cancel_error)); |
| break; |
| } |
| grpc_transport_stream_op_batch_finish_with_failure( |
| exec_ctx, op, |
| GRPC_ERROR_REF(op->payload->cancel_stream.cancel_error)); |
| /* early out */ |
| return; |
| } |
| } |
| /* if we don't have a subchannel, try to get one */ |
| if (calld->creation_phase == GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING && |
| calld->connected_subchannel == NULL && op->send_initial_metadata) { |
| calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL; |
| grpc_closure_init(&calld->next_step, subchannel_ready_locked, elem, |
| grpc_combiner_scheduler(chand->combiner, true)); |
| GRPC_CALL_STACK_REF(calld->owning_call, "pick_subchannel"); |
| /* If a subchannel is not available immediately, the polling entity from |
| call_data should be provided to channel_data's interested_parties, so |
| that IO of the lb_policy and resolver could be done under it. */ |
| if (pick_subchannel_locked( |
| exec_ctx, elem, |
| op->payload->send_initial_metadata.send_initial_metadata, |
| op->payload->send_initial_metadata.send_initial_metadata_flags, |
| &calld->connected_subchannel, &calld->next_step, GRPC_ERROR_NONE)) { |
| calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING; |
| GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, "pick_subchannel"); |
| } else { |
| grpc_polling_entity_add_to_pollset_set(exec_ctx, calld->pollent, |
| chand->interested_parties); |
| } |
| } |
| /* if we've got a subchannel, then let's ask it to create a call */ |
| if (calld->creation_phase == GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING && |
| calld->connected_subchannel != NULL) { |
| grpc_subchannel_call *subchannel_call = NULL; |
| const grpc_connected_subchannel_call_args call_args = { |
| .pollent = calld->pollent, |
| .path = calld->path, |
| .start_time = calld->call_start_time, |
| .deadline = calld->deadline, |
| .arena = calld->arena}; |
| grpc_error *error = grpc_connected_subchannel_create_call( |
| exec_ctx, calld->connected_subchannel, &call_args, &subchannel_call); |
| gpr_atm_rel_store(&calld->subchannel_call, |
| (gpr_atm)(uintptr_t)subchannel_call); |
| if (error != GRPC_ERROR_NONE) { |
| fail_locked(exec_ctx, calld, GRPC_ERROR_REF(error)); |
| grpc_transport_stream_op_batch_finish_with_failure(exec_ctx, op, error); |
| } else { |
| retry_waiting_locked(exec_ctx, calld); |
| /* recurse to retry */ |
| start_transport_stream_op_batch_locked_inner(exec_ctx, op, elem); |
| } |
| /* early out */ |
| return; |
| } |
| /* nothing to be done but wait */ |
| add_waiting_locked(calld, op); |
| } |
| |
| static void on_complete(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) { |
| grpc_call_element *elem = arg; |
| call_data *calld = elem->call_data; |
| if (calld->retry_throttle_data != NULL) { |
| if (error == GRPC_ERROR_NONE) { |
| grpc_server_retry_throttle_data_record_success( |
| calld->retry_throttle_data); |
| } else { |
| // TODO(roth): In a subsequent PR, check the return value here and |
| // decide whether or not to retry. Note that we should only |
| // record failures whose statuses match the configured retryable |
| // or non-fatal status codes. |
| grpc_server_retry_throttle_data_record_failure( |
| calld->retry_throttle_data); |
| } |
| } |
| grpc_closure_run(exec_ctx, calld->original_on_complete, |
| GRPC_ERROR_REF(error)); |
| } |
| |
| static void start_transport_stream_op_batch_locked(grpc_exec_ctx *exec_ctx, |
| void *arg, |
| grpc_error *error_ignored) { |
| GPR_TIMER_BEGIN("start_transport_stream_op_batch_locked", 0); |
| |
| grpc_transport_stream_op_batch *op = arg; |
| grpc_call_element *elem = op->handler_private.extra_arg; |
| call_data *calld = elem->call_data; |
| |
| if (op->recv_trailing_metadata) { |
| GPR_ASSERT(op->on_complete != NULL); |
| calld->original_on_complete = op->on_complete; |
| grpc_closure_init(&calld->on_complete, on_complete, elem, |
| grpc_schedule_on_exec_ctx); |
| op->on_complete = &calld->on_complete; |
| } |
| |
| start_transport_stream_op_batch_locked_inner(exec_ctx, op, elem); |
| |
| GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, |
| "start_transport_stream_op_batch"); |
| GPR_TIMER_END("start_transport_stream_op_batch_locked", 0); |
| } |
| |
| /* The logic here is fairly complicated, due to (a) the fact that we |
| need to handle the case where we receive the send op before the |
| initial metadata op, and (b) the need for efficiency, especially in |
| the streaming case. |
| |
| We use double-checked locking to initially see if initialization has been |
| performed. If it has not, we acquire the combiner and perform initialization. |
| If it has, we proceed on the fast path. */ |
| static void cc_start_transport_stream_op_batch( |
| grpc_exec_ctx *exec_ctx, grpc_call_element *elem, |
| grpc_transport_stream_op_batch *op) { |
| call_data *calld = elem->call_data; |
| channel_data *chand = elem->channel_data; |
| GRPC_CALL_LOG_OP(GPR_INFO, elem, op); |
| if (chand->deadline_checking_enabled) { |
| grpc_deadline_state_client_start_transport_stream_op_batch(exec_ctx, elem, |
| op); |
| } |
| /* try to (atomically) get the call */ |
| grpc_subchannel_call *call = GET_CALL(calld); |
| GPR_TIMER_BEGIN("cc_start_transport_stream_op_batch", 0); |
| if (call == CANCELLED_CALL) { |
| grpc_transport_stream_op_batch_finish_with_failure( |
| exec_ctx, op, GRPC_ERROR_REF(calld->cancel_error)); |
| GPR_TIMER_END("cc_start_transport_stream_op_batch", 0); |
| /* early out */ |
| return; |
| } |
| if (call != NULL) { |
| grpc_subchannel_call_process_op(exec_ctx, call, op); |
| GPR_TIMER_END("cc_start_transport_stream_op_batch", 0); |
| /* early out */ |
| return; |
| } |
| /* we failed; lock and figure out what to do */ |
| GRPC_CALL_STACK_REF(calld->owning_call, "start_transport_stream_op_batch"); |
| op->handler_private.extra_arg = elem; |
| grpc_closure_sched( |
| exec_ctx, |
| grpc_closure_init(&op->handler_private.closure, |
| start_transport_stream_op_batch_locked, op, |
| grpc_combiner_scheduler(chand->combiner, false)), |
| GRPC_ERROR_NONE); |
| GPR_TIMER_END("cc_start_transport_stream_op_batch", 0); |
| } |
| |
| /* Constructor for call_data */ |
| static grpc_error *cc_init_call_elem(grpc_exec_ctx *exec_ctx, |
| grpc_call_element *elem, |
| const grpc_call_element_args *args) { |
| call_data *calld = elem->call_data; |
| channel_data *chand = elem->channel_data; |
| // Initialize data members. |
| calld->path = grpc_slice_ref_internal(args->path); |
| calld->call_start_time = args->start_time; |
| calld->deadline = gpr_convert_clock_type(args->deadline, GPR_CLOCK_MONOTONIC); |
| calld->owning_call = args->call_stack; |
| calld->arena = args->arena; |
| if (chand->deadline_checking_enabled) { |
| grpc_deadline_state_init(exec_ctx, elem, args->call_stack, calld->deadline); |
| } |
| return GRPC_ERROR_NONE; |
| } |
| |
| /* Destructor for call_data */ |
| static void cc_destroy_call_elem(grpc_exec_ctx *exec_ctx, |
| grpc_call_element *elem, |
| const grpc_call_final_info *final_info, |
| grpc_closure *then_schedule_closure) { |
| call_data *calld = elem->call_data; |
| channel_data *chand = elem->channel_data; |
| if (chand->deadline_checking_enabled) { |
| grpc_deadline_state_destroy(exec_ctx, elem); |
| } |
| grpc_slice_unref_internal(exec_ctx, calld->path); |
| if (calld->method_params != NULL) { |
| method_parameters_unref(calld->method_params); |
| } |
| GRPC_ERROR_UNREF(calld->cancel_error); |
| grpc_subchannel_call *call = GET_CALL(calld); |
| if (call != NULL && call != CANCELLED_CALL) { |
| grpc_subchannel_call_set_cleanup_closure(call, then_schedule_closure); |
| then_schedule_closure = NULL; |
| GRPC_SUBCHANNEL_CALL_UNREF(exec_ctx, call, "client_channel_destroy_call"); |
| } |
| GPR_ASSERT(calld->creation_phase == GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING); |
| GPR_ASSERT(calld->waiting_ops_count == 0); |
| if (calld->connected_subchannel != NULL) { |
| GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, calld->connected_subchannel, |
| "picked"); |
| } |
| gpr_free(calld->waiting_ops); |
| grpc_closure_sched(exec_ctx, then_schedule_closure, GRPC_ERROR_NONE); |
| } |
| |
| static void cc_set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx, |
| grpc_call_element *elem, |
| grpc_polling_entity *pollent) { |
| call_data *calld = elem->call_data; |
| calld->pollent = pollent; |
| } |
| |
| /************************************************************************* |
| * EXPORTED SYMBOLS |
| */ |
| |
| const grpc_channel_filter grpc_client_channel_filter = { |
| cc_start_transport_stream_op_batch, |
| cc_start_transport_op, |
| sizeof(call_data), |
| cc_init_call_elem, |
| cc_set_pollset_or_pollset_set, |
| cc_destroy_call_elem, |
| sizeof(channel_data), |
| cc_init_channel_elem, |
| cc_destroy_channel_elem, |
| cc_get_peer, |
| cc_get_channel_info, |
| "client-channel", |
| }; |
| |
| static void try_to_connect_locked(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error_ignored) { |
| channel_data *chand = arg; |
| if (chand->lb_policy != NULL) { |
| grpc_lb_policy_exit_idle_locked(exec_ctx, chand->lb_policy); |
| } else { |
| chand->exit_idle_when_lb_policy_arrives = true; |
| if (!chand->started_resolving && chand->resolver != NULL) { |
| GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver"); |
| chand->started_resolving = true; |
| grpc_resolver_next_locked(exec_ctx, chand->resolver, |
| &chand->resolver_result, |
| &chand->on_resolver_result_changed); |
| } |
| } |
| GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->owning_stack, "try_to_connect"); |
| } |
| |
| grpc_connectivity_state grpc_client_channel_check_connectivity_state( |
| grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, int try_to_connect) { |
| channel_data *chand = elem->channel_data; |
| grpc_connectivity_state out = |
| grpc_connectivity_state_check(&chand->state_tracker); |
| if (out == GRPC_CHANNEL_IDLE && try_to_connect) { |
| GRPC_CHANNEL_STACK_REF(chand->owning_stack, "try_to_connect"); |
| grpc_closure_sched( |
| exec_ctx, |
| grpc_closure_create(try_to_connect_locked, chand, |
| grpc_combiner_scheduler(chand->combiner, false)), |
| GRPC_ERROR_NONE); |
| } |
| return out; |
| } |
| |
| typedef struct { |
| channel_data *chand; |
| grpc_pollset *pollset; |
| grpc_closure *on_complete; |
| grpc_connectivity_state *state; |
| grpc_closure my_closure; |
| } external_connectivity_watcher; |
| |
| static void on_external_watch_complete(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| external_connectivity_watcher *w = arg; |
| grpc_closure *follow_up = w->on_complete; |
| grpc_pollset_set_del_pollset(exec_ctx, w->chand->interested_parties, |
| w->pollset); |
| GRPC_CHANNEL_STACK_UNREF(exec_ctx, w->chand->owning_stack, |
| "external_connectivity_watcher"); |
| gpr_free(w); |
| grpc_closure_run(exec_ctx, follow_up, GRPC_ERROR_REF(error)); |
| } |
| |
| static void watch_connectivity_state_locked(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error_ignored) { |
| external_connectivity_watcher *w = arg; |
| grpc_closure_init(&w->my_closure, on_external_watch_complete, w, |
| grpc_schedule_on_exec_ctx); |
| grpc_connectivity_state_notify_on_state_change( |
| exec_ctx, &w->chand->state_tracker, w->state, &w->my_closure); |
| } |
| |
| void grpc_client_channel_watch_connectivity_state( |
| grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, grpc_pollset *pollset, |
| grpc_connectivity_state *state, grpc_closure *on_complete) { |
| channel_data *chand = elem->channel_data; |
| external_connectivity_watcher *w = gpr_malloc(sizeof(*w)); |
| w->chand = chand; |
| w->pollset = pollset; |
| w->on_complete = on_complete; |
| w->state = state; |
| grpc_pollset_set_add_pollset(exec_ctx, chand->interested_parties, pollset); |
| GRPC_CHANNEL_STACK_REF(w->chand->owning_stack, |
| "external_connectivity_watcher"); |
| grpc_closure_sched( |
| exec_ctx, |
| grpc_closure_init(&w->my_closure, watch_connectivity_state_locked, w, |
| grpc_combiner_scheduler(chand->combiner, true)), |
| GRPC_ERROR_NONE); |
| } |