| /* |
| * |
| * Copyright 2015 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| |
| #include "src/core/ext/filters/client_channel/lb_policy/subchannel_list.h" |
| #include "src/core/ext/filters/client_channel/lb_policy_registry.h" |
| #include "src/core/ext/filters/client_channel/subchannel.h" |
| #include "src/core/ext/filters/client_channel/subchannel_index.h" |
| #include "src/core/lib/channel/channel_args.h" |
| #include "src/core/lib/iomgr/combiner.h" |
| #include "src/core/lib/iomgr/sockaddr_utils.h" |
| #include "src/core/lib/transport/connectivity_state.h" |
| |
| grpc_core::TraceFlag grpc_lb_pick_first_trace(false, "pick_first"); |
| |
| typedef struct { |
| /** base policy: must be first */ |
| grpc_lb_policy base; |
| /** all our subchannels */ |
| grpc_lb_subchannel_list* subchannel_list; |
| /** latest pending subchannel list */ |
| grpc_lb_subchannel_list* latest_pending_subchannel_list; |
| /** selected subchannel in \a subchannel_list */ |
| grpc_lb_subchannel_data* selected; |
| /** have we started picking? */ |
| bool started_picking; |
| /** are we shut down? */ |
| bool shutdown; |
| /** list of picks that are waiting on connectivity */ |
| grpc_lb_policy_pick_state* pending_picks; |
| /** our connectivity state tracker */ |
| grpc_connectivity_state_tracker state_tracker; |
| } pick_first_lb_policy; |
| |
| static void pf_destroy(grpc_lb_policy* pol) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)pol; |
| GPR_ASSERT(p->subchannel_list == nullptr); |
| GPR_ASSERT(p->latest_pending_subchannel_list == nullptr); |
| GPR_ASSERT(p->pending_picks == nullptr); |
| grpc_connectivity_state_destroy(&p->state_tracker); |
| gpr_free(p); |
| grpc_subchannel_index_unref(); |
| if (grpc_lb_pick_first_trace.enabled()) { |
| gpr_log(GPR_DEBUG, "Pick First %p destroyed.", (void*)p); |
| } |
| } |
| |
| static void pf_shutdown_locked(grpc_lb_policy* pol, |
| grpc_lb_policy* new_policy) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)pol; |
| grpc_error* error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel shutdown"); |
| if (grpc_lb_pick_first_trace.enabled()) { |
| gpr_log(GPR_DEBUG, "Pick First %p Shutting down", p); |
| } |
| p->shutdown = true; |
| grpc_lb_policy_pick_state* pick; |
| while ((pick = p->pending_picks) != nullptr) { |
| p->pending_picks = pick->next; |
| if (new_policy != nullptr) { |
| // Hand off to new LB policy. |
| if (grpc_lb_policy_pick_locked(new_policy, pick)) { |
| // Synchronous return, schedule closure. |
| GRPC_CLOSURE_SCHED(pick->on_complete, GRPC_ERROR_NONE); |
| } |
| } else { |
| pick->connected_subchannel = nullptr; |
| GRPC_CLOSURE_SCHED(pick->on_complete, GRPC_ERROR_REF(error)); |
| } |
| } |
| grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_SHUTDOWN, |
| GRPC_ERROR_REF(error), "shutdown"); |
| if (p->subchannel_list != nullptr) { |
| grpc_lb_subchannel_list_shutdown_and_unref(p->subchannel_list, |
| "pf_shutdown"); |
| p->subchannel_list = nullptr; |
| } |
| if (p->latest_pending_subchannel_list != nullptr) { |
| grpc_lb_subchannel_list_shutdown_and_unref( |
| p->latest_pending_subchannel_list, "pf_shutdown"); |
| p->latest_pending_subchannel_list = nullptr; |
| } |
| grpc_lb_policy_try_reresolve(&p->base, &grpc_lb_pick_first_trace, |
| GRPC_ERROR_CANCELLED); |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void pf_cancel_pick_locked(grpc_lb_policy* pol, |
| grpc_lb_policy_pick_state* pick, |
| grpc_error* error) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)pol; |
| grpc_lb_policy_pick_state* pp = p->pending_picks; |
| p->pending_picks = nullptr; |
| while (pp != nullptr) { |
| grpc_lb_policy_pick_state* next = pp->next; |
| if (pp == pick) { |
| pick->connected_subchannel = nullptr; |
| GRPC_CLOSURE_SCHED(pick->on_complete, |
| GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( |
| "Pick Cancelled", &error, 1)); |
| } else { |
| pp->next = p->pending_picks; |
| p->pending_picks = pp; |
| } |
| pp = next; |
| } |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void pf_cancel_picks_locked(grpc_lb_policy* pol, |
| uint32_t initial_metadata_flags_mask, |
| uint32_t initial_metadata_flags_eq, |
| grpc_error* error) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)pol; |
| grpc_lb_policy_pick_state* pick = p->pending_picks; |
| p->pending_picks = nullptr; |
| while (pick != nullptr) { |
| grpc_lb_policy_pick_state* next = pick->next; |
| if ((pick->initial_metadata_flags & initial_metadata_flags_mask) == |
| initial_metadata_flags_eq) { |
| GRPC_CLOSURE_SCHED(pick->on_complete, |
| GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( |
| "Pick Cancelled", &error, 1)); |
| } else { |
| pick->next = p->pending_picks; |
| p->pending_picks = pick; |
| } |
| pick = next; |
| } |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void start_picking_locked(pick_first_lb_policy* p) { |
| p->started_picking = true; |
| if (p->subchannel_list != nullptr && |
| p->subchannel_list->num_subchannels > 0) { |
| p->subchannel_list->checking_subchannel = 0; |
| for (size_t i = 0; i < p->subchannel_list->num_subchannels; ++i) { |
| if (p->subchannel_list->subchannels[i].subchannel != nullptr) { |
| grpc_lb_subchannel_list_ref_for_connectivity_watch( |
| p->subchannel_list, "connectivity_watch+start_picking"); |
| grpc_lb_subchannel_data_start_connectivity_watch( |
| &p->subchannel_list->subchannels[i]); |
| break; |
| } |
| } |
| } |
| } |
| |
| static void pf_exit_idle_locked(grpc_lb_policy* pol) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)pol; |
| if (!p->started_picking) { |
| start_picking_locked(p); |
| } |
| } |
| |
| static int pf_pick_locked(grpc_lb_policy* pol, |
| grpc_lb_policy_pick_state* pick) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)pol; |
| // If we have a selected subchannel already, return synchronously. |
| if (p->selected != nullptr) { |
| pick->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF( |
| p->selected->connected_subchannel, "picked"); |
| return 1; |
| } |
| // No subchannel selected yet, so handle asynchronously. |
| if (!p->started_picking) { |
| start_picking_locked(p); |
| } |
| pick->next = p->pending_picks; |
| p->pending_picks = pick; |
| return 0; |
| } |
| |
| static void destroy_unselected_subchannels_locked(pick_first_lb_policy* p) { |
| for (size_t i = 0; i < p->subchannel_list->num_subchannels; ++i) { |
| grpc_lb_subchannel_data* sd = &p->subchannel_list->subchannels[i]; |
| if (p->selected != sd) { |
| grpc_lb_subchannel_data_unref_subchannel(sd, |
| "selected_different_subchannel"); |
| } |
| } |
| } |
| |
| static grpc_connectivity_state pf_check_connectivity_locked( |
| grpc_lb_policy* pol, grpc_error** error) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)pol; |
| return grpc_connectivity_state_get(&p->state_tracker, error); |
| } |
| |
| static void pf_notify_on_state_change_locked(grpc_lb_policy* pol, |
| grpc_connectivity_state* current, |
| grpc_closure* notify) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)pol; |
| grpc_connectivity_state_notify_on_state_change(&p->state_tracker, current, |
| notify); |
| } |
| |
| static void pf_ping_one_locked(grpc_lb_policy* pol, grpc_closure* on_initiate, |
| grpc_closure* on_ack) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)pol; |
| if (p->selected) { |
| grpc_connected_subchannel_ping(p->selected->connected_subchannel, |
| on_initiate, on_ack); |
| } else { |
| GRPC_CLOSURE_SCHED(on_initiate, |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("Not connected")); |
| GRPC_CLOSURE_SCHED(on_ack, |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("Not connected")); |
| } |
| } |
| |
| static void pf_connectivity_changed_locked(void* arg, grpc_error* error); |
| |
| static void pf_update_locked(grpc_lb_policy* policy, |
| const grpc_lb_policy_args* args) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)policy; |
| const grpc_arg* arg = |
| grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES); |
| if (arg == nullptr || arg->type != GRPC_ARG_POINTER) { |
| if (p->subchannel_list == nullptr) { |
| // If we don't have a current subchannel list, go into TRANSIENT FAILURE. |
| grpc_connectivity_state_set( |
| &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("Missing update in args"), |
| "pf_update_missing"); |
| } else { |
| // otherwise, keep using the current subchannel list (ignore this update). |
| gpr_log(GPR_ERROR, |
| "No valid LB addresses channel arg for Pick First %p update, " |
| "ignoring.", |
| (void*)p); |
| } |
| return; |
| } |
| const grpc_lb_addresses* addresses = |
| (const grpc_lb_addresses*)arg->value.pointer.p; |
| if (grpc_lb_pick_first_trace.enabled()) { |
| gpr_log(GPR_INFO, "Pick First %p received update with %lu addresses", |
| (void*)p, (unsigned long)addresses->num_addresses); |
| } |
| grpc_lb_subchannel_list* subchannel_list = grpc_lb_subchannel_list_create( |
| &p->base, &grpc_lb_pick_first_trace, addresses, args, |
| pf_connectivity_changed_locked); |
| if (subchannel_list->num_subchannels == 0) { |
| // Empty update or no valid subchannels. Unsubscribe from all current |
| // subchannels and put the channel in TRANSIENT_FAILURE. |
| grpc_connectivity_state_set( |
| &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("Empty update"), |
| "pf_update_empty"); |
| if (p->subchannel_list != nullptr) { |
| grpc_lb_subchannel_list_shutdown_and_unref(p->subchannel_list, |
| "sl_shutdown_empty_update"); |
| } |
| p->subchannel_list = subchannel_list; // Empty list. |
| p->selected = nullptr; |
| return; |
| } |
| if (p->selected == nullptr) { |
| // We don't yet have a selected subchannel, so replace the current |
| // subchannel list immediately. |
| if (p->subchannel_list != nullptr) { |
| grpc_lb_subchannel_list_shutdown_and_unref(p->subchannel_list, |
| "pf_update_before_selected"); |
| } |
| p->subchannel_list = subchannel_list; |
| } else { |
| // We do have a selected subchannel. |
| // Check if it's present in the new list. If so, we're done. |
| for (size_t i = 0; i < subchannel_list->num_subchannels; ++i) { |
| grpc_lb_subchannel_data* sd = &subchannel_list->subchannels[i]; |
| if (sd->subchannel == p->selected->subchannel) { |
| // The currently selected subchannel is in the update: we are done. |
| if (grpc_lb_pick_first_trace.enabled()) { |
| gpr_log(GPR_INFO, |
| "Pick First %p found already selected subchannel %p " |
| "at update index %" PRIuPTR " of %" PRIuPTR "; update done", |
| p, p->selected->subchannel, i, |
| subchannel_list->num_subchannels); |
| } |
| if (p->selected->connected_subchannel != nullptr) { |
| sd->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF( |
| p->selected->connected_subchannel, "pf_update_includes_selected"); |
| } |
| p->selected = sd; |
| if (p->subchannel_list != nullptr) { |
| grpc_lb_subchannel_list_shutdown_and_unref( |
| p->subchannel_list, "pf_update_includes_selected"); |
| } |
| p->subchannel_list = subchannel_list; |
| destroy_unselected_subchannels_locked(p); |
| grpc_lb_subchannel_list_ref_for_connectivity_watch( |
| subchannel_list, "connectivity_watch+replace_selected"); |
| grpc_lb_subchannel_data_start_connectivity_watch(sd); |
| // If there was a previously pending update (which may or may |
| // not have contained the currently selected subchannel), drop |
| // it, so that it doesn't override what we've done here. |
| if (p->latest_pending_subchannel_list != nullptr) { |
| grpc_lb_subchannel_list_shutdown_and_unref( |
| p->latest_pending_subchannel_list, |
| "pf_update_includes_selected+outdated"); |
| p->latest_pending_subchannel_list = nullptr; |
| } |
| return; |
| } |
| } |
| // Not keeping the previous selected subchannel, so set the latest |
| // pending subchannel list to the new subchannel list. We will wait |
| // for it to report READY before swapping it into the current |
| // subchannel list. |
| if (p->latest_pending_subchannel_list != nullptr) { |
| if (grpc_lb_pick_first_trace.enabled()) { |
| gpr_log(GPR_DEBUG, |
| "Pick First %p Shutting down latest pending subchannel list " |
| "%p, about to be replaced by newer latest %p", |
| (void*)p, (void*)p->latest_pending_subchannel_list, |
| (void*)subchannel_list); |
| } |
| grpc_lb_subchannel_list_shutdown_and_unref( |
| p->latest_pending_subchannel_list, "sl_outdated_dont_smash"); |
| } |
| p->latest_pending_subchannel_list = subchannel_list; |
| } |
| // If we've started picking, start trying to connect to the first |
| // subchannel in the new list. |
| if (p->started_picking) { |
| grpc_lb_subchannel_list_ref_for_connectivity_watch( |
| subchannel_list, "connectivity_watch+update"); |
| grpc_lb_subchannel_data_start_connectivity_watch( |
| &subchannel_list->subchannels[0]); |
| } |
| } |
| |
| static void pf_connectivity_changed_locked(void* arg, grpc_error* error) { |
| grpc_lb_subchannel_data* sd = (grpc_lb_subchannel_data*)arg; |
| pick_first_lb_policy* p = (pick_first_lb_policy*)sd->subchannel_list->policy; |
| if (grpc_lb_pick_first_trace.enabled()) { |
| gpr_log(GPR_DEBUG, |
| "Pick First %p connectivity changed for subchannel %p (%" PRIuPTR |
| " of %" PRIuPTR |
| "), subchannel_list %p: state=%s p->shutdown=%d " |
| "sd->subchannel_list->shutting_down=%d error=%s", |
| (void*)p, (void*)sd->subchannel, |
| sd->subchannel_list->checking_subchannel, |
| sd->subchannel_list->num_subchannels, (void*)sd->subchannel_list, |
| grpc_connectivity_state_name(sd->pending_connectivity_state_unsafe), |
| p->shutdown, sd->subchannel_list->shutting_down, |
| grpc_error_string(error)); |
| } |
| // If the policy is shutting down, unref and return. |
| if (p->shutdown) { |
| grpc_lb_subchannel_data_stop_connectivity_watch(sd); |
| grpc_lb_subchannel_data_unref_subchannel(sd, "pf_shutdown"); |
| grpc_lb_subchannel_list_unref_for_connectivity_watch(sd->subchannel_list, |
| "pf_shutdown"); |
| return; |
| } |
| // If the subchannel list is shutting down, stop watching. |
| if (sd->subchannel_list->shutting_down || error == GRPC_ERROR_CANCELLED) { |
| grpc_lb_subchannel_data_stop_connectivity_watch(sd); |
| grpc_lb_subchannel_data_unref_subchannel(sd, "pf_sl_shutdown"); |
| grpc_lb_subchannel_list_unref_for_connectivity_watch(sd->subchannel_list, |
| "pf_sl_shutdown"); |
| return; |
| } |
| // If we're still here, the notification must be for a subchannel in |
| // either the current or latest pending subchannel lists. |
| GPR_ASSERT(sd->subchannel_list == p->subchannel_list || |
| sd->subchannel_list == p->latest_pending_subchannel_list); |
| // Update state. |
| sd->curr_connectivity_state = sd->pending_connectivity_state_unsafe; |
| // Handle updates for the currently selected subchannel. |
| if (p->selected == sd) { |
| // If the new state is anything other than READY and there is a |
| // pending update, switch to the pending update. |
| if (sd->curr_connectivity_state != GRPC_CHANNEL_READY && |
| p->latest_pending_subchannel_list != nullptr) { |
| p->selected = nullptr; |
| grpc_lb_subchannel_data_stop_connectivity_watch(sd); |
| grpc_lb_subchannel_list_unref_for_connectivity_watch( |
| sd->subchannel_list, "selected_not_ready+switch_to_update"); |
| grpc_lb_subchannel_list_shutdown_and_unref( |
| p->subchannel_list, "selected_not_ready+switch_to_update"); |
| p->subchannel_list = p->latest_pending_subchannel_list; |
| p->latest_pending_subchannel_list = nullptr; |
| grpc_connectivity_state_set( |
| &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, |
| GRPC_ERROR_REF(error), "selected_not_ready+switch_to_update"); |
| } else { |
| // TODO(juanlishen): we re-resolve when the selected subchannel goes to |
| // TRANSIENT_FAILURE because we used to shut down in this case before |
| // re-resolution is introduced. But we need to investigate whether we |
| // really want to take any action instead of waiting for the selected |
| // subchannel reconnecting. |
| if (sd->curr_connectivity_state == GRPC_CHANNEL_SHUTDOWN || |
| sd->curr_connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) { |
| // If the selected channel goes bad, request a re-resolution. |
| grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_IDLE, |
| GRPC_ERROR_NONE, |
| "selected_changed+reresolve"); |
| p->started_picking = false; |
| grpc_lb_policy_try_reresolve(&p->base, &grpc_lb_pick_first_trace, |
| GRPC_ERROR_NONE); |
| } else { |
| grpc_connectivity_state_set(&p->state_tracker, |
| sd->curr_connectivity_state, |
| GRPC_ERROR_REF(error), "selected_changed"); |
| } |
| if (sd->curr_connectivity_state != GRPC_CHANNEL_SHUTDOWN) { |
| // Renew notification. |
| grpc_lb_subchannel_data_start_connectivity_watch(sd); |
| } else { |
| p->selected = nullptr; |
| grpc_lb_subchannel_data_stop_connectivity_watch(sd); |
| grpc_lb_subchannel_list_unref_for_connectivity_watch( |
| sd->subchannel_list, "pf_selected_shutdown"); |
| grpc_lb_subchannel_data_unref_subchannel(sd, "pf_selected_shutdown"); |
| } |
| } |
| return; |
| } |
| // If we get here, there are two possible cases: |
| // 1. We do not currently have a selected subchannel, and the update is |
| // for a subchannel in p->subchannel_list that we're trying to |
| // connect to. The goal here is to find a subchannel that we can |
| // select. |
| // 2. We do currently have a selected subchannel, and the update is |
| // for a subchannel in p->latest_pending_subchannel_list. The |
| // goal here is to find a subchannel from the update that we can |
| // select in place of the current one. |
| switch (sd->curr_connectivity_state) { |
| case GRPC_CHANNEL_READY: { |
| // Case 2. Promote p->latest_pending_subchannel_list to |
| // p->subchannel_list. |
| if (sd->subchannel_list == p->latest_pending_subchannel_list) { |
| GPR_ASSERT(p->subchannel_list != nullptr); |
| grpc_lb_subchannel_list_shutdown_and_unref(p->subchannel_list, |
| "finish_update"); |
| p->subchannel_list = p->latest_pending_subchannel_list; |
| p->latest_pending_subchannel_list = nullptr; |
| } |
| // Cases 1 and 2. |
| grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_READY, |
| GRPC_ERROR_NONE, "connecting_ready"); |
| sd->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF( |
| grpc_subchannel_get_connected_subchannel(sd->subchannel), |
| "connected"); |
| p->selected = sd; |
| if (grpc_lb_pick_first_trace.enabled()) { |
| gpr_log(GPR_INFO, "Pick First %p selected subchannel %p", (void*)p, |
| (void*)sd->subchannel); |
| } |
| // Drop all other subchannels, since we are now connected. |
| destroy_unselected_subchannels_locked(p); |
| // Update any calls that were waiting for a pick. |
| grpc_lb_policy_pick_state* pick; |
| while ((pick = p->pending_picks)) { |
| p->pending_picks = pick->next; |
| pick->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF( |
| p->selected->connected_subchannel, "picked"); |
| if (grpc_lb_pick_first_trace.enabled()) { |
| gpr_log(GPR_INFO, |
| "Servicing pending pick with selected subchannel %p", |
| (void*)p->selected); |
| } |
| GRPC_CLOSURE_SCHED(pick->on_complete, GRPC_ERROR_NONE); |
| } |
| // Renew notification. |
| grpc_lb_subchannel_data_start_connectivity_watch(sd); |
| break; |
| } |
| case GRPC_CHANNEL_TRANSIENT_FAILURE: { |
| grpc_lb_subchannel_data_stop_connectivity_watch(sd); |
| do { |
| sd->subchannel_list->checking_subchannel = |
| (sd->subchannel_list->checking_subchannel + 1) % |
| sd->subchannel_list->num_subchannels; |
| sd = &sd->subchannel_list |
| ->subchannels[sd->subchannel_list->checking_subchannel]; |
| } while (sd->subchannel == nullptr); |
| // Case 1: Only set state to TRANSIENT_FAILURE if we've tried |
| // all subchannels. |
| if (sd->subchannel_list->checking_subchannel == 0 && |
| sd->subchannel_list == p->subchannel_list) { |
| grpc_connectivity_state_set( |
| &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, |
| GRPC_ERROR_REF(error), "connecting_transient_failure"); |
| } |
| // Reuses the connectivity refs from the previous watch. |
| grpc_lb_subchannel_data_start_connectivity_watch(sd); |
| break; |
| } |
| case GRPC_CHANNEL_CONNECTING: |
| case GRPC_CHANNEL_IDLE: { |
| // Only update connectivity state in case 1. |
| if (sd->subchannel_list == p->subchannel_list) { |
| grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_CONNECTING, |
| GRPC_ERROR_REF(error), |
| "connecting_changed"); |
| } |
| // Renew notification. |
| grpc_lb_subchannel_data_start_connectivity_watch(sd); |
| break; |
| } |
| case GRPC_CHANNEL_SHUTDOWN: { |
| grpc_lb_subchannel_data_stop_connectivity_watch(sd); |
| grpc_lb_subchannel_data_unref_subchannel(sd, "pf_candidate_shutdown"); |
| // Advance to next subchannel and check its state. |
| grpc_lb_subchannel_data* original_sd = sd; |
| do { |
| sd->subchannel_list->checking_subchannel = |
| (sd->subchannel_list->checking_subchannel + 1) % |
| sd->subchannel_list->num_subchannels; |
| sd = &sd->subchannel_list |
| ->subchannels[sd->subchannel_list->checking_subchannel]; |
| } while (sd->subchannel == nullptr && sd != original_sd); |
| if (sd == original_sd) { |
| grpc_lb_subchannel_list_unref_for_connectivity_watch( |
| sd->subchannel_list, "pf_exhausted_subchannels"); |
| if (sd->subchannel_list == p->subchannel_list) { |
| grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_IDLE, |
| GRPC_ERROR_NONE, |
| "exhausted_subchannels+reresolve"); |
| p->started_picking = false; |
| grpc_lb_policy_try_reresolve(&p->base, &grpc_lb_pick_first_trace, |
| GRPC_ERROR_NONE); |
| } |
| } else { |
| if (sd->subchannel_list == p->subchannel_list) { |
| grpc_connectivity_state_set( |
| &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, |
| GRPC_ERROR_REF(error), "subchannel_failed"); |
| } |
| // Reuses the connectivity refs from the previous watch. |
| grpc_lb_subchannel_data_start_connectivity_watch(sd); |
| } |
| } |
| } |
| } |
| |
| static void pf_set_reresolve_closure_locked( |
| grpc_lb_policy* policy, grpc_closure* request_reresolution) { |
| pick_first_lb_policy* p = (pick_first_lb_policy*)policy; |
| GPR_ASSERT(!p->shutdown); |
| GPR_ASSERT(policy->request_reresolution == nullptr); |
| policy->request_reresolution = request_reresolution; |
| } |
| |
| static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = { |
| pf_destroy, |
| pf_shutdown_locked, |
| pf_pick_locked, |
| pf_cancel_pick_locked, |
| pf_cancel_picks_locked, |
| pf_ping_one_locked, |
| pf_exit_idle_locked, |
| pf_check_connectivity_locked, |
| pf_notify_on_state_change_locked, |
| pf_update_locked, |
| pf_set_reresolve_closure_locked}; |
| |
| static void pick_first_factory_ref(grpc_lb_policy_factory* factory) {} |
| |
| static void pick_first_factory_unref(grpc_lb_policy_factory* factory) {} |
| |
| static grpc_lb_policy* create_pick_first(grpc_lb_policy_factory* factory, |
| grpc_lb_policy_args* args) { |
| GPR_ASSERT(args->client_channel_factory != nullptr); |
| pick_first_lb_policy* p = (pick_first_lb_policy*)gpr_zalloc(sizeof(*p)); |
| if (grpc_lb_pick_first_trace.enabled()) { |
| gpr_log(GPR_DEBUG, "Pick First %p created.", (void*)p); |
| } |
| pf_update_locked(&p->base, args); |
| grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable, args->combiner); |
| grpc_subchannel_index_ref(); |
| return &p->base; |
| } |
| |
| static const grpc_lb_policy_factory_vtable pick_first_factory_vtable = { |
| pick_first_factory_ref, pick_first_factory_unref, create_pick_first, |
| "pick_first"}; |
| |
| static grpc_lb_policy_factory pick_first_lb_policy_factory = { |
| &pick_first_factory_vtable}; |
| |
| static grpc_lb_policy_factory* pick_first_lb_factory_create() { |
| return &pick_first_lb_policy_factory; |
| } |
| |
| /* Plugin registration */ |
| |
| void grpc_lb_policy_pick_first_init() { |
| grpc_register_lb_policy(pick_first_lb_factory_create()); |
| } |
| |
| void grpc_lb_policy_pick_first_shutdown() {} |
